Chapter 18 | Fat Phobia

Oct 10, 2019

 

Click HERE to watch a replay of the Facebook LIVE discussion about this chapter. 

You Will Learn

  • Why low-fat diets became so popular. 
  • Saturated fat is not linked to heart disease. 
  • The fall of the low-fat diet. 
  • Good, neutral, and bad fats. 

 

About Dr. Fung, Author of The Obesity Code and The Diabetes Code

Dr. Jason Fung is a medical doctor, nephrologist by trade, who specializes in kidney disease, type 2 diabetes, and obesity. He acknowledged that traditional medicine wastes time and resources attempting to treat symptoms of disease, rather than the cause of disease. 

You can purchase The Obesity Code book HERE

 

Overview of the Book

Here is the outline of the book. This post covers chapter 18 in Part 5. 

Part 1: “The Epidemic,” explores the timeline of the obesity epidemic and the contribution of the patient’s family history. It highlights the underlying causes of obesity. 

Part 2: “The Calorie Deception,” reviews the current caloric theory in depth and highlights the shortcomings of the current understanding of obesity. 

Part 3: “A New Model of Obesity,” describes how hormones are involved in the development of obesity. These chapters explain the central role of insulin in regulating body weight and describe the vitally important role of insulin resistance. 

Part 4: “The Social Phenomenon of Obesity,” dives into childhood obesity and why obesity is associated with poverty. 

Part 5: “What’s Wrong with Our Diet?,” explores the role of fat, protein, and carbohydrates, the three macronutrients, in weight gain. In addition, it examines one of the main culprits in weight gain - fructose - and the effects of artificial sweeteners. 

Part 6: “The Solution,” provides guidelines for lasting treatment of obesity by addressing the hormonal imbalance of high blood insulin through proper nutrition, sleep, and stress management. 

 

The Rise of the Low Fat Era

Dr. Ancel Keys was a scientist interested in learning why Americans were suffering from higher rates of heart attacks and strokes than other nations. He hypothesized that high blood cholesterol levels cause heart disease and that eating less dietary fat was protective against high cholesterol and thus heart disease. 

In 1959 he published his recommendations to prevent cardiovascular disease, as Dr. Fung writes on page 202, prominent in these recommendations were:

  • Do not get fat; if you are fat, reduce. 
  • Restrict saturated fats; the fats in beef, pork, lamb, sausages, margarine and solid shortenings; and the fats in dairy products. 
  • Prefer vegetable oils to solid fats, but keep total fats under 30 percent of your calories. 

These recommendations became mainstream when they were incorporated into the 1977 Dietary Guidelines for Americans. According to this article, here is a summary of those first health goals: 

  • The first goal focused on energy balance and recommended that to avoid excess weight, Americans should consume only as much energy as they expended. Overweight Americans should consume less energy and expend more energy. This is one way to say “eat less, exercise more." This weight loss philosophy has been proven to fail for long term weight loss as it focuses solely on calories. Excess weight is not caused by calories alone, but by how food, along with other factors, influence hormones to control your body set weight. 
  • Increase consumption of complex carbohydrates and naturally occurring sugars.
  • Reduce consumption of refined and processed sugars, total fat, saturated fat, cholesterol, and sodium. 
  • Increase consumption of fruits, vegetables, and whole grains.
  • Choose low-fat and non-fat dairy products instead of high-fat dairy products (except for young children).
  • Decrease consumption of:
    • Refined and processed sugars and foods high in such sugars. 
    • Foods high in total fat and animal fat, and partially replace saturated fats with polyunsaturated fats (more on polyunsaturated fats later). 
    • Eggs, butterfat, and other high-cholesterol foods. 
    • Salt and foods high in salt.

 

The False Science Behind These Recommendations

It is crucial to understand the goals for these health recommendations: 

  1. Reduce excess weight. 
  2. Reduce heart disease. 

Unfortunately, the scientific evidence in 1977 was not what it is today. Most researchers back then agreed that excess weight is caused by too many calories in, and not enough calories out. 

Let me remind you again. Excess weight is not a caloric balance problem, it is a hormonal one. Every system in your body - your heart rate, breathing rate, hair growth, bone growth, etc - are ALL controlled by hormones, not volitional control. Your body set weight is no exception. You body set weight is largely controlled by two hormones, a careful balance between insulin and leptin. If you have excess weight, insulin has won the battle and your body is holding onto more fat than you would like. This was the first flaw in their reasoning. Part of the reasoning for eating low-fat was that a gram of fat has more calories than a gram of protein or carbohydrate, and if the aim is to reduce calories, one easy way to do that is to eat less fat. 

I was surprised Dr. Fung didn’t even mention in this chapter that dietary fat, of all three macronutrients, has the lowest insulin response. On page 212, Dr. Fung quotes Dr. Walter Willett of Harvard in his 2002 article entitled, “Dietary Fat Plays a Major Role in Obesity: No”, 

“Diets high in fat do not account for the high prevalence of excess body fat in Western countries; reductions in the percentage of energy from fat will have no important benefits and could further exacerbate this problem. The emphasis on total fat reduction has been a serious distraction in efforts to control obesity and improve health in general.”

The second error in reasoning came from the assumption that saturated fat intake causes heart disease. 

 

Saturated Fat Doesn’t Cause Heart Disease

One of Dr. Keys' hallmark research studies was the Seven Countries Study, a long-term observational study that compared rates of heart disease with various diet and lifestyle factors across seven countries. The takeaway from this study was that saturated fat is bad and “clogs” up your arteries, leading to heart attacks and strokes. But this study was a correlation, not a causation study, which can lead to misinterpretation and oversimplification of the data. 

Other main findings from the study included: 

  • Cholesterol levels predicted heart disease risk. Note, this study did identify that dietary cholesterol was NOT identified as a risk factor for heart disease. 
  • The amount of saturated fat in the diet predicted cholesterol levels. 
  • Monounsaturated fat and the mediterranean diet were protective against heart disease. 

Many researchers have poked holes through not only the results of this study, but the design. 

In his book, Good Calories, Bad Calories, Gary Taubes points out that Dr. Keys selected seven nations who he knew in advance would support his hypothesis that coronary heart disease is strongly influenced by fats in the diet. 

In decades of research since, many research studies have failed to find a causal link between dietary cholesterol, saturated fat, and heart disease. 

While your total cholesterol, low-density lipoproteins (LDL or “bad” cholesterol), and high-density lipoproteins (HDL or “good” cholesterol), are important to assess when looking at risk of cardiovascular disease, the flawed reasoning came when they assumed that high dietary cholesterol causes high blood cholesterol. 

Kris Gunners, a writer for Healthline Blog, summed it up nicely in his article: Saturated Fat: Good or Bad?

The predominant assumption was: 

“If saturated fat raises cholesterol (A causes B) and cholesterol causes heart disease (B causes C), then this must mean that saturated fat causes heart disease (A causes C).

However, at the time, this was not based on any experimental evidence in humans.

This hypothesis (called the "diet-heart hypothesis") was based on assumptions, observational data and animal studies (Weinberg).

The diet-heart hypothesis then turned into public policy in 1977 before it was ever proven to be true (Hite et al).

Even though we now have plenty of experimental data in humans showing these initial assumptions to be wrong, people are still being told to avoid saturated fat in order to reduce heart disease risk.”

He goes onto explain in detail the difference between HDL (good) and LDL (bad) cholesterol and concludes: 

“Saturated fats raise HDL (the “good”) cholesterol and change LDL from small, dense (bad) to Large LDL, which is mostly benign. Overall, saturated fats do not harm the blood lipid profile like previously believed.”

Several recent review studies that combined data from multiple other studies, found that there is no link between saturated fat consumption and heart disease.

One study published in 2010 reviewed 21 other studies with a total of 347,747 participants. The authors found no association between saturated fat and heart disease (Siri-Tarino et al).

Another review published in 2014 looked at data from 76 studies with a total of 643,226 participants and again found no link between saturated fat and heart disease (Chowdhury et al).

Kris Gunnars goes onto say: 

"What research has found is growing evidence of the protective benefits of certain fats, namely omega-3 fatty acids, a type of poly-unsaturated fat, and monounsaturated fats (omega-9 fatty acids). 

This does not imply that saturated fats are "bad," just that certain types of unsaturated fats are protective, while saturated fats are neutral.

So... the biggest and best studies on saturated fat and heart disease show that there is no direct link. It was a myth all along.

Unfortunately, the governments and "mainstream" health organizations seem reluctant to change their minds and continue to promote the old low-fat dogma.”

Dr. Fung states on page 204, “The seemingly strong link between heart disease and saturated fat consumption was forged with quotation and repetition, not with scientifically sound evidence.”

 

The Fall of the Low-Fat Era

The results of the low saturated-fat diet were an increase in omega-6 (polyunsaturated fats), namely from processed vegetable and seed oils, and an increase in carbohydrates. Omega-6 fatty acids are more pro-inflammatory than omega-3s and omega-9s (more on those later).

The resulting increase in carbohydrates, particularly from processed foods that were supposedly healthy and “low-fat” were often much higher in sugar to make up for the lost flavor of the fat. We thought we were being healthy, but ever since 1977 when those first recommendations were released, our nation has become sicker and heavier than ever. See this article for more information on that.

I think the proof is in the pudding. We’ve been given the recommendations, trying to follow them, and getting sicker. Clearly the recommendation to eat less saturated fat was just wrong and had consequences that were hard to foresee. 

More and more research is coming out disproving this whole low-fat era. Many whole foods that are very nutritious contain plenty of fat, take nuts, seeds, and avocados for example. We not only need to think of the macronutrient composition of food - carbohydrates, proteins, and fats - but also the nutrients in the foods we are eating. 100 calories of jelly beans and 100 calories of spinach are 100 calories of carbohydrates, but clearly there is a big difference in the nutritional value of these foods. Further, we need to move beyond thinking that 100 calories of jelly beans affects the body the same as 100 calories of spinach. It doesn’t. The macronutrient composition of food is so important for how that certain food affects your insulin levels and thus body set weight. The micronutrients (vitamins and minerals) in food can’t be ignored because this is what literally nourishes your cells. 

With the internet comes LOADS of information, it can be hard to sift through the mainstream advice to eat low-fat and trust what the research actually says. I want to remind you that the internet is full of information, much of which is old and outdated, you can’t always take what you read at face value. Further, if you don’t have a scientific background, it can be difficult to determine the quality of the study performed, and easy to draw conclusions from studies that don’t prove causation, that is largely how we got in this low-fat mess in the first place. 

The last part of this post is going to review the different types of fats, which one are best for you, which ones are neutral, and which ones to avoid. 

Good, Neutral, and Bad Fats

It is important to note that many fats have a combination of several types of fats, the foods in categories can overlap, but I put them in the category according the the majority of their fat content. 

Further, remember most of these foods also contain other macronutrients (proteins and carbohydrates). They are categorized as a "fat" because that is the majority of their composition. 

A high ratio of omega-6 to omega-3 fatty acids has been associated with cardiovascular disease, colorectal cancer, breast cancer, rheumatoid arthritis, and overall mortality (Simopoulos, 2002). Dr. Fung reports on page 206 that “it is estimated humans evolved eating a diet that is close to equal in omega-6 and omega-3 fatty acids. However, the current ratio in the Western diet is closer to a 15:1 to 30:1 ratio.”

When looking for the “optimal” ratio of omega-6 to omega-3 fatty acids in the diet, it appears that depends on your disease state and severity, but in general “a lower ratio of omega-6/omega-3 fatty acids is more desirable in reducing the risk of many of the chronic diseases of high prevalence in Western societies” (Simopoulos).

Good/Protective Against Heart Disease: 
  • Monounsaturated (AKA omega-9 fatty acids): avocado, avocado oil, olive oil, olives, cashews, walnuts, almonds
  • Omega-3 fatty acids (polyunsaturated): chia seeds, flax seeds, avocado, avocado oil, olive oil, olives, cashews, walnuts, almonds, herring, mackerel, lake trout, sardines, tuna, salmon, or halibut
  • Whole-food omega-6 fatty acids (polyunsaturated): cashews, almonds, walnuts, sunflower seeds
Neutral: 
  • Saturated fats: animal fat, eggs, butter, dairy products like cheese, milk and yogurt, coconut, coconut oil
Bad: 
  • Highly processed and refined omega-6 fat sources: Vegetable and seed oils and foods fried in them
  • Trans: margarine, shortening, processed foods 

 

Bottom Line

  1. Saturated fat in the diet has not been linked to heart disease or weight gain, in fact it may even be protective. 
  2. Consider the entire nutritional value of food, try not to ONLY think about foods in terms of “carbs, proteins, and fat.” Think about the other nutritional qualities of the foods like vitamins and minerals. Consider if it is mostly unprocessed. 
  3. The standard American diet has too high of a ratio of omega-6 to omega-3 fatty acids. The best way to lower this ratio is to eat less foods that contain processed and refined vegetable/seed oils or foods that are fried in them, and eat more of the whole food sources of omega-3s listed above. 
  4. You don’t have to be afraid of saturated fat anymore. Are there better options for fat? Yes. Are there worse options for fat? Yes. Consider it neutral. 

 

References

  1. Chapter 18. (2016). In J. Fung, The Obesity Code: Unlocking the Secrets of Weight Loss. Vancouver: Greystone Books. 
  2. Chowdhury, Rajiv, et al. "Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis." (2014).
  3. Hite, Adele H., et al. "In the face of contradictory evidence: report of the Dietary Guidelines for Americans Committee." Nutrition 26.10 (2010): 915-924.
  4. Simopoulos, Artemis P. "The importance of the ratio of omega-6/omega-3 essential fatty acids." Biomedicine & pharmacotherapy 56.8 (2002): 365-379.
  5. Saturated Fat: Good or Bad? Kris Gunnars. Healthline. https://www.healthline.com/nutrition/saturated-fat-good-or-bad#section1. Accessed October 20, 2019
  6. Siri-Tarino, Patty W., et al. "Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease." The American journal of clinical nutrition 91.3 (2010): 535-546.
  7. Weinberg, Sylvan Lee. "The diet–heart hypothesis: a critique." Journal of the American College of Cardiology 43.5 (2004): 731-733.

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