Weight regain after ‘The Biggest Loser’ television show is common.  The reality television show takes contestants away from their homes and places them in a controlled environment for weeks where they are fed a very low calorie diet and an exercise plan.

The contestants lose weight, feel better and go home. But what happens later? Most know they regain their weight, but the question is why? In a study in the journal Obesity (found here) they measured the metabolism of those patients.  Technically they measured the resting metabolic rate (RMR), which is means how many calories does their body burn when they are at rest. It turned out that all of the contestants studied not only had a lower resting rate after the competition, but that this rate persisted for years later.

That means, not only did their metabolism slow down, but it remained slow and slower than would be expected for their height and weight and age.

In following up with other laboratory levels this was not explained by thyroid hormone (the favorite hormone that family doctors try to add to obese patients), or other levels. In contrast, weight loss surgery patients have a decrease in resting metabolic rate, but this stabilizes after six months.

Think of it this way: your body has an appetite thermostat where what you eat maintains your current weight. If you go on a diet you lose weight, and it is like opening the window on a cold day – the thermostat kicks in and the heater warms the room. When you go on a diet your appetite thermostat kicks on and you eat more and regain the weight.  Weight loss surgery permanently changes that thermostat to a lower level and maintains that level.

The body’s appetite thermostat permanently changes after weight loss surgery, but not after low calorie diet and exercise programs.

The body has a metabolic thermostat that resets lower after diets

While most of the contestants did not regain all of their weight, many were working harder than expected to maintain the weight loss. Every single contestant, at the end of competition vowed “I’m never regaining that again.” Several of the contestants have had weight loss surgery.

Lessons Learned from This Study

The body adapts quickly to a diet and exercise program and vigilance is required.

Insulin levels were up mildly, but did not explain either the body’s adaption to lower metabolism or weight regain.

Thyroid hormone levels do not explain weight regain.

Weight Loss Surgery provides long-term and sustained weight loss – a new metabolic set-point.