The Problem with Counting Net Carbs

People who eat a low carb or ketogenic diet often ask me about calculating “net carbs” and are surprised by my reply, as it differs from what they’ve read online. The commonly held advice is to subtract “fiber” from the total amount of carbohydrate on the label to arrive at “net carbs” can lead to an underestimation of nutrient intake, as well as possibly an underestimation of the effect of the food on blood glucose and insulin release when those foods are processed into other foods by grinding and/or heating.

As with other meal pattern types, a “whole foods” approach when following a low-carb lifestyle is preferable. That doesn’t mean that people shouldn’t enjoy the occasional low-carb treat, as long as they understand that a baked good prepared from almond flour is not equivalent in terms of nutrient availability to the whole almonds from which it is made.

“Net Carbs” and the Perils of Food Processing

As covered in detail in two previous articles called The Perils of Food Processing (Part 1 is here and Part 2 is here),  I showed that both the amount and type of food processing applied to a food impacts the amount of nutrients available for absorption by the body, as well as having varying effects on the body’s insulin and blood sugar response. 

“Food processing” in this context means that amount that a food undergoes cutting or grinding and/or cooking in someway, including baking. Mechanical processing, such pounding or grinding food is an ancient form of food processing which has an effect on how many nutrients are available to be digested.

That is, the nutrients available to the body when food is eaten raw and whole versus raw and pounded is significant, and this holds true whether the food is animal protein such as meat or a starchy vegetable such as sweet potato. It is also true for foods such as almonds.

The availability of carbohydrate and energy is different for whole, raw almonds versus ground almonds such as almond flour — a staple in low carb and keto baking. More on that, below.

Changes in Insulin and Blood Glucose Response Resulting from Food Processing

As covered in the first article linked to above, mechanical processing of a food doesn’t change the amount of carbohydrate that is in it. That is, when we compare 60 g of whole apple with 60 g of pureed apple or 60 g of juiced apple, there is the same amount of carbohydrate in each. The Glycemic Index of these three are very similar so this isn’t very helpful to inform about the blood glucose response to actually eating these different foods.

When these foods are eaten, the insulin response and blood glucose response 90 minutes later is significantly  different.

As can be seen by the graph on the right, in healthy individuals blood insulin level goes very high with the juiced apple and in response, blood glucose then goes very low, below baseline. The response seen with the juiced apple is typical of what is seen with ultra-processed carbohydrates. 

The Effect of Mechanical Processing of Fruit on Blood Glucose Response – Gabor Erdosi – Food News 2018

The same effect that is true for fruit is true when grain is ground; plasma insulin response increases the smaller the particle size of the grain.

The Effect of Mechanical Processing of Wheat on Blood Glucose Response – Gabor Erdosi – Food News 2018

Whole grain releases less insulin than the same amount of cracked grains, which is less than the same amount of course flour. The highest amount of insulin is released in response to eating the same amount of fine flour.

What is true for wheat is also true for rice and of interest, there isn’t a big difference between the insulin response with brown rice versus white rice.

The Effect of Mechanical Processing of Rice on Blood Glucose Response – Gabor Erdosi – Food News 2018

While there is no difference in the Glycemic Index or Glycemic Load of whole wheat versus ground wheat or whole rice versus ground rice, there is a huge difference in the insulin response with difference types of mechanical processing.

Also as outlined in the previous articles (links above), the amount of fiber that was in the grain did not make a difference in the amount of insulin released, only the amount of mechanical processing of the grain. So, eating brown rice versus white rice won’t change the amount of insulin that is released.

Remember, insulin is a hormone that signals the body to store energy (calories), so increased insulin response in response to grinding food is important.

In short, it is the amount of cell disruption caused by grinding that increases insulin and glucose response; not the specific amount of carbohydrate in the whole food, nor the amount of fiber in the food.

For those with Type 2 Diabetes or pre-diabetes, applying “net carb” calculations to foods that have been ground is a problem; as it does not take into account the increased insulin release and resulting change in glucose response, as well as the change in energy availability caused by the grinding.

NOTE (June 2 2019): The fiber in the whole food and the ground food remains unchanged and is indigestible by the body, although it is digested by the gut microbiome into fatty acids. While fiber may slow the gastric emptying of the ground product (compared to the same product with the fiber removed), in and by itself the presence of fiber in the ground product compared to the whole food does not reduce the impact on insulin and glycemic response that the grinding causes. 

The Effect of Cooking on Nutrient Availability

Also as documented in the first of the two articles on food processing, cooking also has an effect on nutrient availability. When grains are cooked they become much more digestible – meaning that more of the nutrients are available to be absorbed. In the case of potatoes, there is double or triple the amount of energy (calories) available to the body when they are cooked versus when they are raw and these calories are now available to the body where they weren’t when they were raw.

When foods that are high in fat (lipid) such as peanuts are cooked, the amount of energy the body is able to derive from the food, increases.

The Effect of Cooking Lipid (fat) and Protein-rich Foods on Nutrient Availability – Gabor Erdosi Food News 2018
Does Food Processing Affect Almonds?

Yesterday, in preparing to write this article, I was curious if there was any information available specifically about almonds as almond flour is used in most low-carb and “keto” baked goods.

I went looking and found a September 2016 article in the International Journal of Food Science and Technology titled “A review of the impact of processing on nutrient bioaccessibility and digestion of almonds”[1] which documents the most common processing technique used on almonds and their effect on the digestion of nutrients.

In short, lab studies and animal and human studies demonstrate that there are marked differences in the way various forms of almonds (whole raw, whole roasted, blanched, milled flour) are digested and the amount of different macronutrients that are absorbed.

What is true with grinding grain, apples and peanuts holds true for almonds.

It is reasonable to assume that the body’s release of insulin and the corresponding glucose response is similarly changed by the increased bioavailablity of nutrients in those processed foods.

Ultra-processed foods, whether fruit, grains, or nuts are not treated by the body the same as whole, unprocessed foods. The macronutrient availability (i.e. amount of carbohydrate and energy) in whole, unprocessed foods is not the same as in the same foods that have been ground and/or heated, and the amount of insulin released and glucose absorbed can differ too.

Final Thoughts on “Net Carbs”

One cannot simply subtract the fiber that is contained in the whole, unprocessed food from the total carbohydrate content of the processed food and arrive at “net carbs” because the amount of macronutrient absorption of the food is increased due to the cell disruption of grinding and heating. For those with Type 2 Diabetes or pre-diabetes, one also needs to factor in the differential impact on insulin and blood glucose release that results from the food processing.

One can subtract the fiber in whole, raw almonds and arrive at “net carbs” on the assumption that the fiber is indigestible by the body and that the other nutrients listed on the label apply to the food in it’s current form, but roasting and grinding those same almonds into almond butter or grinding those almonds into almond flour and then baking (i.e. cooking) them into a host of low carb or keto ‘treats’ on the basis of their low “net carb” content can significantly underestimate their total macronutrient content. 

Should one choose to use the idea of “net carbs”, it should be applied only to whole, unprocessed (not ground or heated) foods.

Ultra-processed foods, irrespective of the carbohydrate content of the original whole, unprocessed foods from which they are made are not equivalent in nutrient availability or the body’s response to them as to whole, unprocessed foods. 

While low-carb and keto ‘treats’ may be nice as “sometimes foods”, they are not ideal as “everyday foods” if weight loss and lowering blood glucose and insulin response are goals.

More Info?

If you would like to know more about following a low carbohydrate lifestyle or to adopt it for health reasons, I can help. You can learn more about my services under the Services tab or in the Shop. If you have questions, please feel free to send me a note using the Contact Me form above and I will reply as soon as I can.

To your good health!

Joy

You can follow me on:

Twitter: https://twitter.com/lchfRD
Facebook: https://www.facebook.com/lchfRD/
Instagram: https://www.instagram.com/lchf_rd

Copyright ©2019 The LCHF-Dietitian (a division of BetterByDesign Nutrition Ltd.)

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the “content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

Reference

  1. Grundy MM, Lapsley K, Ellis PR. A review of the impact of processing on nutrient bioaccessibility and digestion of almonds. Int J Food Sci Technol. 2016;51(9):1937–1946. doi:10.1111/ijfs.13192          

How Carb-Containing Food Affects Blood Sugar Compared to Table Sugar

According to Dr. David Unwin, a UK general practitioner (family doctor) and published researcher whose practice focuses on helping people put their diabetes and pre-diabetes into remission,  blood sugar (glycemic) response to carbohydrate containing foods is what matters in both diabetes and obesity, and is even more than the absolute amount of carbohydrate in those foods. For Dr. Unwin, the challenge was to represent the effect of high Glycemic Index (GI) foods on people’s blood sugar in terms that could be easily understood. This article is about some of the infographics that Dr. Unwin has developed to help people more easily understand the concept of Glycemic Load*. 

*Note: I think it is important to cover a range of ways that credible individuals view important concepts. Dr. Unwin’s view of blood sugar response as it relates to Glycemic Load (GL) is only one of the ways that glycemic response is understood. The most obvious limitation is that GI measures blood sugar response as if the food is eaten alone, which rarely occurs.

UPDATE (May 14, 2019) Findings of a lack of reliability in Glycemic Index values is outlined in the next article, which can be accessed by clicking here.


In two earlier articles, I explained what the Glycemic Index (GI) and Glycemic Load (GL) are, as well as the challenges with using them.

In short, the Glycemic Index (GI) ranks the carbohydrate content of food in terms of their effect on blood sugar compared to a meal of pure glucose (which is counted as 100).

Using the Glycemic Index often causes confusion because it fails to compensate for the density of each carbohydrate in a particular portion of food. That is why Glycemic Load (GL) was created, which is given as grams of glucose for a specified portion of a food. The problem is, most people have no understanding of glucose and it’s metabolic effects and as Dr. David Unwin, a General Practitioner explained in the paper below (1), many healthcare professionals also have misconceptions about the effect of food-based carbohydrates on blood sugar, as compared to glucose.

Blood Sugar Response as a Patient tool

Dr. Unwin thought that in order to best use Glycemic Load to explain blood sugar response, that it would be more helpful for patients with pre-diabetes or diabetes to be able to understand the effect on blood sugar of eating specific by comparing them to the more familiar sugar, ordinary table sugar.  Dr. Unwin developed some infographics that explain glycemic response in comparison to one (4 g) teaspoon of table sugar.

While table sugar is made up of both glucose and fructose, patients are able to understand the table sugar analogy without being confused by what glucose is (the standard used in the Glycemic Index and Glycemic Load). 

Glycemic Load translated to Blood Sugar Response as a tool for Healthcare Practioners

Dr. Unwin’s and his colleagues had noted that healthcare professionals were making decisions based on Glycemic Index (GI) and assumed that carbohydrate-based foods have a lower GI than table sugar, which is not necessarily the case.

For example, the GI of table sugar is 65, but foods such as basmati rice (GI 69), whole wheat bread (GI 74) and baked potato (GI 86) have higher GIs. This incorrect assumption about many carb-based foods by healthcare professional affected food choices being recommended by them and which were then adopted by their patients, adversely impacting their blood sugar levels.

While Dr. Unwin expressed that health practitioners would be better to refer to Glycemic Load (GL) which takes into account the carbohydrate content of the food in terms of a likely portion size for that food, the concept of GL is not easily understood by their patients. That is where Dr. Unwin’s infographics may play a role.

Blood Sugar Response – a tool for people with diabetes and pre-diabetes

Below is one of the infographics developed by Dr. Unwin to explain Glycemic Index in terms of standard serving sizes (i.e. Glycemic Load) with a corresponding explanation of how that quantity of common foods affects blood sugar compared to one (4g) teaspoon of ordinary table sugar.

Infographic for health professionals to show how the glycemic index helps inform dietary choices.

In the infographic below, I’ve taken just 3 of the foods above and represented these three foods (1) visually (2) in imperial quantities and (3) in metric quantities.

Visual representation, imperial and metric portion sizes of 3 foods (Joy Y. Kiddie, MSc, RD)

In my experience people rarely eat the common portion size of foods, whether it is the recommended portion size listed in national food guides or in the Glycemic Index.

Common Portion Sizes rather than Normal Portion Sizes

As a Dietitian, I’ve come to realize that while the standard portion for cooked rice is given as a 1 cup (150 g) serving, many people eat more than 1 cup of rice at a time. In fact, the standard portion of rice in the old Canada’s Food Guide (which had recommended portions) was 1/2 cup (125 ml), which is half this amount!

The standard portion of spaghetti in the old Canada’s Food Guide was 1/2 cup (125 ml) which is half the amount listed in the GI portions and one has to ask how many people really limit their servings to 1 cups of spaghetti?  It is my experience that most people who are not restricting portions often eat 2 cups of spaghetti or more; which raises blood sugar as much as 13.2 tsp of sugar; and that is not yet counting the sauce that goes on the spaghetti!

Some adults eat only 3 small boiled baby potatoes at a time too but even if they do, that raises blood sugar as much as 9.1 tsp of table sugar!

Below are some other infographics developed by Dr. Unwin that demonstrate ordinary foods in terms of their effect on blood sugar compared to a teaspoons (4g) of ordinary table sugar.

I find the similarity between white bread and brown bread interesting. Not much difference, and if one makes a sandwich or 2 pieces of toast for breakfast, whether its white or brown bread, it raises blood sugar as much as 6- 1/2  and 7- 1/2 tsp of sugar…and that is before putting anything on the bread! 

Infographic for health professionals to show how bread products affect blood sugar (Dr. Unwin, from Public Health Collaborative https://phcuk.org/nice/)

Below is an infographic for servings of cereal, but again how many people limit themselves to 30g (1/2 cup) of cereal for breakfast? In my experience, most adults eat 1 cup of cereal as a serving, often more.

Infographic for health professionals to show how cereal products affect blood sugar (Dr. Unwin, from Public Health Collaborative https://phcuk.org/nice/)

Below is one of Dr. Unwin’s infographics with respect to fruit.

Again, the serving size here is much smaller than what is a “usual” serving in my experience.  For example, most people I’ve worked with eat a whole large banana, which is double this serving (and has the same blood glucose response as 11- 1/2 tsp of sugar).

Th fruit infographic below will also help explain why I recommend berries such as strawberries in 1/2 cup servings (which only affect blood glucose as much as a little over a tsp of table sugar).

Infographic for health professionals to show how various fruit affect blood sugar (Dr. Unwin, from Public Health Collaborative https://phcuk.org/nice/)

Some final thoughts…

As mentioned above, there are different views regarding how different carb-containing foods impact blood glucose levels. Dr. Unwin’s infographics are certainly helpful for people to better understand the concept of Glycemic Load.


If you have been recently diagnosed as having pre-diabetes or as having type 2 diabetes (T2D) and would like to work on reversing the symptoms by adopting a low carbohydrate lifestyle, I can help.

You can learn more about my services including individual hourly appointments and sessions as well as packages above under the Services tab or in the Shop.

If you have questions, please feel free to send me a note using the Contact Me form above and I will reply as soon as I can.

To your good health!

Joy

About Dr. Unwin

Dr. David Unwin, MD, is a UK general practitioner (family doctor) known for pioneering a low-carb approach to managing diabetes in the UK who won the prestigious NHS Innovator of the Year award in 2016 for his work with diabetes patients. He serves as medical advisor to the Low Carb Program which is an online platform approved by the NHS and aimed and helping individuals put type 2 diabetes and prediabetes into remission.

In 2017-2018, Dr. Unwin’s practice saved £57,000 ($99,445 CDN / $74,077 USD) on drugs for type 2 diabetes, hypertension and other conditions by offering patients a dietary alternative to medications.

In 2018, Dr. Unwin was named the 9th most influential General Practitioner (GP) in the UK by GP magazine and has written several peer-reviewed papers related to low-carbohydrate diets.

You can follow me on:

Twitter: https://twitter.com/lchfRD
Facebook: https://www.facebook.com/lchfRD/
Instagram: https://www.instagram.com/lchf_rd

Copyright ©2019 The LCHF-Dietitian (a division of BetterByDesign Nutrition Ltd.)

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the “content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

Reference

Unwin D, Haslam D, Livesey G. It is the glycaemic response to, not the carbohydrate content of food that matters in diabetes and obesity: The glycaemic index revisited. Journal of Insulin Resistance. 2016;1(1), a8. http://dx.doi.org/10.4102/jir.v1i1.8

Complex Carbohydrates as Long Chains of Sugar Molecules

An analogy is a comparison between similar ideas to help illustrate one of them. The featured photo for this post are sugar crystals on a string and the reason for this will become clear.

The idea for this article came when someone I follow on social media (Dr. RD Dikeman*) posted the graphic below, which shows complex carbohydrates as long strings of glucose, which starches are. But there are also other types of complex carbohydrates that are long strings of different sugar molecules that can impact blood glucose differently. I thought a simple explanation of what “complex carbohydrates” are, how they are digested and how these can affect blood sugar differently might be helpful, so that is what this article is about.

graphic from RD Dikeman, Typeonegrit

*Dr. RD Dikeman holds a PhD in Theoretic and Mathematical Physics and has become very knowledgeable in carbohydrate metabolism as a result of his son having been diagnosed in 2013 with Type 1 Diabetes. His son was eating 40-60 g of carbohydrate per meal and was experiencing a “roller-coaster ride” of high and low blood sugars, including an incidence of “ketoacidosis”; which is a life-threatening condition when the body produces high levels of ketones due to an insufficiency of insulin. This should not be confused with “ketosis” where the body switches to using fat stores for energy, such as after an overnight fast. Five years ago, Dr. Dikeman’s son began to follow the low carbohydrate protocol of Dr. Richard Bernstein MD (outlined in his book “Diabetes Solution”) and since that time has been able to maintain normal normal blood sugar levels with the minimum required doses of insulin. 

I liked the analogy of Dr. Dikeman’s graphic and wanted to use it as a ‘jumping off point’ for this article.

Glucose Explain Simply

Glucose (also called dextrose) is the type of sugar found in the blood which is why the common term “blood sugar” and the more clinical term “blood glucose” refer to the same thing.

Glucose is one of the two sources of energy (along with ketones) that are used to fuel the body’s cells. Even people that don’t eat “low carb” will make ketones after a night’s sleep, so the body of healthy people runs on both glucose and ketones.

The carb-containing foods that we eat are broken down into glucose for energy or the body makes the glucose it needs for the brain and red blood cells from other substances in a process called gluconeogenesis.

The Glucose-Complex Carb Analogy

In the graphic above, Dr. Dikeman questions whether people such as Diabetics that have trouble metabolizing glucose should be eating complex carbohydrates that are essentially just long strings of glucose molecules strung together like beads on a chain.

As in Dr. Dikeman’s illustration, some complex carbohydrates such as starch are just long chains of glucose molecules, however other complex carbohydrates are made up of other sugars such as galactose and fructose, along with glucose. Because of that I wanted to expand on Dr. Dikeman’s illustration.

Simple and Complex Carbs

One way that carbs are sometimes classified is as “simple” or “complex”; with starch and fiber being categorized as complex carbs and all sugars being categorized as simple carbs.

Simple Sugars

There are two types of simple sugars; monosaccharides and disaccharides.

Mono means “one” and saccharides means “sugar” so a monosaccharide is just a single sugar molecule. Di means “two”, so a disaccharide is two sugar molecules joined together.

Monosaccharides

As mentioned above, monosaccharides are made up of only a single sugar molecule and examples of these are glucose, fructose and galactose. All three monosaccharides have 6 carbons and the same chemical formula but look entirely different from each other. For example, glucose and galactose are 6-ring sugars and fructose is a 5-ring sugar.

Glucose is usually found in food bound either to other glucose molecules, as in Dr. Dikeman’s illustration above, or may be bound to other types of sugar molecules in a disaccharide (2 sugar molecules) or a starch or fiber (long chain of sugar molecules).

Fructose is the sugar found in fruit and since it is a 5-ring sugar, it can’t simply be broken down into glucose, which is a 6 ring sugar.

Galactose is a six ring sugar that rarely exists on its own in food but that can be broken down in the body through digestion. It is usually found bound to glucose to form lactose, the sugar found in milk and dairy products.

Disaccharides

Disaccharides are two monosaccharide sugar molecules bound together.

Sucrose is ordinary table sugar and made up of glucose-fructose.

Lactose is the sugar in milk and milk products and is glucuse-galactose

Maltose which rarely occurs naturally in foods, is glucose-glucose. Maltose is used in food processing such as the shiny glaze on Chinese roast duck.

complex carbohydrates

Complex carbohydrates are made up of more than two monosaccharides (sugar molecules). Oligosaccharides (where oligo means “scant” or “few”) are made up of 3-10 sugar molecules, whereas polysaccharides are made up of hundred or even thousands of monosaccharides (sugar molecules).

Oligosaccharides

Oligosaccharides are made up of 3-10 sugar molecules and the two most common are some of the complex carbohydrates found in dried beans, peas and lentils[1].

Raffinose is an oligosaccharide made from 3 sugar molecules: galactose-glucose-fructose and stachyose is an oligosaccharide made from 4 sugar molecules: galactose-galactose-glucose-fructose.

The body can’t break down either raffinose or stachyose, but this is done by the bacteria in the intestine.

Polysaccharides

Polysaccharides are made up of hundreds or thousands of sugar molecules linked together. When those sugar molecules are only glucose, the polysaccharide is called “starch”.

Some polysaccharides form long straight chains while others are branched like a tree. These structural difference affect how these carbohydrates behave when they’re heated or put in water.

The way the monosaccharides are linked together makes the polysaccharides either digestible as in starch, or indigestible as in fiber.

Polysaccharides found in plant foods such as fiber, cellulose, hemicellulose, gums and mucilages (such as psyllium) are indigestible by the body so won’t be covered in this article, but it should be noted that they can slow down the absorption of digestible carbohydrate.

Starch

Starches are long chains of glucose molecules strung together like beads on a string and are the ones illustrated in Dr. Dikeman’s illustration, above.

Starches are found in grains such as wheat, corn, rice, oats, millet and barley as well as in legumes such as peas, beans and lentils* and tubers such as potatoes, yams and cassava.

*Recall as mentioned above that peas, beans and lentils also have the complex carbohydrates called oligosaccharides which are not broken down by the body, but by the bacteria of the gut.

There are two types of starches; the long unbranched chains called amylose and the long branched chain ones call amylopectin. What is important in this context is that the long branched chain starches called amylopectin are more easily digested.

The body digests most starches very easily, although those with a high percentage of amylopectin (such as cornstarch) are digested much more easily than those with a high amount of amylose, such as wheat starch [1].

Since starches are just glucose molecules linked together and they are easily broken down to individual glucose molecules, starches can quickly affect the blood sugar of those who are pre-diabetic or have Diabetes.

That is the “point” behind Dr. Dikeman’s illustration, above which I have modified slightly, below.

adapted from graphic by RD Dikeman by Joy Y. Kiddie, MSc, RD

Those who are Diabetic (or pre-diabetic) already have challenges with their blood glucose (“blood sugar”), so does eating foods that are nothing more than long strings of glucose such as starches really make sense?

Note: While the fiber content of whole grain pasta will slow down its digestion compared to refined pasta, it is still long strings of glucose molecules. Think of whole wheat pasta as a string of pearls with in addition to the pearls, in this case fiber.

Digestion of Carbohydrates

Carbohydrate digestion begins in the mouth where an enzyme in saliva called amylase breaks starch down into shorter polysaccharides and maltose.

The acidity of the stomach temporarily stops the effect of the salivary amylase, but the digestion of carbohydrate starts up again in the small intestine where most carbohydrate digestion takes place. Digestion of carbohydrates begins again when the pancreas secretes pancreatic amylase into the small intestine.

In the small intestine, starch is broken down in to many, many individual units of the disaccharide maltose, which are simply two glucose molecules linked together. Then, enzymes located to the brush border of the small intestine break the alpha bond which holds the two glucose molecules together.

It’s easy to understand how starch, which is simply long chains of glucose molecules strung together are so easily broken down when digestion already starts in the mouth and is completed in the small intestine where the disaccharide (maltose) is broken down into 2 glucose molecules.

In the small intestine, other enzymes split other disaccharides into monosaccharides; so for example, the enzyme sucrase splits the disaccharide sucrose into glucose and fructose and the enzyme lactase splits the disaccharide lactose into glucose and galactose.  Note that these other disaccharides are only 1/2 glucose.

Absorption of Carbohydrates

Monosaccharides are absorbed into the mucosal cells of the small intestine and travel to the liver, where galactose and fructose are converted to glucose and the glucose is stored in the liver as glycogen.

Glycogen is long, highly branched chains of glucose molecules (similar to amylopectin, but much more highly branched). When needed, the liver can break down glycogen into glucose at a rate of 100 mg to 150 mg of glucose per minute for up to 12 hours [2].

When glycogen stores of the liver are already full, the glucose from the broken down carbohydrate with the help of the hormone insulin converts the excess glucose into fat and sends to other parts of the body to be stored in adipose tissue.

Carbohydrate-based Foods in the Diet

As covered in previous articles including this one , there is NO requirement for people to eat carbohydrate-based food” provided that adequate amounts of protein and fat are consumed”[3] which are used to provide essential glucose for the brain via gluconeogenesis. This does not mean that I recommend people don’t eat any carbohydrate-based food!

Which carbohydrate-based food people are able to eat and in what quantity without it affecting their blood sugar to any large degree varies considerably from person to person[4], whether or not they are Diabetic.  For those who already have Type 2 Diabetes or are pre-diabetic, a personalized nutrition approach is needed.  This is often called “eating to your meter“; testing a specific quantity of a food by itself, to see how your blood sugar responds. 

Based on research, some people with Type 2 Diabetes can do well eating certain types of legumes (pulses) including black beans, white navy beans, pinto beans, red and white kidney beans, chickpeas and fava beans [5] which is helpful for those who follow a plant-based vegetarian diet. Once people have lowered their HbA1C and fasting blood glucose levels and achieved remission of Type 2 Diabetes symptoms, I work can work with them in determining which foods they can re-introduce into their diet and in what quantities and how often, so as not to adversely impact their blood sugar. Some do better than others.

Over the last 4 years of my clinical practice, I have found that many people with pre-diabetes or Type 2 Diabetes can often manage their blood glucose well while including small servings (1/2 cup / 125 ml) of whole-food starchy vegetables such as winter squash (butternut, acorn, kobacha, etc.), as well as small servings of other starchy whole-food vegetables such as orange or purple yam, or peas. For those eating a moderately-low level of carbs (non-ketogenic) or want to keep eating these foods, I encourage them to choose these more often over starch-based foods such as pasta, rice and bread.

That doesn’t mean that people with Type 2 Diabetes shouldn’t ever eat whole, unmilled brown rice or quinoa but that avoiding refined starches such as white bread, pasta and rice is best preferable.

I hope that you found this article helpful to understand what complex carbohydrates are, and why certain types of complex carbs are more of a challenge to those with Type 2 Diabetes or pre-diabetes.

If you have questions about how I can help you eat in a way to lower your blood sugar levels, please send me a note through the Contact Me form above and for information about the types of services I offer, please have a look under the Services tab or in the Shop.

To your good health,

Joy

You can follow me on:

Twitter: https://twitter.com/lchfRD
Facebook: https://www.facebook.com/lchfRD/
Instagram: https://www.instagram.com/lchf_rd

Copyright ©2019 The LCHF-Dietitian (a division of BetterByDesign Nutrition Ltd.)

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the “content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

References

  1. Chapter 4, Carbohydrates: Simple sugars and Complex Chains, http://samples.jbpub.com/9781284064650/9781284086379_CH04_Disco.pdf
  2. Rappaport B, Metabolic factors limiting performance in marathon runners. PLoS Comput Biol. 2010; 6(10). doi: 10.1371/journal.pebi.1000960
  3. National Academies Press, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids (2005), Chapter 6 Dietary Carbohydrates: Sugars and Starches”, pages 265-275
  4. Zeevi D, Korem T, Zmora N, et al. Personalized Nutrition by Prediction of Glycemic Responses. Cell. 2015 Nov 19;163(5):1079-1094.
  5. Sievenpiper, J.L., Kendall, C.W.C., Esfahani, A. et al. Effect of non-oil-seed pulses on glycaemic control: a systematic review and meta-analysis of randomised controlled experimental trials in people with and without diabetes. Diabetologia (2009) 52: 1479.

Carbohydrates are Not Evil

Much of the discussion about nutrition these days on social media seems to take an “all-or-nothing” stance on carbohydrates.  On one hand there are those who promote a plant-based diet that necessarily comes with a large amount of carbohydrate as grains, legumes (pulses) such as beans and lentils as well as carbohydrate-containing vegetables and fruit, and on the other hand there are those who eschew anything with the remotest amount of carbohydrate.

In politics, there are left-leaning ‘liberals’ and right-leaning ‘conservatives’, as well as those that hold a moderate position called “centrists”.

I am a centrist when it comes to my position regarding carbohydrates. In this article, I will elaborate on the following;

  1. Carbs are not evil or single-handedly responsible for the obesity epidemic or metabolic diseases. If that were the case, then the traditional diets of much of Asia and West Africa would have resulted in obesity and diabetes and they did not. It is the degree of processing of the carbohydrate-based foods that impacts the blood glucose and blood insulin response of carbohydrate-containing foods.
  2. Carbohydrate-based foods combined with fat in the same food ‘hijack’ the reward center of our brains (striatum), resulting in over-consumption.
  3. Carbohydrates are not essential macronutrients.

Part 1 – Degree of Processing

Processing carbohydrate even in simple ways such as cooking or grinding means that more of the carbohydrate is available to the body to be digested. As pointed out in an earlier article which I will refer to throughout this section, when grains are cooked they become much more digestible – meaning that more of the nutrients in the grain is available to be absorbed. In the case of potatoes, there is double or triple the amount of energy (calories) available to the body when they are cooked versus when they are raw.

Mechanical processing, such pounding, grinding or pureeing are also forms of food processing which have an effect on how many nutrients are available to be digested. The nutrients available to the body when food is eaten raw and whole versus raw and pounded is significant.

Glucose Response – based on the amount of food processing

Mechanical processing of a food doesn’t change the amount of carbohydrate that is in it. That is, when 60 g of whole apple are compared with 60 g of pureed apple or 60 g of juiced apple, there are the same amount of carbohydrates in each and the Glycemic Index of these are similar, however when these foods are eaten the blood glucose response 90 minutes later is significantly different. As outlined in the earlier article, in healthy individuals, blood glucose level goes very high with the juiced apple and in response to the release of insulin, blood glucose then goes very low, below baseline. The response that we see with the juiced apple in healthy individuals is typical of what is seen with other forms of ultra-processed carbohydrates.

This is why it is preferable for metabolically healthy people to eat carbohydrate-based foods as whole, unprocessed foods with a minimum of disruption to the cell structure.

Insulin Response with Mechanical Processing

When healthy individuals eat grain-based meals, the plasma insulin response is inversely related to the particle size of the grain.  That is whole, unprocessed grain releases less insulin than the same amount of cracked grain, which is still less than the same amount of course flour. The highest amount of insulin is released in response to eating the same amount of fine flour.

This increased insulin response of eating grains that are highly processed can drive chronic hyperinsulinemia (chronically high levels of insulin) that eventually results in insulin resistance; the beginning of the metabolic disease process.

It is for this reason that for metabolically healthy individuals, eating whole, unrefined grains is recommended.

Effect or Lack of Effect of Fiber

It is the lack of disruption to the cell structure of the grain that limits the insulin response and not the fiber content that makes the difference.

As mentioned in the earlier article (link above), studies have been done with bread where the fiber was added back in (such as in so-called “whole wheat bread” which is essentially white bread with added bran) and the insulin response was the same as with white bread, so it is not the amount of fiber in the grain that makes the difference, but the lack of disruption to the grain structure itself. I find it helpful to think of it in terms of ‘the fiber that counts is that which is part of the whole, undisrupted grain’.  (Note: it is for this reason that I only factor “net carbs” for food whose fiber is in this undisrupted form. For all other products where fiber is added, I don’t deduct the fiber).

The disruption of the structure of the grain also has an adverse effect on GIP response (an incretin hormone released from the K-cells high up in the intestine that triggers the release of insulin). Bread made with flour (as opposed to whole, intact grains) results in a much larger and earlier plasma GIP response, which in turn results in a higher and earlier insulin response, than bread made with whole kernel grains, such as artisanal rye or wheat breads.

In metabolically healthy individuals, the eating of whole, intact minimally processed carbohydrate-containing food is preferable, as opposed to eating processed carbohydrate-containing foods (be it grains or fruit) with significant disruption to the cell structure.

Part II – Carbohydrate and Fat Combined

In nature, there are very few foods in the human diet that contain a combination of both carbohydrate and fat in substantial quantities. Human breast milk is one of those few natural foods, along with some nuts and seeds. When humans began drinking the milk of other mammals such as goats, sheep and cows, milk became one of those foods.

Also as outlined in a previous article foods with both fat and carbs together result in much more dopamine being released from the reward-center of our brain, called the striatum. Dopamine is the same neurotransmitter that is released during sex and that is involved in the addictive “runner’s high” familiar to athletes so this is a very powerful neurotransmitter.

It is believed that there are separate areas of the brain that evaluate carb-based foods and fat-based foods but when carbs and fat appear in the same food together, this results in what the researchers called a “supra-additive effect“. That is, both areas of the brain get activated at the same time, resulting in much more dopamine being released from the striatum and a much bigger feeling of “reward” being produced. This combination of carbs and fat in the same food is why we find foods such as French fries, donuts and potato chips irresistible and this powerful reward-system is why we’ll  choose French fries over baked potato and why we have no difficulty wolfing back a few donuts, even when we’ve just eaten a meal.

This “supra-additive effect” on the pleasure center of our brain along with the fact that more insulin is released when both carbs and fat are eaten together helps explain the roots of the current obesity epidemic and the metabolic diseases such as Type 2 Diabetes that go along with it. The high rates of obesity seen more recently in places like China (as covered in this article) are due to the adoption of Western eating habits (refined, processed foods) that are notoriously high in both carbohydrates and fat.

When foods that are rich sources of carbohydrate are eaten it is best that foods that are also rich sources of fat are not eaten at the same time in order to avoid this supra-additive effect.

I do not believe that carbohydrate-based foods in and by themselves in metabolically healthy individuals are the underlying cause of obesity and metabolic disease. I believe that it is the (1) consumption of carbohydrate-based foods that have undergone some kind of food processing (grinding, milling, pureeing, etc) that has disrupted their cell structure and (2) the consumption of foods that combine both carbohydrate and fat in the same food that have driven both.

Part III – Carbohydrates are Not Essential Macronutrients

With all the arguing about eating more carbs or less carbs, it needs to be emphasized that carbohydrates are not essential nutrients. Yes, the body needs a certain amount of glucose for the brain, but the body can make this glucose from protein and fat through a process called gluconeogenesis.

This is not simply my opinion, but is stated by the Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids (2005) on page 275;

The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed. 

That is, there is no essential need for dietary carbohydrate provided there are adequate amounts of protein and fat provided in the diet.

The Recommended Dietary Allowance (RDA) for carbohydrate is set at 130 g / carbohydrate per day based on the average minimum amount of glucose utilized by the brain— however the body can manufacture this glucose from protein or fat. A well-designed low carbohydrate diet provides sufficient amounts of fat and  protein such that the body can manufacture the glucose it needs.

Carbohydrate – to eat or not to eat

For Healthy Individuals

For those who are healthy and metabolically flexible, consumption of whole, unprocessed carbohydrate-containing foods such as whole grains, tubers, starchy vegetables such as peas, squash and corn and whole fruit are of no concern. Due to the ‘supra-additive’ effect of fats with carbohydrate, I recommend that when eating carbohydrate-based foods, to avoid foods that are a rich source of fat.

For Metabolically Unhealthy Individuals

As mentioned in the two previous articles related to the new Canada Food Guide (here and here), 88% of Americans are already metabolically unwell, with presumably a large percentage of Canadians as well.

That is, only 12% have metabolic health defined as;

  1. Waist Circumference: < 102 cm (40 inches) for men and 88 cm (34.5 inches) in women
  2. Systolic Blood Pressure: < 120 mmHG
  3. Diastolic Blood Pressure: < 80 mmHG
  4. Glucose: < 5.5 mmol/L (100 mg/dL)
  5. HbA1c: < 5.7%
  6. Triglycerides: < 1.7 mmol/l (< 150 mg/dL)
  7. HDL cholesterol: ≥ 1.00 mmol/L (≥40 mg/dL) in men and ≥ 1.30 mmol/L (50 mg/dl) in women

For the large majority who are metabolically unhealthy, knowing which carbohydrate-based food raise one’s blood glucose levels is important. Even if lab tests show one’s fasting blood glucose is still normal, blood glucose levels after eating carbohydrate may be quite abnormal, and even more significantly insulin levels may be as well. You can read more about that here. As mentioned previously in this article, these high insulin levels are what drives metabolic disease by driving insulin resistance.

Eating a low carbohydrate diet can be very helpful to lower blood glucose response and lower chronically high levels of insulin. Which carbohydrates can be tolerated and in what quantities varies considerably between people, but is easy to determine and I help people do this.

For those that already have Type 2 Diabetes, reducing carbohydrate intake for a considerable length of time will enable them to reduce their overall blood glucose and insulin response, which will help them reverse the symptoms of Diabetes as well as other metabolic diseases that often go along with it, such as high blood pressure and high triglycerides. In time, some carbohydrates may be able to be eaten again however the amount and type will vary between individuals.

Final Thoughts…

Carbohydrates aren’t “evil”.  In and by themselves, they don’t result in obesity or metabolic disease. It is the amount of food processing that carbohydrate-containing foods have undergone that results in cell-wall disruption that will determine how much of a glucose- or insulin-response they will cause. In metabolically healthy people, eating minimally processed whole grains, starchy vegetables and fruit without a source of fat is fine.

For those who are metabolically unhealthy, especially those who have a measurably abnormal glucose- or insulin-response, the amount of carbohydrate that can be tolerated is individual and will need to be determined.

For those who have Type 2 Diabetes and follow a low carbohydrate diet to reduce the symptoms of high blood sugar or metabolic diseases that often go along with it, eating the amount of tolerated carbohydrates as minimally processed ones, without a source of fat is also best.

There is no “one size fits all” diet that is suitable for everyone.

For metabolically healthy individuals, following the new Canada Food Guide and selecting carbohydrate sources using the above principles can provide people with a healthy diet. For those that are already metabolically unhealthy, I can help design a Meal Plan that will meet your energy and nutrient needs and that provides the amount of carbohydrate that you can tolerate. If you would like more information, please send me a note using the Contact Me form, above and I’ll be happy to reply soon.

To your good health!

Joy

You can follow me at:

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Copyright ©2019 The LCHF-Dietitian (a division of BetterByDesign Nutrition Ltd.)

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the “content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

New Canada Food Guide – carbohydrate estimate of the sample plate

There has been some discussion on Twitter that the macronutrient estimated in the previous article of an average ~325-350 g of carbohydrate per day based on a 2000 kcal per day diet for the new Canada Food Guide was “too high”, so in the interest of determining whether it was accurate, I’ve evaluated the carbohydrate content of the illustrated plate.

Actual Number, Standard Cup Measure and Scale of Reference

Since no portion sizes are provided with the new guide, both scale of reference or when available, the actual number of items was used.

The actual number of chickpeas, kidney beans, nuts and seeds were used and determine in terms of the portions of a standard cup measure.

For items such as vegetables and fruit, actual portions were measured using a standard set of stainless steel measuring cups.

For any remaining quantities, since a quarter of an egg is featured on the illustration of a healthy plate and a large sized egg is the standard on which nutrient analysis is based and this is of a known size, I used the 1/4 of a large egg as the scale of reference for other items,when the actual number was not available.

Carbohydrate Content of the Protein Group

The protein group contributed~37 g of carbohydrate to the sample plate.

Carbohydrate content of the protein group on the sample plate

Carbohydrate Content of the Whole Grains Group

The whole grains group contributed more than~58 g of carbohydrate to the sample plate.

Carbohydrate content of the whole grains group on the sample plate

Carbohydrate Content of the Vegetable and Fruit Group

The vegetable and fruit group contributed more than~53 g of carbohydrate to the sample plate.

Carbohydrate content of the vegetable and fruit group on the sample plate

The sample plate used as an illustration for the new Canada Food Guide has close to 150 g  of carbohydrate on it— and this is for only one meal. The carbohydrate content of lunch and dinner (the two generally mixed meals of the day) already totals as much as 300 g of carbohydrate — and there’s still breakfast to add! Whether it’s a couple of whole grain toast (30 g carbs), 2 tbsp unsweetened nut butter (6 g carbs) or some whole grain cereal (30 g carbs) and 1/2 cup of low fat unsweetened yogurt (6 gm carbs), there’s another 42 g of carbs (plus the carbs for the milk or nut or soy milk to pour on the cereal); bringing the average for the three meals alone to 337+ g of carbs which is exactly what it was estimated as in the previous article — as between 325 – 350 g carbohydrate per day.

And this is just for 3  MEALS.

What about snacks?

Yes, snacks are mentioned  TWICE on the first page under the link for “eating habits” in the section on “how to make a meal plan and stick to it”;

Recommendations for meals and snacks

Assuming a person eats a “healthy whole grain” muffin without any dried fruit in it for coffee break in the morning (~50 g of carbs) and a single piece of fruit like an apple or orange mid-afternoon (15 g of carbs), these add another 65 g of carbohydrate to this day, bringing the average total to over 400 g of carbohydrate for one day.

UPDATE (January 26, 2019) Given the sample plate is there to demonstrate proportions, not portions — looking at the grain group alone, the proportion of grain is 1/4 of the dietary intake. Based on a 2000 kcal/day diet, that’s 500 calories per day / ~125 g of carbohydrate from the grain group alone. Add in the carbohydrate from the largely plant-based protein group, that’s another ~100 g carbohydrate per day, on average. Since half the plate should be vegetables and fruit and both starchy vegetables such as squash, yam, potato, peas and corn contain 15 g of carbohydrate per half cup, as does the same amount as fruit, it is reasonable to assume that on average, half of the vegetable servings will be comprised of a mixture of starchy vegetables — along with the fruit servings and the other quarter of the plate of non-starchy vegetables. That is, 1/4 of the vegetable and fruit side of the plate will be carbohydrate-containing, adding another ~125 g of carbohydrate per day to the diet. Of course, there will be days where people will eat lower carbohydrate grains like quinoa and lower carbohydrate plant-based protein such as tofu, but equally there will be days where vegetable servings are starchy ones such as peas and corn along with plant-based proteins that are higher in carbohydrate, such as legumes like kidney beans. So, the numbers above are averages.  Whether one uses the portions on sample plate as a basis for estimating the carbohydrate content or uses the proportion of the diet that is carbohydrate, the results fall in the same range of an average of 325 – 350 g carbohydrate per day, based on only 3 meals (without snacks).

Real Life Meals

Despite there being no “portion sizes” in the new Canada Food Guide, some insist that a “serving of pasta is 1/2 cup” because that is what is illustrated on the sample plate. Okay, let’s go with that for the sake of argument.

If a person ate twice that amount of pasta (instead of also eating some wild rice or rice or bread, for example), this is what the size of that portion would look like (of course it would be “whole grain”):

1 cup of cooked pasta – size of a tennis ball

I’ve been in private practice a long time and in my experience only children and women who are portion restricting eat pasta in amount the size of a tennis ball.  More than 90% of my clients report eating servings of pasta that are significantly larger than that. In fact, the usual ‘smaller-sized’ servings are about a cup and a half when eaten along with salad or a cooked vegetable (bigger if eaten alone). What does a cup and a half of pasta look like? It looks like this;

1 1/2 cups of whole grain pasta

…and this amount of pasta without sauce has 45 g of carbohydrate in it — which is still less than the 53 g of carbs illustrated in the Canada Food Guide sample plate.

Naturally, no one is expected to eat exactly like the “sample meal”, but whether one eats their “whole grains” as all brown rice, wild rice, Bulgar wheat or something else, 1/4 of the plate all have the same amount of carbohydrate per 1/2 cup serving as pasta.

Add to the pasta the vegetables and fruits above on the sample plate (or corresponding assortment of a mix of starchy, non-starchy vegetables and fruit) and that adds up to 100 g of carbohydrate …and we still haven’t added any protein into the meal, yet.

Add another 37 g of carbohydrate for an assortment of legumes, nuts and seeds as well as a bit of meat and “low fat” cheese for the pasta sauce (because after all, we are encouraged to eat animal protein “less often”) and that totals more than 135 g of carbs for just this one “real life” meal. Eat a meal like the one in the sample illustrations, it adds up to 150 g of carbs!

The question I’ve been asked is if it is “healthy whole grain”, then what’s the concern?

For metabolically healthy adults, none. For metabolically healthy adults, the new Canada Food Guide is a huge improvement from it’s predecessor! It eliminates refined carbs, sugary drinks including fruit juice and encourages eating whole foods, cooked at home as much as possible.

The problem is, most adults are not metabolically healthy.

Majority of Adults Metabolically Unhealthy

As mentioned in the previous article research indicates that as many as 88% of Americans[1] are already metabolically unwell, with presumably a large percentage of Canadians as well. That is, only 12% of the adult population would be considered metabolically healthy [1]”.

Metabolic Health is defined as [1];

  1. Waist Circumference: < 102 cm (40 inches) for men and 88 cm (34.5 inches) in women
  2. Systolic Blood Pressure: < 120 mmHG
  3. Diastolic Blood Pressure: < 80 mmHG
  4. Glucose: < 5.5 mmol/L (100 mg/dL)
  5. HbA1c: < 5.7%
  6. Triglycerides: < 1.7 mmol/l (< 150 mg/dL)
  7. HDL cholesterol: ≥ 1.00 mmol/L (≥40 mg/dL) in men and ≥ 1.30 mmol/L (50 mg/dl) in women

Given the slightly lower rates of obesity in Canada (1 in 4) as in the United States (1 in 3), presumably there is a slightly lower percentage of Canadians who are metabolically unhealthy. For the sake of argument, let’s assume that there are TWICE as many metabolically healthy adults in Canada, which would mean that only slightly over 75% of adults are metabolically unhealthy.  Since Canada’s Food Guide is intended for a healthy population in order to reduce the risk of overweight and obesity as well as chronic diseases manifest as the markers above, that means that the new Canada Food Guide — as beautiful as it is, is only appropriate for ~1/4 of the adult population.

For the other 75% of adults that are presumably metabolically unwell, a diet that provides 342 g of carbohydrate per day for meals alone (based on a 2000 kcal per day diet) and as much as 400 g of carbohydrate per day with 2 “healthy” snacks is not going to address the large percentage of adults who are already demonstrating symptoms of being carbohydrate intolerant.

Carbohydrate Intolerance

As outlined in detail in a previous article, based on a large-scale 2016 study that looked at the blood glucose response and circulating insulin responses from 7800 adults during a 5-hour Oral Glucose Tolerance Test, 53% had normal glucose tolerance at 2 hours but of these people, 75% had  abnormal blood sugar results between 30 minutes and 60 minutes  demonstrating that they were already hyperinsulinemic, although it went undetected on standard assessors that only look at glucose and insulin responses at baseline (fasting) and at 2 hours.

These people are already exhibiting symptoms of not tolerating a normal carbohydrate load of 100 g.

How does it make sense to encourage adults that already have abnormal glucose response to eat 150 g of carbohydrate per meal when these people already have an impaired first-phase insulin response? How will eating “whole grains” and the “added fiber from plant-based proteins” improve their first-phase insulin response (which likely results from dysfunction in the release of the incretin hormone GIP (Glucose-dependent Insulinotropic Polypeptide) from the K-cells?

For these people, continuing to eat a diet high in carbohydrate, irrespective of the amount of fiber or the glycemic load will not restore their insulin response, and in time is likely to make it worse. This is my concern.

Canada Food Guide is for a healthy population to avoid the risk of chronic disease and based on these statistics most adults are not metabolically healthy.

Final Thoughts…

For the ~1/4 of adults that are metabolically healthy, I think the new Canada Food Guide is beautiful and focuses on real, whole food, preparing food at home, avoiding refined grains and avoiding high sugar beverages such as fruit juice (formerly seen as “healthy”).

For the high percentage of adults that are already metabolically unwell and who already demonstrate abnormal glucose responses, I don’t see that advising them to eat a diet that is between 325-350 g of carbohydrate per day (meals without snacks) helps them to avoid the progression to Type 2 Diabetes.

If you are part of the majority of Canadians that are already struggling with overweight and/or being metabolically unwell and would like to know more about how I may be able to help you achieve a healthy body weight and restore metabolic markers then please send me a note using the Contact Me form, on the tab above.

To your good health!

Joy

You can follow me at:

         https://twitter.com/lchfRD

          https://www.facebook.com/lchfRD/

           https://plus.google.com/+JoyYKiddieMScRD

https://www.instagram.com/lchf_rd

References

  1. Araújo J, Cai J, Stevens J. Prevalence of Optimal Metabolic Health in American Adults: National Health and Nutrition Examination Survey 2009–2016. Metabolic Syndrome and Related Disorders Vol 20, No. 20, pg 1-7, DOI: 10.1089/met.2018.0105
  2. Crofts, C., et al., Identifying hyperinsulinaemia in the absence of impaired glucose tolerance: An examination of the Kraft database. Diabetes Res Clin Pract, 2016. 118: p. 50-7.

Copyright ©2019 The LCHF-Dietitian (a division of BetterByDesign Nutrition Ltd.)

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the “content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

Why Carbs and Fat Together are Irresistible

A study that is due to be published on July 3, 2018 in the scientific journal Cell Metabolism is the first to demonstrate that compared to foods high in carbs or fat, foods with both carbs and fats together result in much more dopamine being released from the striatum, which is the reward-center of our brain [1]. Dopamine is the same neurotransmitter that is released during sex and that is involved in the addictive “runner’s high” familiar to athletes. This is one powerful neurotransmitter!

It is thought that there are separate areas of the brain that evaluate carb-based foods and fat-based foods and both are involved in the release of dopamine, but when carbs and fat appear in the same food together, this results in what the researchers called a “supra-additive effect”. That is, both areas of the brain get activated at the same time, resulting in much more dopamine being released and a much bigger feeling of “reward” being produced.

This combination of carbs and fat in the same food is why we find foods such as French fries, donuts and potato chips irresistible.

In fact, the study found that people were willing to pay more for foods that combine both carbs and fat than for foods that were only high in carbs but not fat such as candy, or only high in fat but not carbs, such as cheese.

This powerful reward-system involving dopamine is why we will choose the fries over the baked potato and why we have no difficulty wolfing back a few donuts, even when we’ve just eaten a meal.

 

This “supra-additive effect” on the pleasure center of our brain, along with the fact that more insulin is released when both carbs and fat are eaten together[2] may help explain the roots of the current obesity epidemic and the metabolic diseases such as Type 2 Diabetes that go along with it.

Carbohydrate intake was high in the early 1900s and gradually decreased until about 1954, leveled off, then began to increase again[3]. What caused that to occur? At that time, ultra-refined carbohydrates began appearing in the market and these by their very nature were devoid of the whole, unprocessed grain that slows the release of insulin [3] (for more information on the mechanism, please see this article).  Excess release of insulin made worse by the constant eating of ultra-refined carbohydrate foods underlies the process of how insulin resistance develops and in time, how Type 2 Diabetes develops [3].

The early 1950’s was also when the “diet-heart hypothesis” proposed by Ancel Keys took root, along with the recommendation that Americans (and later, Canadians) reduce their consumption of saturated fat (more in this article).  With the recommendation to decrease saturated fat was the necessity to create fats to replace them, which is when and why both soybean oil and later, canola oil were created (see this article for more information). These industrial seed oils began to replace natural fats such as butter, lard and tallow in home and restaurant cooking, frying and baking.

With the creation of “polyunsaturated vegetable oils”, French fries were now a healthy food – after all, they were vegetables fried in “healthy polyunsaturated fat”. What could possibly go wrong?

This new study provides the missing link as to the mechanism by which the “perfect storm” was created. That “perfect storm” was the simultaneous appearance in the late 1950s and early 1960s of ultra-refined carbohydrates and industrial seed oils (promoted as “heart healthy” by the American and Canadian Dietary Guidelines) that literally hijacked the reward system of our brain!

Is there little wonder why rates of overweight and obesity began rising at in the early 1960s and have continued to rise dramatically ever since?

As far as our brains are concerned, French fries are much more desirable than a baked potato and donuts and pastry much more desirable than toast because they literally make us feel good!  Eating French fries and pastry results in considerably more dopamine being released than eating baked potato or plain toast. Eating these foods produce something comparable to a “runner’s high” in people that have never run a block or have even gotten off the couch!

While discovery of the dopamine-centered mechanism is new to this study, the food industry has known for some time that processed foods containing both carbohydrate and fat will result in people coming back and buying more and more of their product. Carbs and fat is why Lays® chips could boast “betcha can’t eat just one!“, but it’s not just Lays®. This combination of carbs and fat is in all processed foods; from so-called “junk food” such as chips and Cheezies® to foods that are perceived as “healthy foods”, such as granola bars and commercial peanut butter.

Carbs and fats together are the essence of “fast food” – from Big Macs® dripping with cheese and mayo sandwiched between several buns, to French fries of all types, super-sized or not.  People may joke about “junk food being addictive”, however understanding the “supra-additive” effect of carbohydrate combined with fat makes these foods as addictive to our brains as a “runner’s high” is to an athlete, or what makes people seek out sex. Addictive? Maybe not in the truest sense of the word except in cases of food addiction, but certainly in the rest of us there is a powerful draw to want to eat them.

Knowing and understanding this mechanism is of no small consequence! It should inform our food choices.

We need to be aware of foods that we eat that “hijack” our appetites. They could be “healthy foods” like cashews that are both high in fat and high in carbohydrate.  Given what we know about the triggering of the reward system in the brain, should those of us with current or past weight problems have them around?

Another way this knowledge should inform our food choices is around the concept of “cheat days”.  People who see me seeking weight loss often ask me about whether they can have one day a week, or one day a month where they eat “cheat foods”.  Knowing the very potent chemically-mediated reward system involved with eating foods such as pizza or French fries or ice cream, do you think these are foods that are helpful to eat once a week or once a month? How much will eating those foods cause you to crave them later, after your “cheat day”? Is it worth it?

From a purely academic perspective, knowing the mechanism also helps explains why metabolically healthy people can lose weight either following a low-fat diet or a low-carb diet, because it is the combination of both carbs and fats that stimulate the reward centers.

Note: a low-carb approach is preferable for people who have have already become insulin resistant or diagnosed with Type 2 Diabetes because they are no longer able to handle more than small amounts of carbohydrate at a time without it significantly impacting their blood sugar (and insulin) levels.

So, knowing that eating carbs and fat together result in a huge release of dopamine and light up the reward-centers of our brain, how should we choose foods differently? What do we do if we eat carbs and fat at the same meal; does it matter which we eat first? Does how we process and prepare our carb-based foods make a difference on our blood sugar?

The answer to these questions is easy.  Yes, based in this study and many others, how we eat meals that have carbs, fat and protein (called “mixed meals”) matters and how quickly or slowly our blood sugar rises depends on when we eat them as well as how we process and prepare them.

This is where I can help.

I can explain in a very easy to understand way how to eat in such as ways as to minimize the impact on blood sugar, and beyond that, how to lower insulin release and insulin resistance which keeps blood sugar levels high.

If you would like information about my services or about having me design a Meal Plan for you, please send me a note using the “Contact Me” tab above and I will reply as shortly.

To our good health,

Joy

You can follow me at;

 https://twitter.com/lchfRD

  https://www.facebook.com/lchfRD/

References

  1. Di Feliceantonio et al., 2018, Supra-Additive Effects of Combining
    Fat and Carbohydrate on Food Reward, Cell Metabolism 28, 1–12
  2. Carrel, G., L. Egli, C. Tran, P. Schneiter, V. Giusti, D. D’Alessio, and L. Tappy. “Contributions of Fat and Protein to the Incretin Effect of a Mixed Meal.” American Journal of Clinical Nutrition 94, no. 4 (2011):997–1003.
  3. Gross, Lee S., Li Li, Earl S. Ford, and Simin Liu. “Increased Consumption of Refined Carbohydrates and the Epidemic of Type 2 Diabetes in the United States: An Ecologic Assessment.” The American Journal of Clinical Nutrition 79, no. 5 (2004): 774–779.
  4. O’Dea, K., Nestel, P.J., and Antonoff, L. “Physical Factors Influencing Postprandial Glucose and Insulin Responses to Starch” 33, no. 4 (April 1, 1980): 760–65. https://doi.org/10.1093/ajcn/33.4.760.

Copyright ©2018 The LCHF-Dietitian (a division of BetterByDesign Nutrition Ltd.)

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the “content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

How Much Carbohydrate is Essential in the Diet?

INTRODUCTION: I was asked a question recently on social media as to what is our body’s essential daily requirement for carbohydrate. This is a very good question – so much so, that I decided to answer it in the form of a short article. If you are considering a low carb high fat lifestyle, this is important to understand.

Our body has an absolute requirement for specific essential nutrients; nutrients that we must take in our diet because we can’t synthesize them. What these nutrients are and how much we require depends on our age and stage of life, our gender and other factors and are listed in several volumes called the Dietary Reference Intakes (DRIs), published by National Academies Press.

There are Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids (2005), Dietary Reference Intakes for Calcium and Vitamin D (2011), Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids (2000), Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (1997), Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2005), Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (1998), Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc (2001).

In these texts are listed the essential amino acids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine) that must be supplied in the different kinds of protein that we eat.

These texts also establish that there are two essential fatty acids, linoleic (an omega 6 fat) and alpha-linolenic (an omega 3 fat) that can’t be synthesized by the body and must be obtained in the diet.

There are 13 essential vitamins (vitamin A, vitamin B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyrodoxine), B12 (cyanocobalamine), biotin, vitamin C (ascorbic acid), choline, vitamin D (cholecalciferol), vitamin E (tocopherol) and  folate) listed and essential minerals, including major minerals (calcium, phosphorus, potassium, sodium, chloride and magnesium) and minor minerals (chromium, cobalt, copper, fluorine, iodine, iron, manganese, molybdenum, selenium, silicon, sulfur and zinc).

But is there “essential carbohydrate”?

In Chapter 6 of the Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids (2005) is the chapter titled “Dietary Carbohydrates: Sugars and Starches” (pg. 265), which indicates that the  Recommended Dietary Allowance (RDA) for carbohydrate,  considered to be the average minimum amount of glucose needed by the brain, is set at 130 g / day for adults and children.

Recommended Dietary Allowance (RDA) for carbohydrate

It is important to note that the Recommended Dietary Allowance (RDA) for carbohydrate is at 130 g / day based on the average minimum amount of glucose needed by the brain – with no consideration that the body can manufacture this glucose from both FAT and PROTEIN.

Just 10 pages later, in the same chapter of the Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids (2005) it reads;

The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed. 

The lower limit of dietary carbohydrate

That is, there is no essential need for dietary carbohydrate, provided that “adequate amounts of protein and fat are consumed”.

The text goes on to say that there are traditional civilizations such as the Masai, the Greenland and Alaskan Inuit and Pampas indigenous people that survive on a “minimal amount of carbohydrate for extended periods of time with no apparent effect on health or longevity“, and that white people (Caucasians) eating an essentially carbohydrate-free diet resembling that of the Greenland natives were able to do so for a year, without issue.

That is, the minimum amount of dietary carbohydrate required is zero provided that adequate amounts of protein and fat are consumed. Phrased another way, the “minimum amount of glucose needed by the brain of 130 g / day is made by the body from protein and fat provided they are eaten in adequate amounts.

In the absence of carbohydrate, de novo synthesis of glucose

On the next page (pg. 276) of the Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids (2005) it explains the process;

“In the absence of dietary carbohydrate, de novo synthesis of glucose requires amino acids derived from the hydrolysis of endogenous or dietary protein or glycerol derived from fat. Therefore, the marginal amount of carbohydrate required in the diet in an energy-balanced state is conditional and dependent upon the remaining composition of the diet.”

That is, even when minimal amounts of carbohydrate is eaten (not something I promote), the body will synthesize the glucose needed by the brain from the protein taken in through the diet (provided it is in adequate amounts) or from glycerol which is formed when fat is broken down. If the protein in the diet (exogenous protein) is inadequate however, the body’s own protein (endogenous protein) will be used.

So, no, there isn’t any “essential carbohydrate” requirement.

Even when a person is completely fasting (religious reasons, medically supervised, etc.) the 130 g / day of glucose needed by the brain is made from endogenous protein and fat.

When people are “fasting” the 12 hour period from the end of supper the night before until breakfast (“break the fast”) the next day, their brain is supplied with essential glucose! Otherwise, sleeping could be dangerous.

In previous articles reviewing long-term studies of low carbohydrate diets, safety and efficacy has been established with intakes as low as 20 gm of carbs for 12 weeks and 35 gm of carbohydrate per day for extended periods of time, provided adequate protein and fat is eaten.

I am of the opinion that in order to have a diet with the essential vitaminsminerals, amino acids and fatty acids, that a wide range of healthy foods with some carbohydrate content is required.  I encourage people to consume low carb fruit and dairy products and nuts and seeds, along with a wide range of meat, fish and poultry, eggs and even tofu, if desired. I design each person’s Meal Plan to meet their individual requirements, lifestyle as well as the foods they like and take into consideration whether they like to cook or prefer meals with the minimum of preparation required.

Have questions?

Please send me a note using the “Contact Me” located on the tab above and I will reply soon.

To our good health,

Joy

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Note: Everyone’s results following a LCHF lifestyle will differ as there is no one-size-fits-all approach and everybody’s nutritional needs and health status is different. If you want to adopt this kind of lifestyle, please discuss it with your doctor, first.

Copyright ©2017 The LCHF-Dietitian (a division of BetterByDesign Nutrition Ltd.) 

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the “content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.