If I told you that fat doesn’t actually make you fat, would you believe me? Based on everything we have been taught since the release of the original U.S. Dietary Guidelines in the 1970s, I would not be surprised if you called me crazy. After all, fats are much more nutrient- and caloric-dense than the other two macronutrients – carbohydrates and proteins. Fat has around nine calories per gram, whereas protein and carbs have around four calories per gram. But, if we are going to understand accept the Ketogenic way of eating, we have to start by debunking this myth.
When they hear about Keto, most people joke that it “can’t be healthy because all of that fat would clog your arteries.” It makes sense that we assume dietary fat would cause actual fat in the body, well, because they are the same word. But, unfortunately, there is no science to prove what we call the “Diet Heart Hypothesis” (the belief that fat causes plaque to clog the arteries of the heart).
And, while Nina Teicholz has written a 340-page book that is a consolidation of nearly 100 years of research on this topic, Jimmy Moore published a wonderful book explaining the ins and out of this myth, and Dr. Zoe Harcombe details this fallacy here, I will do my best to explain this myth in layman’s terms given that this tends to be the greatest barrier for people embarking on a Ketogenic/low-carb lifestyle.
The belief that fat is bad and causes heart disease is based on a study by Ancel Keys done in the 1950s in response to the rising rates of heart disease and the heart attack of then-President Eisenhower. The challenge is that, while Keys did identify an increase in heart disease related to fat consumption for the seven countries he reported – Japan, Italy, England, Wales, Australia, Canada, and the United States – there are three major problems. First, he didn’t report the data from the additional 15 countries he studied that disproved his hypothesis (e.g. Ireland, France). Second, he didn’t consider other nutritional variables outside of saturated fat, like the consumption of sugar or highly-processed polyunsaturated vegetable oils (e.g. margarine), both of which happen to correlate to cardiovascular disease. Third, he didn’t factor in variables outside of nutrition, such as lifestyle differences related to things like exercise or the rapidly-rising rates of smoking at that time in history.
Another fascinating consideration about the relationship between fats and heart disease is that updated research is showing three important things about heart health:
- Plaque buildup on the walls of arteries is actually correlated to inflammation, which is often triggered by what we are eat. The way this works is that damage done to arteries via inflammation causes the body to protect itself by patching the “holes” created by inflammation with plaque. This leads to plaque buildup and decreased function.
- The LDL (Low-Density Lipoprotein) cholesterol levels previously thought to be “bad” cholesterol are not necessarily understood to be “bad” anymore (although even simplifying that there is either “good” or “bad” cholesterol is not exactly accurate, anyway.) Instead, the key factor with heart health and cholesterol is starting to be understood as the size and density of cholesterol particles. Some forms of cholesterol are light and fluffy (the kind that doesn’t tend to be viewed as harmful to heart health) and some are dense and hard (the kind not thought to help heart health).
- The consumption of healthy fats (e.g. monounsaturated fatty acids like olive oil, animal proteins, macadamia nuts) actually tends to improve heart health, as is measured by various factors, including triglycerides, HDL (High-Density Lipoprotein, and body mass). A wonderful summary of this affect can be found on Dr. Bret Sher’s website, who had deemed himself the “Low-Carb Cardiologist.”
If nothing more, when I think of the belief that fat makes someone fat, I think of the French. The French enjoy a dish called foie gras, which is the fatty liver of a goose. And, how do they make this liver fatty? By literally stuffing (inhumanely, I would argue!) the bird with grains. Now, if fat (and not carbohydrates) made us fat and created issues with our internal organs (e.g. fatty livers), why wouldn’t the goose be stuffed with fat?
I also think about my own story related to a low-carbohydrate/Ketogenic way of eating. Neither I nor anyone I know who has embarked on their high-fat journey has had any heart issues or has gained weight. In fact, I repeatedly see and hear about the opposite. So, if there were a concern about the connection between eating a high-fat diet and getting fat or developing heart disease, the leading international research organization on a low-carb/high-fat way of eating through which I am a Nutrition Network Practitioner, The Noakes Foundation, would not exist. And, I would be the first in line to warn about the dangers of such a nutritional profile! However, I have yet to find or hear any leading researcher on the topic argue that fat does, indeed make us fat and clog our arteries. So, the choice is up to you: stay stuck in outdated dogma based on flawed science or open your mind to an approach that may just change your quality of life.
