1958: A handsome fit man stands before a chalkboard on a CBS documentary. He has a row of 10 little wooden men standing in front of him. He flicks five of them and claims that heart disease will kill 5 out of 10 Americans. The culprit according to our handsome man, Dr Ancel Keys, is dietary saturated fat. A combination of charisma, bad science and lobbying from the margarine industry sold the whole of America, and then the world, a lie. This lie would falsify tradition, sell margarine and destroy the health of millions over the next decades.
The Minnesota Coronary Experiment was a massive study involving thousands of adult residents from six state mental hospitals and one nursing home. The study subjects were divided into two groups and were fed two different diets for around 3 1/2 to 4 1/2 years. One experimental diet was high in saturated fat, the other high in polyunsaturated fat. Upon closer investigation, it was found that the high saturated-fat group’s diet contained lots of margarine and shortening (both loaded with trans fat, and not much if any butter or natural animal fats), lean meats, skim milk and cheeses to which corn or other vegetable oils were added, along with some margarine, and no butter or natural animal fats. The study concluded that high polyunsaturated fats group showed lower levels of cholesterol, lower risk of heart disease and stroke compared to the high saturated fat group. But in fact, the high saturated fat group was actually high in trans fats. Keys simply blamed saturated fats, ignoring the whole story. This started one of the biggest myths in nutrition, “All saturated fats are bad”
Myth 1: All saturated fats are bad
Technically speaking no fats present in nature in its natural form are unhealthy. The problem occurs when heat is applied to certain kinds of fats. Vegetable oils (canola, sunflower etc.) contain polyunsaturated fatty acids which are prone to oxidative damage. When they are heated they get oxidized and turn into trans fats which put the human cells under oxidative stress when consumed by giving rise to free radicals. These free radicles are a cause of a whole host of diseases including cancer. Unfortunately, extraction of such vegetable oils from their parent seeds involves high temperatures, which means by the time they are in your house they have already undergone oxidation thus rendered unfit for consumption. On the other hand, monounsaturated fats (coconut oil, olive oil, butter) can endure heat and cause very little to no oxidative stress on the body when consumed. Of course, this is simplified for better understanding and if you are interested in the nitty-gritty details please look at part 2 of the book “Deep Nutrition” by Dr Cate Shanahan and at the work of Dr Gerhard Spiteller.
So what fats are healthy and ok to h(eat)? I will include a list of fats as described by Dr Shanahan. The following is a list of good and bad fats and the effect of heating them.
|Fat||Good or bad||When exposed to heat|
|Olive oil||Good||Better raw but safe|
|Peanut oil||Good||Better raw but safe|
|Butter||Good||Better raw but safe|
|Ghee||Good||Better raw but safe|
|Animal fat (lard, fish oil)||Good||Better raw but safe|
As a rule of thumb fats close to nature and in their pure unrefined form seem to be the best option. They are mostly saturated and monounsaturated fats. When consuming them refined, it is beneficial to look for a fermentation process before heating (e.g. cheese, ghee). Natural fermentation is a process which has withstood the test of time and is present across cultures. These traditional products contain monounsaturated fats and a load of micronutrients. The fermentation process they are put through uses up the lactose in them which helps humans to digest these products better (More than 60% of the adult population is lactose-sensitive). Furthermore, certain types of yoghurts and cheeses contain probiotics which help improve digestive health.
Myth 2: Fat loss = Calories in < Calories out
The fitness community has made it fashionable to count calories and to an extent, it works but so does not counting calories. In fact, fasting (time restricted eating) works as good as, if not better, than counting calories (Alhamdan et al. 2016). There is a misconception that if calories consumed are less than calories burned then you lose weight a.k.a. being in caloric deficit. Looking at the physics it is true but the way nutritionists define calories and the way physicists do is very different.
Traditional nutrition assumes all nutritional calories you put inside your body in form of foods are converted into energy output. This energy either contributes towards BMR (Basal metabolic rate) or towards the energy expended during exercise. One of the things ignored by nutritionists is the body’s ability to thermoregulate. For example, if you ingest cold water in your body the body must warm it up to 37 degrees which require the body to burn calories so cold water has negative nutritional calories. Similarly, when you ingest warm water the body must cool it down, which again burns calories (Just like a refrigerator requires electricity to cool), so warm water also has negative nutritional calories. Nutritionists consider water to have no calories. They classify calories invested in the process of thermoregulation under BMR. BMR is NOT a constant value. BMR is a multivariable equation and some of the variables involved are exercise, body composition, calorie intake and calorie output. The assumption of traditional nutrition is that all the calories you ingest are absorbed, which is ridiculous. Digestion and absorption are nowhere in the picture and if talked about are done so in a very reductionist fashion. Reducing the whole science of nutrition to calories in and calories out is not even scratching the surface of an optimum human diet.
The point I am trying to make is that although modern-day science is well equipped to look at specific things in great depth, it is nowhere close to being perfect. We are always finding new insights and falsifying previous ones, that is the nature of research. Unfortunately, a person requires expertise in biochemistry, physics, biology and understanding of statistics (which can be easily manipulated) to understand good science from crapy research. There are thousands of papers published on various topics every day and anyone who claims to be on top of ALL the modern day science is lying. Nowhere is this truer than in the field of Nutrition. Just look at the different fad diets present today.
So what can we do about it? I propose to disregard such crude methods of measuring what you are eating. Instead, look at it from a performance, longevity and wellness angle. A few good questions to ask are: What do the healthiest and fittest people I know eat? Does the food I eat make me feel good subjectively? Is that true before, during and after eating and also in the long run? By looking at food differently and getting connected with our instincts I believe we can achieve better health using simpler yet more effective indicators for understanding the nutrition we need.
Alhamdan, B. A., A. Garcia-Alvarez, A. H. Alzahrnai, J. Karanxha, D. R. Stretchberry, K. J. Contrera, A. F. Utria, and L. J. Cheskin. 2016. “Alternate-Day versus Daily Energy Restriction Diets: Which Is More Effective for Weight Loss? A Systematic Review and Meta-Analysis.” Obesity Science & Practice 2 (3): 293–302.
Deep Nutrition — by Dr Catherine Shanahan