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We’re All the Biggest Loser: Metabolic Responses to Drastic Weight Loss

For people who are extremely overweight, a program of diet and exercise may seem like a healthy way to effect drastic weight loss. However, there have been multiple studies conducted on the contestants on the popular reality TV show “The Biggest Loser” that debunked this myth1.

In the same way, you might think that the low-carb keto diet you’ve been strictly adhering to has helped you lose weight quickly. There are a variety of quick weight loss methods, but are they sustainable?

This article reviews a study on the popular reality TV show “The Biggest Loser” to understand our body’s response to drastic weight loss.

The Biggest Loser

The Biggest Loser is an American competition reality show that ran on NBC for 17 seasons from 2005 to 2016. Contestants competed to lose the most percent of their initial weight and win a cash prize.

It seemed to offer tremendous hope for people who struggle with obesity. The contestants, many with a BMI of 40 or greater, competed to lose weight in a short amount of time. They worked with doctors, nutritionists, and personal trainers. Those who lost the most weight during the 30 week TV season won the competition.

The participants rapidly lost massive amounts of weight, primarily from body fat mass (FM) with relative preservation of fat-free mass (FFM)2.

Study Findings

In 2016, researchers followed 14 contestants during and after one season of the show. Contestants experienced drastic weight loss, losing an average of more than a 100 pounds each. By the final weigh-in, contestants’ leptin levels had plummeted. They had very low levels of the hormone, rendering them constantly hungry. They also reported having a slow metabolism. In other words, their thyroid function – which governs metabolism and many other bodily functions – had slowed.

Leptin: Leptin is a hormone that prevents hunger and regulates energy balance. In other words, your body does not trigger a hunger response when energy isn’t needed.

Over the following six years, the combined effects of these hormonal changes caused the contestants to regain much, if not all, of the weight they had lost on the show.

Fasting Plasma Hormones and Metabolites

It was interesting to see that leptin and metabolism never returned to what they were before the show. After six years, plasma leptin, the thyroid hormone, and thyroxin (T4) remained lower than baseline.

Interestingly, insulin sensitivity was not significantly improved six years after the competition compared with baseline despite significant sustained weight loss.

Persistent Metabolic Adaptation

Despite the substantial weight regain in the 6 years following participation in “The Biggest Loser”, Resting Metabolic Rate (RMR) remained suppressed at the same average level as at the end of the weight-loss competition. Mean RMR after six years was 500 kcal/day lower than expected based on the measured body composition changes and the increased age of the subjects.

Weight Gain Singapore

However, “The Biggest Loser” participants with the most weight loss at the end of the competition also experienced the greatest slowing of the RMR at that time4. Similarly, those who were most successful at maintaining lost weight after six years also experienced significant ongoing metabolic slowing.

These observations suggest that metabolic adaptation is a proportional, but incomplete, response to reduced body weight from its defended baseline or “set point” value3.

Losing a Key Hormone

However, the contestants didn’t gain weight solely because of their slowed metabolism. They constantly battled hunger, cravings, and binges. The investigators found at least one reason: plummeting levels of leptin. The contestants started out with normal levels of leptin.

But by the season’s finale, they had almost no leptin at all, which made them ravenous all the time. As their weight returned, their leptin levels rose, but only to half of what they had been. This helped explain their constant urges to eat4.

This increases overeating due to the permanent reduction of leptin levels as a result of drastic weight loss.

A Basic Biological Reality: Overeating is a Natural Instinct

The difficulty in losing weight is not due to a pathological lack of willpower, as widely believed, but rather to biology. Overeating is in fact a natural instinct. Thousands of years before cars or phones, our ancestors did not have an abundance of food.

They were hunters/gatherers and, who sometimes had plenty to eat but regularly endured periods of time where food was scarce. This selective pressure forced our bodies to develop an almost unlimited ability to shore up excess energy in the form of body fat, and very adaptive metabolisms to conserve energy.

Overeating Food

This “survival mechanism” now backfires in a world where food has become so accessible. Adaptations that helped our ancestors survive are now causing us to overeat in a world where food abounds.

Dangers of Drastic Weight Loss

In spite of how tempting it may be to try and lose weight fast, the study conducted on The Biggest Loser has shown that this is not recommended. Diets that promote rapid weight loss are often very low in calories and nutrients. This may put you at risk of many health problems.

The Biggest Loser showed that even if the contestants initially showed results, their bodies battled back for years. There is no doubt that a few exceptional individuals can ignore primal biological signals. But for most people, the combination of incessant hunger and slowing metabolism is a recipe for weight regain.

This is why so few individuals can maintain weight loss for more than a few months.

Targeting Fat, Not Muscles

When we lose weight, we want to get rid of true adipose tissue. Not muscle mass. From what we have seen above, drastic weight loss plans are not only unsustainable but can lead to permanent negative changes to the body. In addition, it causes muscle breakdown instead of fat.

While that may be the case, there are some alternatives that are available that can get to the root of the problem. FDA-approved non-invasive fat removal treatments such as CoolSculpting and SculpSure can effectively target stubborn fat cells that are resistant to any form of dieting and exercise.


This non-invasive fat removal treatment uses cyrolipolysis, also known as fat freezing, to effectively target adipose tissue by inducing cell death.

Cryolipolysis is a non-surgical treatment and doesn’t use needles. During the procedure, the targeted area of fatty tissue is treated using a vacuum suction applicator that cools the fat cells. Under temperatures that fall as low as -13°C, the adipose cells suffer cell death and are broken down without damaging the surface of the skin.

Following the treatment, the broken down fat cells are then expelled from the body via the lymphatic system. Cryolipolysis can remove up to 27%* of fat in a single session.

CoolSculpting Singapore | Ensoul Body Medical Clinic


SculpSure is a laser-based, non-invasive fat removal treatment also meant to target and eliminate stubborn fat pockets. Using laser lipolysis, SculpSure is able to penetrate deep into the dermis to cause a breakdown of adipose tissue.

During the treatment, the SculpSure applicators are strapped onto the targeted area. The applicators deliver 1060nm diode laser beams that reach temperatures up to 47°C.

Under these temperatures, the fat cells underneath the skin are broken down without damaging other tissues. After the procedure, the broken down fat cells are then disposed of by the body.

SculpSure Singapore | Ensoul Body Medical Clinic

Lesson learned

The biggest takeaway from what we’ve observed in the contestants of The Biggest Loser is that drastic weight loss is never a good option. Whether you’re looking to lose 5kg or 20kg, slow and steady is a far more sustainable option. Gradual weight loss doesn’t cause extreme changes in hunger hormones and the slowing of metabolism as seen with the contestants on the show.

However, if you’re looking for a solution to the pockets of stubborn fat that have been resistant to all forms of exercise and dieting, non-invasive fat removal treatments are an option to consider.

Schedule an appointment for a detailed body assessment to determine which treatment option would be best for you.