The Myth of Metabolism

Evolutionary anthropologist Herman Pontzer explains why you can’t run away from your fat.

While Pontzer was in Tanzania, he studied the Hadza tribe who hunt their food with simple tools and build their own houses from mud. You’d think they burned calories, right? Quite the contrary. What he discovered was they burn the same amount of calories as does a couch potatoe. It doesn’t stop there with the one tribe. Pontzer traveled the world studying metabolism and his results will surprise you.

For personal trainers and weight management specialists like myself, I found it quite interesting. Before sharing his results, let me define metabolism and it’s purpose. Metabolism is a chemical process that occurs within a living organism converting food and drink into energy. During this biochemical process, calories in food and beverages are combined with oxygen to release the energy your body needs to function. According to the Mayo Clinic, metabolism is linked to weight, but slow metabolism is rarely the cause of excess weight gain. Although it influences your energy level, how much you eat and drink along with how much physical activity you get are the things that ultimately determine your weight. In addition, your body needs energy for all the hidden functions such as breathing, sleeping, blood circulation, hormone activity, and cell growth and repair, and the calories your body uses to carry out these functions is called the metabolic rate-metabolism.

Now that you have a basic understanding of metabolism, Pontzer explains why exercise is so hard to burn calories and dieting is dangerous to metabolism.

His first claim is that exercising more won’t increase calories burned. The number of calories burned a day stays consistent regardless of activity level; the average adult over age 50 burns 2500 calories a day, which is close to the daily caloric budget, although it does depend on body size. When you exercise more, the body simply lowers the number of calories burned through other bodily functions. Therefore, metabolism remains constant.

Exercise is supposedly linked to weight loss, so the claim is if I’m not burning calories, how much weight can one lose? The fact is when people exercise, inflammation levels go down because your body is spending your energy budget on exercise not on the inflammation. Inflammation is what your body does with the extra calories when it doesn’t exercise, so exercising reduces the risk of most diseases caused by aging and obesity.

In regards to extreme diets, it can lower metabolism, but the claim is increasing it will help with burning calories. Pontzer’s findings shows quite the contrary. It makes sense to turn our metabolism down because it preserves our life time of famine. On the other hand, increasing the metabolism makes you more hungry, increasing your risk of starvation.

It is true that athletes who train on a consistent basis (especially the professional ones) tend to eat and burn more calories than the average person. That doesn’t mean you increase your metabolism. More training just ramps up your energy level according to Pontzer. Eventually, elite athletes settle back into their constant range.

Stephen Petrine who authored this article found information that states that certain diets and workouts promise to supercharge the metabolism. Pontzer’s research shows otherwise. There is no such thing as a diet that can speed up your metabolism. The most effective diet is one that provides all the healthy nutrients your body needs while reducing your calorie intake to below calorie budget. That’s the tool for weight loss not so much exercise. Benefits of exercise are preserving physical fitness, assisting with preventing metabolic diseases, and heart health.