Contestants on the TV show “The Biggest Loser” may not be “losers” after all. A recent study of Season Six contestants has revealed that six years after the show ended, most of the participants regained a substantial amount of weight.
For those unfamiliar with the show, overweight and obese contestants compete for a cash prize by demonstrating the greatest weight loss by percentage. Along the way, contestants receive coaching from trainers and nutritionists.
So, after achieving their weight loss goals and learning the keys to weight loss, why do they gain the weight back?
The secret lies with resting metabolic rate (RMR). RMR is a measure of the energy (calories) required to keep you alive while your body is at rest. After thirty weeks of a hard-core weight loss regimen, the RMR of most of the contestants went down. This means that fewer calories were required to keep them alive, and to continue losing weight they had to reduce the calories they ate even further.
Our bodies reduce the number of calories we need because they are really great at adapting to change. For example, when our bodies are cold, they shiver to warm us up. The same principle holds true for body weight. In the past, humans did not have food readily available to us, and during times of scarcity, our bodies would reduce their RMR to maintain the same weight. Now, when we try to lose weight, we reduce the calories we consume. Our bodies basically say, “Whoa, we aren’t getting our normal amount of calories here. Food must not be available, so we have to make every calorie count!”
Six years after the end of the show, contestants on “The Biggest Loser” still had a lower RMR than what they started with, which suggests two things. One, it seems like when we become overweight, our body “resets” what it thinks our normal weight is. Two, when we lose weight, it takes a really long time for our bodies to recognize that our lower weight doesn’t mean we are starving. Our bodies will continue to fight the lost weight, and try to gain it back years after weight loss. Other studies suggest that this change in RMR occurs after a diet change but that weight loss generated by proper exercise does not change RMR.
Ultimately, contestants on “The Biggest Loser” tend to keep the pounds off better than the average overweight or obese person after a weight loss regimen. However, even with the help of trainers and nutritionists, losing weight (and keeping it off) is a big challenge.
Edited by Wilfred Wong