Gina Kolata, a science writer for the New York Times, writes today about the results of research on the participants of the reality TV show “The Biggest Loser.”
Kevin Hall, a scientist at a federal research center who admits to a weakness for reality TV, had the idea to follow the “Biggest Loser” contestants for six years after that victorious night. The project was the first to measure what happened to people over as long as six years after they had lost large amounts of weight with intensive dieting and exercise.
The results, the researchers said, were stunning. They showed just how hard the body fights back against weight loss…
It has to do with resting metabolism, which determines how many calories a person burns when at rest. When the show began, the contestants, though hugely overweight, had normal metabolisms for their size, meaning they were burning a normal number of calories for people of their weight. When it ended, their metabolisms had slowed radically and their bodies were not burning enough calories to maintain their thinner sizes…
What shocked the researchers was what happened next: As the years went by and the numbers on the scale climbed, the contestants’ metabolisms did not recover. They became even slower, and the pounds kept piling on. It was as if their bodies were intensifying their effort to pull the contestants back to their original weight.
But the human body doesn’t simply slow down metabolism in response to weight loss.
Dr. Proietto and his colleagues looked at leptin and four other hormones that satiate people. Levels of most of them fell in their study subjects. They also looked at a hormone that makes people want to eat. Its level rose.
“What was surprising was what a coordinated effect it is,” Dr. Proietto said. “The body puts multiple mechanisms in place to get you back to your weight. The only way to maintain weight loss is to be hungry all the time.”
Kolata is right to point out that the significance of the research conducted by Dr. Hall is that he followed the participants from “The Biggest Loser” for six years. But this is information that has been identified previously in shorter-term studies. Kolata herself chronicled much of this in her book Rethinking Thin: The New Science of Weight Loss – And the Myths and Realities of Dieting, which was published back in 2008. You can read an excerpt here. The truth is, much of what we think we know about obesity and weight loss is regularly challenged by science. For example, here are the conclusions of research by Dr. Albert Stunkard of the University of Pennsylvania back in 1986:
The scientists summarized it in their paper: “The two major findings of this study were that there was a clear relation between the body-mass index of biologic parents and the weight class of adoptees, suggesting that genetic influences are important determinants of body fatness; and that there was no relation between the body-mass index of adoptive parents and the weight class of adoptees, suggesting that childhood family environment alone has little or no effect.”
In other words, being fat was an inherited condition.
Having studied this one for years now I can tell you that almost everything we think we know about obesity and weight loss is a myth. For example, we all assume that people who are obese eat too much because they lack will power. But imagine the kind of will power it takes to accomplish what one contestant on “The Biggest Loser” described as his daily routine.
Wake up at 5 a.m. and run on a treadmill for 45 minutes. Have breakfast — typically one egg and two egg whites, half a grapefruit and a piece of sprouted grain toast. Run on the treadmill for another 45 minutes. Rest for 40 minutes; bike ride nine miles to a gym. Work out for two and a half hours. Shower, ride home, eat lunch — typically a grilled skinless chicken breast, a cup of broccoli and 10 spears of asparagus. Rest for an hour. Drive to the gym for another round of exercise.
If he had not burned enough calories to hit his goal, he went back to the gym after dinner to work out some more. At times, he found himself running around his neighborhood in the dark until his calorie-burn indicator reset to zero at midnight.
In other words, other than sleeping, his entire day was devoted to losing weight. This is one of the people who recently learned that the result of these efforts is that his body is now producing hormones that make him feel hungry all the time and his metabolism has slowed to the point that he needs to consume 800 fewer calories per day than normal-weight people in order to avoid putting on pounds.
Why do the myths continue when the science is saying otherwise? Much of it is because they have become culturally embedded. But the $60 billion-a-year weight loss industry also has a lot a stake in maintaining them. Until we reject these myths and start following what science is telling us, we will continue to see the obesity problem grow.
