Study of ‘Biggest Loser’ Contestants Confirms Just How Dramatically the Body Resists Weight Loss

Danny Cahill went from 430 pounds at the start of the show to 191 at the end; he has since gained back 100. (Photos: Before: Chris Haston/NBC Universal via Getty; After: Trae Patton/NBC Universal via Getty)

It is a truth universally acknowledged that diets rarely work and that those who lose significant weight tend to gain it back over time. Now a new study of contestants from the reality show The Biggest Loser (Season 8) sheds new light on why maintaining weight loss is so hard.

The findings, published in the journal Obesity, tracked 14 of the show’s contestants for six years after the conclusion of the eighth season. The New York Times highlighted some of the dramatic and disheartening numbers. 

Winner Danny Cahill dropped from 430 pounds to 191; he has since gained back 100. Dina Mercado went from a preshow weight of 248 pounds all the way down to 173.5 pounds when the show ended; she’s now 205.9 pounds. Sean Algaier slimmed down from 444 pounds to 289 at the finale; he now weighs 450.

As part of the research, the scientists checked the subjects’ resting metabolism, or basal metabolic rate (BMR) — the number of calories your body burns each day while completely sedentary, with no physical activity whatsoever. At the beginning of the show, although all the contestants were overweight, they had average resting heart rates for their sizes. At the end of the show, after their extreme diets, their metabolisms had slowed to a crawl.

It is not uncommon to have a slow metabolism just after significant weight loss, so researchers weren’t alarmed to see incredibly low BMRs just after the show. They were, however, shocked when the contestants’ metabolisms failed to adjust to their new, lower weights. The BMRs actually just kept getting worse, and the weight came flooding back.

Dina Mercado went from 248 pounds to 173.5; she has since gone back up to a weight of 205.9. (Photos: Before: Chris Haston/NBC Universal via Getty; After: Trae Patton/NBC Universal via Getty)

Cahill burns 800 fewer calories than average for a man his size, while Algaier’s BMR is 458 calories less than expected for his weight. Mercado now burns 437.9 fewer calories than a woman her size. “It is frightening and amazing,” Kevin Hall, the study’s lead author and a metabolic expert at the National Institute of Diabetes and Digestive and Kidney Diseases, told the New York Times of such dramatic results. “I am just blown away.”

It’s hard to compare other weight-loss programs with the extremes of The Biggest Loser, says Reshmi Srinath, MD, an assistant professor of endocrinology, diabetes, and metabolism at the Icahn School of Medicine at Mount Sinai. However, these results do confirm that universal truth about weight loss — in a big way.

When we shed pounds, our bodies fight hard to reapply them. “Multiple mediators act at the level of the hypothalamus to suppress our metabolic rate and promote weight regain,” Srinath tells Yahoo Beauty. “This study emphasizes just how challenging it is to lose weight and maintain the weight loss.”

Not only are we fighting our lower metabolisms with weight loss, but we’re fighting hormone fluctuations that would generally help bodies remain at a set weight, says Holly Lofton, MD, an assistant professor of medicine and the director of medical weight management program at NYU Langone Medical Center.

Spikes and drops in hormone levels cause massive cravings, Lofton tells Yahoo Beauty. “The levels of appetite-reducing hormones like leptin, which researchers measured in the study, along with amylin, insulin, and glucagon like peptide 1 (GLP1), decrease after a loss of just 5 to 10 percent of body weight,” she says. “At the same time, the opposite happens with appetite-inducing hormones, like ghrelin, which grow in strength when you lose weight. These hormones are a big component of why it’s so hard to keep weight off.”

Sean Algaier went from 444 pounds to 289 at the show’s finale; he now weighs 450. (Photo: Before: Chris Haston/NBC Universal via Getty; After: Trae Patton/NBC Universal via Getty)

Experts stress that this study is not a reason to believe you are doomed to be overweight for life, or that no weight-loss programs are effective. Researchers do need to keep examining potential avenues for extended weight maintenance.

In the meantime, Lofton thinks it’s important to understand phenomena happening in your body. “I always make patients aware,” she explains. “Inevitably, if they put some weight back on, they’ll think they have no willpower or that they’re cheating on their programs. So I let them know that they’re in a vulnerable state for weight regain.”

Lofton also suggests becoming intimately familiar with your personal BMR. Like the contestants in the study, who were dramatically far from averages, you cannot guess your own number based on a simple calculation. “You can sometimes get a reading at the gym or, if not, at a doctor who deals with weight loss,” she says. “It is both age-specific and you-specific.”

To keep the weight off, Lofton has patients eat to their BMR in net calories — so if you have a resting metabolism of 1,500 calories and burn 300 through exercise, you can eat 1,800 calories a day. If this is not a sustainable number of calories, or the patient is having trouble with regain, Lofton says that medical management is useful, and there are medications that can help prevent the pounds from coming back. (See your doctor for help with this.)

Srinath says that once you enter maintenance mode, you still need to keep the mindset that you are on a regimen. Stay the course with a healthy diet and exercise, and avoid indulging or slacking as a prize for reaching your goal weight. “Because the resting metabolism slows as we lose weight, any extra calories do add up,” she says. “Exercise also plays a crucial role in helping to raise metabolism and maintain lean body mass — a combination of cardio and resistance training, at least 30 minutes, five days a week.

But beyond the reduction in metabolic speed, it’s crucial to realize that there is a psychological component at play, according to Deena Adimoolam, MD, an assistant professor of diabetes, endocrinology, and bone disease at the Icahn School of Medicine at Mount Sinai.

“I always explain to patients that they are in a constant battle with their mind and body due to the hormonal changes associated with weight loss,” Adimoolam tells Yahoo Beauty. “Their body has maintained a certain size for many years, and their body wants to do everything to go back to the weight it used to be. They need to constantly say no to cravings and understand the difference between true hunger and habitual eating.”

Your body will try to trick you. “I work with patients to establish their daily caloric needs to maintain their normal bodily functions and then teach them how to calorie count and estimate the calories that are in the foods that they consume,” Adimoolam says. “Patients will tell me that they are ‘starving,’ throughout the day with just three to four meals — even though they are consuming the exact calories that their bodies need.

She teaches patients to drink a cup or two of water instead of immediately eating, until the body realizes it’s not starving and not getting more food. “You want to trick the brain into thinking it’s full or satisfied,” she says. “The trick is to outsmart one’s own body and mind — and just say no.”

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