The neuroscience of why diets make you fatter

Many studies over many years show diets have steadily made Americans fatter. Why does dieting cause obesity? Blame the brain and its influence on emotional, hormonal, and neurochemical responses to dieting, deprivation, satiety, and shame.

Dieting is rarely effective, it doesn’t improve health, and it does more harm than good. Studies show regardless of the diet you follow, from vegan to paleo, you’re battling ancient neurological survival mechanisms that typically win out in the end. The brain is essentially wired to fight weight loss.

An obese man has a one in 1300 chance of reaching normal weight within a year and an obese woman has a one in 700 chance, and the majority of both these groups will gain back the weight in five years.

In fact, weight loss statistics show only about one percent of dieters keep the weight off permanently! What’s worse, almost half of dieters will gain back more weight than where they started.

Even just one diet can make you fatter: Research shows a single diet makes a man twice as likely and a woman three times as likely to become overweight.

And two or more diets? For women, that makes them five times more likely to become overweight.

Teenage girls who diet repeatedly are four times more likely to become overweight compared to their non-dieting peers, and 12 times more likely to binge.

Athleteswho compete in sports that require them to lose weight, such as boxing or wrestling, are three times more likely to be obese later in life.

Why the brain hates dieting

It’s important to understand the neurology behind deprivation, weight loss, and weight-related anxiety to appreciate why diets fail so many people.

In essence, the brain hates famines and is programmed to keep you at a steady weight based on your genetics and life experiences.

Dropping below the set point can cause a person to burn fewer calories, trigger the release of hunger hormones, and increase activity of brain chemicals such as dopamine that increase cravings for food.

Studies of both humans and rodents show binge eating is a normal mammalian response to food deprivation due to the effect of deprivation on brain chemicals that govern the response to rewards. They also show stress promotes cravings for sweeter, fattier foods.

Also, replacing the brain’s natural cues around hunger and satiety with the rules and regulations of dieting overrides its ability to regulate weight.

Just thinking you’re fat makes you fatter

Studies show just thinking you are fat will actually lead to increased weight gain, whereas teen girls who underwent a program to fight eating disorders stabilized their weight while the girls who didn’t do the program gained weight.

What to do when dieting has made you fatter?

The best choice to avoid weight gain is not to diet. However, most people — primarily women — have been on many diets by adulthood or midlife.

Research shows that as long as a heavier person exercises regularly, eats a healthy diet with lots of vegetables, and avoids risky behaviors such as smoking or isolation, their health outcomes are on par with a thin person’s who leads the same lifestyle.

Good brain health depends not on how fat or thin you are, but instead on healthy gut bacteria, positive stimulation, low exposure to sugars and processed starches (high blood sugar is very damaging to the brain), plenty of oxygen, reduced inflammation, and other basic healthy lifestyle factors. In fact, stressing about your weight and dieting is bad for the brain — stress is a notorious cause of accelerated brain aging.

Many people are pleasantly surprised to find that by letting go of weight loss and instead learning to love a healthy diet and lifestyle, the unwanted pounds melt away. But if they don’t, you can still be healthy and active. Ask my office for more advice on taking care of your brain health.