Obesity continues to be an increasing problem in the United States. In 2013, only 38 percent of the U.S. population had a healthy weight. As a result, new diets are growing like apples on a tree, but the risk of obesity may be increased by dieting.
Neuroscientist and science writer Sandra Aamodt recently did a talk for TEDGlobal, in which she explains how she came to the conclusion that diets can actually make people gain weight and increase the risk of obesity. “Hunger and energy use are regulated by the brain. The brain cannot tell you whether you have to lose weight or not, but the brain does have a sense of what you should weigh within a range of 10 to 15 pounds,” Aamodt says. According to her, it is difficult and likely impossible to fool the brain when it comes to dieting and losing weight. She explains, “With a dozen of signals in the brain telling the body to gain weight and another dozen to lose weight, the brain works like a thermostat. It keeps the body weight stable as it loses some or gains some, like a thermostat regulates the temperature in a room, even when a window is open in winter.”
Recent studies have also shown that the brain has a set point. This set point can go up if the body gained weight for a longer period, but it rarely goes down, even when weight has been lost for a period of seven years. Dr. Rudolph Leibel from Columbia University explains that a body on a diet burns less energy. In fact, according to Leibel, a loss of 10 percent in body weight can result in burning 250 fewer calories per day. This means people are required to eat significantly less for the rest of their lives in order to keep that weight off, while in the meantime, the set point of the brain will never go down and will always tell the body it is hungry. If people continue to eat normally, the body still burns 250 fewer calories than it did before, resulting in an increased risk of obesity that may be caused by dieting.
Psychologists divide people into two groups: people who eat when they feel hunger are intuitive eaters and people who are frequently dieting are controlled eaters. Aamodt says there have been studies showing that intuitive eaters are less likely to become overweight. In addition, they think less about food. Aamodt also speaks from her own experience, saying, “I was 13 years old when I was on my first diet. Now that I do not diet any longer, I am an intuitive eater and I never think about food anymore. I even forget there is chocolate in the house.” Controlled eaters, however, are more vulnerable to overeating, food advertising and the all-you-can-eat buffet. Aamodt says, “A small indulgence like a scoop of ice cream is more likely to lead to a food binge.”
In the past, an increasing number of scientists have been working on studies, proving that dieting may increase the risk of obesity. One of the studies showed that females who went on their first diet in their early teens are three times more likely to become obese five years later, even when they started at a healthy weight.
By Diana Herst