Why are so many people overweight in developed countries? What is the main cause of weight gain?
There are many factors that cause weight gain: genetics, disease, overeating, and a sedentary lifestyle. However, the main cause of weight gain in modern times is the habit of constant eating. Most people eat three meals a day with several snacks in between. Constant feeding causes constantly elevated insulin levels, and insulin is a fat-storage hormone.
Here’s how modern eating habits contribute to weight gain.
Modern Eating Habits Cause Weight Problems
What is the main cause of weight gain? According to Gin Stephens, the author of Fast. Feast. Repeat., the modern habit of eating continually causes high blood glucose levels—that is, the body never gets a break from converting food into glucose. This leads to chronically high insulin levels, since insulin releases to store all that glucose. Since we’re never out of glucose or glycogen, the body can’t access its fat stores, burn them, and lose weight.
(Shortform note: In The Obesity Code, Jason Fung argues along these lines in more detail. Continuing the “wallet and bank” metaphor, he argues that, as with money, we prefer to use our wallets (glycogen)—and when we deplete them, we’d rather fill them back up than get money from the bank (fat stores). By eating without long breaks, you prevent your body from accessing fat stores, and at the same time you keep your insulin levels high, which promotes increased storage of glucose as fat. In Fung’s view, this leads to obesity.)
“Nutritionism” and Diet Confusion
In In Defense of Food, Michael Pollan argues that when Americans began looking to medical experts to guide how we eat, we lost touch with tradition that once guided us to eat well. Pollan explains that the doctrine of “nutritionism,” or looking for the magic nutrient-based solution to health problems, produced conflicting views about what is healthy.
This is because such research focuses on nutrients rather than the whole-food contexts in which they exist. Because studies have concluded that certain nutrients are problematic instead of certain foods, we’ve had trends such as the low-fat era, the anti-cholesterol era, the anti-carb era, and so on—and oddities like low-fat ice cream.
Pollan stresses that so long as we remain confused about diets and nutrition, we’ll struggle to reclaim our health and to change our lifestyles for the better. To change this, his rule of thumb is to eat real, mostly plant-based food in moderation and to listen to your body to know when you’re full.