Diet usually matters more for weight loss than exercise, but it turns out that Biggest Loser contestants who managed to keep the weight off have to exercise a lot. But if you and I aren't Biggest Loser contestants, does that mean anything for us?
Photo via Visualhunt
Probably not, says Yoni Freedhoff, an obesity specialist not involved in the study. Most people who have lost weight didn't do it with an extreme short-term regimen on national TV. And many former contestants now have gigs as motivational speakers or personal trainers, he says, so they have to exercise like crazy to keep their source of income. Most of us have the opposite pressure. We have to find time in the day to exercise, after making sure we get in our work hours.
In the study, researchers - including one obesity specialist who had been a Biggest Loser contestant herself - divided 14 contestants into two groups. Half had mostly gained the weight back over six years, while the others had kept off a lot of it. On average, people in this group were 37kg lighter than when they started. (The average weight loss, initially, was 54kg.)
Then the researchers used a few techniques including urinalysis to test (not just ask) how many calories people were eating and burning in real time. Sure enough, the people who kept the weight off were exercising a lot more than those who didn't. We already know that people - even specifically Biggest Loser contestants - end up with a slower metabolism after they lose a lot of weight. It may take dietary changes to lose weight in the first place, but maintaining seems to depend more on exercise.
The successful contestants' calorie burn was equivalent to 80 minutes of moderate activity, such as walking, or 35 minutes of vigorous activity. Every day. "Just because we all have the same number of minutes in a day, doesn't mean we're all going to prioritise those minutes in the same way," Freedhoff says. "Prioritising 35 to 80 minutes a day of exercise is beyond the realistic reach of most of the population."
But that doesn't mean exercise is hopeless. Freedhoff emphasises that any amount of exercise you can manage is still good for your health, whether or not it helps you lose weight or keep it off. The same is true for healthy eating and other behaviour changes like getting sleep or moderating your drinking. So, do exercise - but do it for yourself, not because a TV show says you should.