Why Is It So Difficult to Maintain Weight Loss?

By Nicole Kofman

Disappointing lessons from “The Biggest Loser” participants’ experiences six years later.

Not only is it difficult enough to lose weight in the first place, but it can also be just as – if not more – challenging to keep it off.  Dozens of weight loss studies show that participants can experience initial success when it comes to losing weight, but over the course of five years (or even just one year), many struggle to maintain that level of weight loss. The New York Times recently highlighted a small, fascinating study examining the weight loss and metabolism of 14 participants from The Biggest Loser, a reality TV show in which obese participants compete to see who can lose the most weight. The participants lost an impressive 50-240 pounds while on the show. Unfortunately, six years later, only one of them has maintained his weight loss naturally (one participant has maintained it after having bariatric surgery). The rest gained much, if not all, of the weight back.

Why did so many people gain the weight back?

The study found that participants’ resting metabolic rate – the rate at which they burn calories while at rest – decreased significantly at the end of the show and slowed down even more over the six years that followed. For instance, one participant was burning 800 fewer calories a day than a man of his size would be expected to burn. Ultimately, this negative change in resting metabolic rate played a role in most participants gaining back the weight they had lost six years prior.

Put differently, the body quickly reacts against losing weight by reducing the amount of energy that it burns – and that makes it harder to keep weight off and easier to gain it back.

The study is limited by its small sample size and the lack of a control group, but it vividly highlights how complex weight loss is. While people can control how much they eat, they can’t significantly control how much their body wants to hold onto each of the calories ingested. Shows like “The Biggest Loser” make weight loss look unrealistically simple – just eat less and exercise more and the weight will disappear – but this work shows it’s not that simple. This study also reminds society that weight gain is not personal failure; when you combine super easy access to high calorie foods and snacks with a biology that resists weight loss, it’s hard to win.

Additionally, participants in the study developed hormone imbalances that led to a decrease in leptin, a hormone that signals to the brain when the person is full, making them feel hungrier than the average person. This combination of feeling hungrier and burning fewer calories is a “recipe for weight gain,” in the words of Dr. David Ludwig, the director of the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital.

Bright Spots and Looking Ahead

Although the participants were unable to keep off the level of weight that they lost on the show, 57% of them did maintain at least 10% weight loss from their initial body weight (i.e., starting at 250 pounds and keeping off at least 25 pounds). Only 20-40% of participants in other weight loss studies have succeeded in maintaining 10% weight loss after one, three, and eight years.

Another upside of the study’s results is that hopefully, it can help defeat some of the stigma, shame, and blame associated with obesity in our society and encourage more research in this area. These results make it clear that weight gain trends “reflect biology, not a pathological lack of willpower,” as Dr. Michael Rosenbaum, an obesity researcher at Columbia, said in the NYT article. The study also indicates a need for researchers to target these challenges and develop drugs that can trick the brain into increasing its metabolism and not feeling constantly hungry. Currently, bariatric surgery has been demonstrated to be effective in helping people maintain an average of 47% weight loss, though surgery comes with greater risk, financial burden, and permanent changes.

What are some proven weight loss strategies?

While we have yet to crack the code for extreme weight loss maintenance, studies show that losing and maintaining just 7% of one’s weight and increasing physical activity can reduce someone with prediabetes’ chance of developing type 2 diabetes by 58%. “The Biggest Loser” is an extreme example of a weight loss regimen that is not possible or healthy for most people; fortunately, there are examples of realistic programs that are successful in helping participants lose weight:

• Commercial weight loss programs, such as Weight Watchers and Jenny Craig, help participants lose an average of 2.6 – 4.9% of their body weight. That means if someone weighs 250 pounds, they can lose an average of 6 – 12 lbs through these programs.

• The Diabetes Prevention Program (DPP) has been proven to help participants lose an average of 2.4% of their body weight. That means if someone weighs 250 pounds, they can lose an average of 6 lbs through the DPP. Find a DPP near you here.

• Online DPPs like Omada Health and Canary Health can be more convenient for people than in-person programs. Omada Health has been proven to be effective for losing an average of 4.3% body weight after two years.

• Obesity drugs like Saxenda  Contrave, Qsymia, Belviq, Orlistat, and Qnexa help people lose, on average, 5-10% of their body weight.

• One side effect of type 2 diabetes drugs metformin, SGLT-2 inhibitors, and GLP-1 agonists is mild to moderate weight loss.

Read the full article covering this study in The New York Times here.