People who watch The Biggest Loser either love it or hate it. Some find it inspiring. Others see it as body-shaming on steroids. However you feel about it, you can’t deny the results are impressive. Contestants lose 30 to 50 percent of their body weight after only 7 months. For individuals who have struggled with obesity their entire lives, it must literally seem like a lifesaver. It flies in the face of the traditional recommendation to lose no more than one to two pounds per week.

These oversized results are the product of intense exercise for seven or eight hours a day and tightly controlled calorie intake. Sadly, contestants who follow this grueling regimen lose more than weight. They lose metabolism.

Research published in the journal Obesity gathered data from 14 of the 16 contestants from Season 8 of The Biggest Loser. They took measurements before the show began, at the end of the show, and six years after the show was over.

These fourteen contestants lost an average of 39 percent of their body weight during their seven months on the show. But at the six-year follow up, they had regained most of that weight. They were down only 11 percent from their original weight.

The rest of the data tells us why this was the case. The metabolic rate of contestants fell during their drastic weight loss. And it never recovered. At the start, contestants burned about the amount of calories predicted by their size and age. But at the end of six years, contests were burning 500 calories per day fewer than predicted.

And if that wasn’t enough of an insult, it turns out that leptin, a hormone that signals when we’ve eaten enough, fell during weight loss. Afterward, it recovered to only 65 percent of its original level. So while metabolism shrunk, hunger grew. It’s a perfect recipe for regaining weight.

This is why a simple calories-in/calories-out approach doesn’t always work so well. Our bodies adjust over time so it gets harder to resist eating more calories. And the calories-out side of the equation is a moving target. This was the point of research by Dr. Kevin Hall and colleagues. They evaluated the physiological changes that happen during weight loss to create a model for weight loss planning.

The resulting tracker allows you to plan a realistic weight loss goal. For example, if you just assumed a steady metabolic rate, a daily deficit of 610 calories would get you to a weight loss of 50 pounds in 286 days. But the tracker puts it at a year because of the shifts in metabolic rate.

But rather than accounting for a decrease in metabolic rate, why not prevent it.? Remember a few key facts when you try to lose weight.

Quality of calories counts as much as quantity. If you consume mainly empty calories (hello, sweets and processed grains) your body is starved of nutrients. Vitamins, minerals and other components of whole foods are vital to the biochemical activities that keep you running. Choose healthy proteins and fats as well as a variety of colorful fruits and vegetables to meet your caloric needs.

Get plenty of sleep. It seems like every month we learn something new about the damage caused by poor sleep. We know it contributes to weight gain. Investing in sleep is an investment in your health.

Exercise to prevent weight gain. You aren’t going to burn enough calories in a normal workout to offset a bad diet. But it is a vital tool for preventing weight gain and protecting your health in general.

Get a clean bill of health. If you struggle with weight in spite of good habits, speak to your doctor. Be sure a health problem or medication isn’t sabotaging your weight.

Weight loss is far more complicated than we want to believe. And our desire for big results fast - like those we see on The Biggest Loser - is not helping the problem. To get results that last, play the long game: develop habits that build health instead. Just as there truly is no free lunch, there really is no quick fix.

Amy Rogers MD is not a practicing physician and nothing written here should be taken as medical advice from either Amy or AssetBuilder. Medical decisions should be made with care in consultation with your health care provider.