It’s a common refrain among people trying to get healthy: They lose the weight, mock their ex or celebrate, and then, by dribs and drabs, they regain the weight until they’re right back where they started. But this isn’t something doctors had the ability to study, because it’s difficult and expensive to find a bunch of people and make them all lose a dramatic amount of weight. Fortunately, TV stepped in to give them an opportunity to learn how we lose, and regain, weight.
After the end of season eight of The Biggest Loser, a research team began working with Danny Cahill, the winner, and the rest of the show’s cast to see how they maintained weight. Cahill, who ended the series at 191 pounds, has seen 100 pounds return over the last six years, for example. But why?
The answer was their resting metabolisms, or what you burn when you’re not doing anything. It’s well known that weight loss slows your metabolism, and the more dramatic the loss, the slower your metabolism gets. But what surprised the researchers was, over the next six years, the entire cast saw their resting metabolisms continue to drop. In other words, their bodies were actively fighting to put the pounds they’d lost back on. Cahill, for example, has to eat less than 2,360 calories a day to maintain his weight of 295. On a person who just weighed that to begin with, that would be what they need to eat to lose weight.
In fact, it’s so difficult, that some of the season eight cast are heavier now than they were when the show started. Only one contestant, Erinn Egbert, has managed to keep the weight off and even lose more, and even she’s fighting a resting metabolism. Interestingly, contestant Rudy Pauls had bariatric surgery, and that staved off weight gain. But this process has been ongoing for six years, and it’s not clear that it will ever stop.
One of the culprits appears to be leptin, a hormone generated by fat cells that inhibits hunger. The more weight you lose, the more leptin is taken out of your system, making you hungry all the time and making it easier for the body to indulge; Cahill reports “blacking out” and then eating an entire bag of potato chips. Research is increasingly finding that as you lose weight, leptin and other hormones that regulate hunger drop, while hormones like ghrelin, secreted by the stomach, stay the same or rise. This may be why bariatric surgery is an effective weight-loss tool; there are fewer cells churning out ghrelin.
The good news is that if you just want to get five pounds off, or turn into someone else completely just temporarily, this is unlikely to affect you. Your body has a weight range, not a specific weight, and you can probably fit into it. For the obese who struggle to keep off the weight, though, it’s a good reminder that it’s not a matter of “will power.” They’re literally fighting their own bodies.
(Via the New York Times)