Obesity expert Dr. Louis Aronne says people who complain that they can't seem to lose weight no matter what they do aren't imagining things. They're merely the victims of their own longtime habit of eating a diet high in fat and simple carbohydrates.
Aronne says years of eating SAD (Standard American Diet) damages the hypothalamus, the part of the brain that regulates metabolism, and thereby disrupts the hormones that regulate appetite and satiety.
“The evidence is quite convincing: Eating fattening foods causes inflammatory cells to go into the hypothalamus,” he told Forbes Aug. 21. “This overloads the neurons and causes neurological damage.”
Aronne, director of the Comprehensive Weight-Control Program at New York-Presbyterian Hospital/Weill Cornell Medical Center, says years of consuming a diet high in simple carbohydrates and low-quality saturated fats impairs the appetite-regulating hormones leptin and ghrelin, causing people to overeat even when they're full.
Aronne cited a recent study published in the British Journal of Nutrition, where researchers at the University of Liverpool found that a high-fat, high-carb diet causes “metabolic dysfunction” and disrupts the brain pathways that regulate appetite. It is because of this neurological damage that some people complain about being hungry all the time despite consuming thousands of calories.
“It’s like your gas gauge points to empty all the time, whether or not the tank is full,” explained Aronne. “So you keep stopping for gas, and then eventually you start filling up gas cans and storing them in the back of your car because you’re so convinced you could run out of gas at any moment.”
Fortunately, the hypothalamic damage caused by years of poor eating can be reset by following a diet free of low-quality fats, processed foods and simple carbs. According to Aronne, it doesn't matter what type of diet a person follows as long as it's low in calories, fat and simple carbs. “If less fatty food comes in, it reduces the rate of damage,” he said.
While some experts may take issue with the indiscriminate reduction in dietary fat (since some saturated fats are healthy), almost all agree that reducing simple carbohydrates (such as rice, potatoes, pasta and junk foods) can dramatically improve one's overall health and body composition.
However, Aronne underscored that permanent weight loss takes time, as reversing the neurological and metabolic damage from years of overeating doesn't happen overnight. As an example, he pointed out that many of the contestants on the reality TV show "The Biggest Loser" who lose hundreds of pounds in a few months often regain the weight within a year or two.