Part II- Understanding Low Carb High Fat – the solution

INTRODUCTION – In Part I of this two-part series, I explained how the current dietary recommendations and popular beliefs about weight gain have inadvertently contributed to many of the health problems we now face.  If you haven’t yet read the first part, you can read it here and then follow the link back to continue reading this article.

In this post, I point to some previously written articles posted on this site to explain what a Low Carb High Fat style of eating is and how it serves as a solution to the problems outlined in the previous article.

Part II – Understanding Low Carb High Fat – the solution

Low Carb High Healthy Fat – food categories (acknowledgements: adapted from an illustration by Dr. Ted Naiman)

What exactly is a Low Carb High Fat Diet?  This article explains the fundamentals information people want to know about which food categories they can eat such as non-starchy vegetables, plant fat, low sugar fruit, meat fish poultry and seafood, animal fat and unsweetened beverages).

There is also a simple illustration of the food categories in a low carb lifestyle, indicating the types of food in each category. This dispels the myth that eating LCHF is in anyway a ‘restricted diet’.

This post also explains what macronutrients are and what the ratios of protein, fat and carbohydrate are on a LCHF diet.  This article is a basic primer to the Low Carb High Fat lifestyle.

People sometimes refer to a “low carb diet” as if it were a single entity, but there are many types of low carb diets ranging from moderate low carb (130 g carbs) to ketogenic diets (5-10% net carbs).

This article titled American Diabetes Association Approves Low Carb Diets for Weight Loss explains the basics of a moderate low carb diets (130 g carbs) which is approved by the American Diabetic Association as a weight-loss option for Diabetics.

Since not all low carb diets are ketogenic diets, this article explains the basics of  What is a Ketogenic Diet and Why Eat Keto? It also explains the very important difference between ketosis (a normal, physiological state where our bodies run almost entirely on fat) and ketoacidosis (a serious medical state associated most commonly associated with Type 1 Diabetes).

Many people believe that saturated fat is “bad” for them but few realize that our bodies actually manufacture it. This article titled The “Skinny” on Fats explains the principles of fats while explaining the chemistry in simple terms that those with a non-science background can understand.  These ‘basics’ enable people to understand the controversy around saturated fat and to be able to talk about them with family members, friends, and their healthcare professionals.

People are used to thinking about food in terms of its ability to provide energy for their body but many don’t realize that their bodies can be fuelled by either carbohydrates or fat.  This article titled Humans – the perfect hybrid machine explains how in times past it was perfectly normal for us to experience a cycle of “feasting” and “fasting” – running on our own fat stores during the times between eating and how currently, we rarely are able to access our own fat stores, because of the constant supply of carbohydrate-rich food.

This article, titled Evidence for Remission of Type 2 Diabetes Symptoms using LCHF begins with a brief history of the Low Carb Diet and its role the primary approach to managing Diabetes prior to the discovery of insulin. It also talks about its role in managing seizure disorder and outlines how a Low Carb approach was central to the very first weight loss diet book written ~150 years ago.  It mentions the “Atkins Diet” which first came on the scene in the early 1970s and then introduces the research of Stephen Phinney (a medical doctor and PhD research scientist) and Jeff Volek, a Registered Dietitian with PhD whose work centers on using a low carb diet as a therapeutic tool for managing insulin resistance.  It presents the findings of Phinney and Volek’s most recent study which demonstrates that after 6 months following a low carb diet >75% of people in this study had HbA1c that was no longer in the Diabetic range (6.5%). It provides some evidence that yes, the symptoms of Type 2 Diabetes can to go into remission by following a Low Carb lifestyle.

Finally, the last article titled Are Low Carbohydrate Diets Safe and Effective provides compelling evidence from a two-year study which found that compared to a Mediterranean Diet and Low Fat diet, weight loss was greatest in those that followed a Low Carb diet. Of significance, subjects in in the LCHF group in this study also had lower fasting plasma glucose, lower HbA1C, significantly lower triglycerides, significantly higher HDL and lower C-reactive protein .

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Want to know how I can help you adopt a low carb lifestyle?

I provide LCHF in-person services to those in the Greater Vancouver BC area and LCHF Distance Consultation services to those living elsewhere in the province, or from other provinces and territories in Canada. Please have a look at the “My Services” tab above for a list of the LCHF services that I provide.

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Part I – Understanding Low Carb High Fat – the problem

INTRODUCTION – If you are one of those that is considering adopting a low carb high fat lifestyle and want to understand the reasons behind ‘why’, this post is for you. It will guide you through a handful of previously written articles on this site so that you’ll understand how the current dietary recommendations and popular beliefs about weight gain have inadvertently contributed to many of the health problems we now face.

As in anything, before considering a solution to a problem, we first need to understand the problem.

Part I – Understanding Low Carb High Fat – the problem

In 1977, the US and Canada changed their Dietary Recommendations  encouraging us to eat 45-65% of daily calories as carbohydrate and to limit all kinds of fat to 20-35%. Of relevance, in the early 1970s, prior to these changes only ~8% of men and ~12% of women were obese – and now almost 22% of men and 19% of women are obese.

The article titled Obesity Rates in Canada and Changes to Canada’s Food Guide will walk you through the changing recommendations of Canada’s Food Guide (CFG) over the years, as well as the corresponding and  simultaneous increase in the rates of overweight and obesity.

Unfortunately the dietary changes of 1977 have given us 40 years of data showing ever-increasing rates of obesity, overweight and Diabetes. It is quite literally an “epidemiological* experiment gone wrong”.  This article titled Canada’s Food Guide – an Epidemiological Experiment Gone Terribly Wrong will help you understand some of the shortcomings of the guide, as it stands now.

*Epidemiology is the study and analysis of the patterns, causes, and effects of health and disease in populations.

We’ve been told for years that the problem is that we “just need to eat less and exercise more“.  If it were really that simple then 4.7 million adults in Canada wouldn’t be classified as obese and more than 40% of men and 27% of women classified as overweight.  This article titled Why do we Gain Weight – the Myth of “Calories in, Calories out” will explain why this model doesn’t work.

We’ve also been told that people are overweight because “they lack self control” but this article titled Weight Gain as a Hormone Imbalance not a Calorie Imbalance explains how body weight is regulated automatically under the influence of hormones – hormones that signal us to eat and indicate when we are satiated. These hormones also signal our bodies to increase energy expenditure and when calories are restricted, they will slow energy expenditure. It’s not a matter of people “trying harder” but eating in such a way as to regulate these hormones.

In Part II titled Understanding Low Carb High Fat – the solution, I explain what a Low Carb High Fat style of eating is and how it serves as a solution to the health problems we now face.


Four Diets over Two Years – long term findings

INTRODUCTION: To date, there have been 3 long-term clinical trials (2 years) published over the past 10 years involving “low carb diets”.

The first long-term study that was presented in the previous article (which can be read here) clearly demonstrated that a low carb non–calorie-restricted diet was both safe and effective and produced the greatest weight loss, lower FBS and HbA1C, the most significantly lower TG and higher HDL and lower C-reactive protein (when compared with a low-fat calorie-restricted diet and a Mediterranean calorie-restricted diet).

In this, the second of the three long term studies, researchers looked at the effectiveness of four dietary interventions with different composition of fat, protein and carbohydrate – including one “low carb” diet..

Did this study demonstrate that a “low carb” diet was safe and effective to result in weight loss?

Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates


This study involved over 800 overweight and obese subjects, of which 40% were men. Subjects were between the ages of 30 and 70 years and had a Body Mass Index (BMI) of 25-40, where BMI is the weight in kilograms divided by the square of the height in meters.

BMI =25.0-29.9 is considered overweight
BMI = 30.0-34.9 is Class I obesity
BMI = 35.0-39.9 is Class II obesity
BMI ≥ 40.0 is Class III obesity

Major criteria for exclusion from this study were the presence of Diabetes or unstable cardiovascular disease, the use of medications that affect body    weight and insufficient motivation as assessed by interview and questionnaire.

Of the 811 subjects that began the study, at the end of two years, 645 subjects remained enrolled. Approximately 80% of the participants were white, 15% black, 4% Hispanic and the remaining 1% Asian.

The Four Diets – high/low fat, high/low protein

The 811 overweight adults were randomly assigned to one of four diets:

  1. Low Fat, Average Protein: fat: 20%, protein: 15%, carbohydrate: 65% (202 subjects)
  2. Low Fat, High Protein: fat: 20%, protein: 25%, carbohydrate: 55% (202 subjects)
  3. High Fat, Average Protein: fat: 40%, protein: 15%, carbohydrate: 45% (204 subjects)
  4. High Fat, High Protein: fat: 40%, protein: 25%, carbohydrate: 35% (201 subjects)
Two Diets were Low Fat but Two were not High-Fat Diets

The researchers stated that “two diets were low-fat and two were high-fat”, but it is important to note that none of the diets were “low carb high fat”/ ketogenic diets, which are ≥ 65% fat (not 40% fat). Two of the diets were higher in fat than the recommended dietary intake (in both the US and Canada).

Two Diets were Average Protein but not High Protein

The researchers said that “two diets were average protein and two were high protein” and while the ‘average protein intake’ in the US in 2008 was ~15%  (16.1% for men and 15.6% for women), diets such as two of the ones in this study that have only 25% protein are really at the very lowest range of what are considered high-protein diets – which normally contain between  27 – 68 % protein. Also important to note, a “low carb high fat”/ ketogenic diet usually has ~20% protein (considered ‘moderate protein’) and are not high protein diets.

Two Diets were High Carb and One Diet was Moderate Carb

The first and second dietary interventions would both be considered high carb, as they fall within the range of the dietary recommendations in both  Canada and the USA, 45-65% carbohydrate, with one being higher protein and one being average protein.

The third diet would be consider “moderate carb” according to Diabetes Canada’s standards, at 45 % carbohydrate, and higher fat and higher protein.

One Diet was Low Carb but not Ketogenic – and not Low Carb High Fat

The fourth diet could be considered ‘low-carb’ at 35% carbohydrate, but it is not a ketogenic diet, as the percent of carbohydrate is too high. A ketogenic diet has between 5-10% carbohydrate.  It was not a “high fat diet”, as the fat is only 40%, not ≥ 65% fat.

None of the dietary interventions in this study was 'low-carb high fat' or ketogenic, however one diet was "low carb".
Other Study Goals and Information

Other goals for all the dietary interventions were that the diets had;
– 8% or less of saturated fat
20 g or more of dietary fiber
150 mg or less of cholesterol per 1000 kcal

Each participant’s calories represented a deficit of 750 kcal per day
from baseline, as calculated from the person’s resting energy expenditure and activity level (which should have promoted a weight loss of ~ 1.5 pounds per week).

Blinding between the groups was maintained by the use of similar foods in each of the dietary interventions.

Staff as well as participants were taught that each diet adhered to principles of a “healthful diet” and that each had been recommended for “long-term weight loss”.

Group dietary counselling sessions were held once a week, 3 of every 4 weeks during the first 6 months and 2 of every 4 weeks from 6 months to 2 years; individual sessions were held every 8 weeks for the entire 2 years. Behavioral counseling was integrated into the group and individual sessions to promote adherence to the assigned dietary intervention.

Participants were instructed to record their food and beverage intake in a daily food diary and in a web-based self-monitoring tool that provided information on how closely their daily food intake met their dietary intervention’s goals for macronutrients and calories.

The goal for physical activity was 90 minutes of moderate exercise per week. Participation in exercise was monitored by questionnaire and by
the online self-monitoring tool.


Body weight and waist circumference were measured in the morning before breakfast on 2 days at baseline, 6 months, and 2 years, and on a single
day at 12 and 18 months.

Levels of serum lipids, glucose, insulin, and glycated hemoglobin (HbA1C) were measured via fasting blood samples, and 24-hour urine samples, and measurement of resting metabolic rate were obtained on 1 day, and blood-pressure measurement on 2 days, at baseline, 6 months and 2 years.


Weight loss and Waist Circumference

The amount of weight loss after 2 years was similar in participants assigned to a diet with 25% protein and those assigned to a diet with 15% protein.

Weight loss was the same in those assigned to a diet with 40% fat and those assigned to a diet with 20% fat.

There was no effect on weight loss of carbohydrate level through the target range of 35 to 65%.

Most of the weight loss occurred in the first 6 months, however 23% of the participants continued to lose weight from 6 months to 2 years.

The change in waist circumference did not differ significantly among the diet groups.

At 2 years, 31 to 37% of the participants had lost at least 5% of their initial body weight, 14 to 15% of the participants in each diet group had lost at least 10% of their initial weight, and 2 to 4% had lost 20 kg or more.

Risk Factors for Cardiovascular Disease and Diabetes

All the diets reduced risk factors for cardiovascular disease and Diabetes at 6 months and 2 years.

At 2 years, the two low-fat diets and the highest-carbohydrate diet decreased low-density lipoprotein (LDL) cholesterol levels more than did the high-fat diets or the lowest-carbohydrate diet, 5% vs 1%. And at 2 years, the highest carbohydrate decreased LDL more (6%) versus the lowest carbohydrate diet (1%).

The lowest-carbohydrate diet increased HDL cholesterol levels more (9%) compared with the highest-carbohydrate diet (6%).

All the diets decreased triglyceride (TG) levels similarly, by 12 to 17%.

All the diets except the one with the highest carbohydrate content decreased fasting serum insulin levels by 6 to 12% – and the decrease was larger with
the high-protein diet than with the average-protein diet (10% vs. 4%).

Blood pressure decreased from baseline by 1 to 2 mm Hg, with no significant differences among the groups.

The metabolic syndrome (defined as elevated fasting blood glucose, elevated blood pressure and abnormal triglycerides or cholesterol levels) was present in 32% of the participants at baseline, and the percentage at 2 years ranged from 19 to 22% in the four diet groups.

Diet Adherence

Mean reported intakes at 6 months and at 2 years were not at the target levels for macronutrients (fat, protein and carbohydrate). This limits the applicability of the data.

In the Low Fat, Average Protein group (fat: 20%, protein: 15%, carbohydrate: 65%), carbohydrate intake decreased from baseline by 12.8% and by 9.3% from baseline at 2 years and fat intake decreased from baseline by 11.8% at 6 months and 12.0% at two years. As it should have, protein intake hardly changed at 6 months (0.2%) but by 2 years it had increased by 2.1% to 19.6%.

In the Low Fat, High Protein group (fat: 20%, protein: 25%, carbohydrate: 55%) at 6 months carbohydrate intake decreased from baseline by 7.4% and at 2 years, it decreased from baseline by 6.8%. Protein intake increased from baseline by 3.9% at 2 years it had increased by 2.5% – but it is important to note that such a modest increase meant that this group did not consume a diet of 25% protein (but slightly less than 19% at 6 months and 17.5% at 2 years). Fat intake decreased from baseline by 11.8% at 6 months and 12.0% at two years.

In the High Fat, Average Protein group (fat: 40%, protein: 15% carbohydrate: 45%), at 6 months carbohydrate intake  decreased from baseline by 5.0% and at 2 years, it decreased from baseline by 2.4%. Protein intake hardly increased from baseline at 6 months (0.5%), but at 2 years it had increased from baseline by 2.1%. Fat intake in this group was supposed to have increased, but actually decreased from baseline by 3.8% at 6 months and decreased from baseline by 2.1% at two years.

In the High Fat, High Protein group (fat: 40%, protein: 25%, carbohydrate: 35%) – which was the only intervention that was “low carb”, at 6 months carbohydrate intake only decreased from baseline by 0.2% and at 2 years, it decreased from baseline by 0.4%. In fact, carbohydrate remained at ~ 43% the entire time. Protein intake was supposed to increase substantially, but only increased from baseline by 4.3%, and at 2 years it had had only increased from baseline by 3.4%. It is important to note that such a modest increase in protein meant that this group did not consume a diet of 25% protein but ~19.3 % at 6 months and ~18.4% at 2 years. Fat intake in this group was supposed to have increased, but actually decreased from baseline by 3.7% at 6 months and decreased from baseline by 3.4% at two years.

Neither of the "high protein" groups achieved anywhere near 25% of daily calories as protein.

Despite the intensive behavioral counseling in this study, participants did not achieve the goals for macronutrient intake of their assigned group and while some data in this study is helpful, the one group that was supposed to be “low carb” (high fat, high protein) was none of those!

Researcher’s Conclusion

The researchers concluded;

“we did not confirm previous findings that low-carbohydrate or high protein diets caused increased weight loss at 6 months”

High Protein Diet “Fail”

The reason that this study failed to confirm whether a high protein diet causes increased weight loss at 6 months is because neither of the two “high protein” diet groups in this study ate anywhere near the target protein level of 25%, but rather ate between 17.5%-19% protein,  which is remarkably close to the average protein intake of 15%  (16.1% for men and 15.6% for women). Subjects also ate no where near the lower limits of a “high protein” diet, which is 27-68% of daily calories as protein.

Low Carbohydrate Diet “Fail”

The reason that this study failed to confirm that a low carbohydrate diet causes increased weight loss is because the one group of the four diet interventions that was supposed to eat what the researchers defined as “low carb” (35% of calories as carbohydrate) ate ~43% of calories as carbohydrate the entire duration of the study. This as a moderate carb diet, not a low carb diet.

Final Thoughts

In this long term study, researchers set out to look at the effectiveness of four dietary interventions including a “low carb” diet group, however poor study design failed to produce even one of the four groups that ate low carb.


Sacks FM, Bray GA, Carey VJ et al, Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates, N Engl J Med. 2009 Feb 26;360(9):859-73