Anything to do with weight loss I avoid like the plague. So I was surprised to find myself reading a report on a six-year follow-up study that was done on contestants from the reality TV show “The Biggest Loser”. Frankly, how their metabolism changed with the rapid weight loss they achieved is nothing short of scary!
The study, Persistent metabolic adaptation 6 years after “The Biggest Loser” competition, found that six years after the dramatic weight loss on the TV show “The Biggest Loser,” most contestants regained the kilos. On top of that, their metabolism had slowed and they were burning fewer calories every day than they did before their stint on the show.
Researchers studied 14 contestants who participated in the 30-week competition, which involves intensive diet and exercise training. They started at an average weight of about 149 kg and ended at an average weight of about 91 kg. Six years later, when the six men and eight women went to the National Institutes of Health for follow-up measurements, their weight, on average, was back up to 132 kg. Only one participant hadn’t regained any weight. Similarly, percent body fat started at an average of 49 percent, dipped to 28 percent and returned to 45 percent over time.
However, their resting metabolic rate did not follow the same pattern.
The group as a whole, on average burned 2,607 calories per day at rest before the competition, which dropped to about 2,000 calories per day at the end of the competition.
Six years later, calorie burning had slowed further to 1,900 per day!
The slower the metabolism, the more a person has to cut back on calories in order to keep from gaining weight. There is a belief that if you just exercise enough you can keep your metabolism up, but that clearly is not the case. Their metabolisms didn’t speed up again when they regained the weight.
Your body is working to defend your energy stores (or fat mass). When fat mass is decreased (either by eating less or exercising more) most of us respond by changes in our brain circuitry that increase our tendency to eat. This produces changes in our neural, endocrine systems, and especially in muscle, that make us more metabolically efficient. In other words, it costs fewer calories to do the same amount of work.
As a positive, on average the group regained much of their weight but did maintain about 12 percent weight loss even after six years, had better cholesterol profiles, and none had developed diabetes during follow-up.
Something to ponder for those considering embarking on a crash weight loss program.