--- description: A study of Biggest Loser contestants finds that after weight loss, our metabolism slows, which is why it's so hard to keep off weight title: Why The Biggest Loser Contestants Gained Back the Weight image: https://static.time.com/v3/assets/bltea6093859af6183b/blt911a2d714bb15214/6987789d55a85942a4a85200/health-weight-scale-1.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  * [Health](/section/health/) ## Health Update your preferences in [Account Settings](/account/preferences/) Close * [Obesity](/tag/obesity/) ## Obesity Update your preferences in [Account Settings](/account/preferences/) Close # Why The Biggest Loser Contestants Gain Back the Weight by [Alexandra Sifferlin](/author/alexandra-sifferlin/) ## Alexandra Sifferlin Update your preferences in [Account Settings](/account/preferences/) Close May 2, 2016 3:15 PM CUT  Elizabeth Renstrom for TIME by [Alexandra Sifferlin](/author/alexandra-sifferlin/) ## Alexandra Sifferlin Update your preferences in [Account Settings](/account/preferences/) Close May 2, 2016 3:15 PM CUT It’s an unfortunate truth that many people who lose a significant amount of weight will gain it back. But a new study of contestants of the popular reality show _The Biggest Loser_ suggests that a slowed metabolism—not a lack of willpower—is largely to blame. In new research to be published in the journal _Obesity_, researchers followed contestants from _The Biggest Loser_ season 8 for six years to see what happened to them after they lost so much weight, the [New York Times reports](http://www.nytimes.com/2016/05/02/health/biggest-loser-weight-loss.html?%5Fr=0 "undefined"). Led by Kevin Hall, a scientist at the [National Institute of Diabetes and Digestive and Kidney Diseases](http://www.niddk.nih.gov/Pages/default.aspx "undefined"), the researchers found that people’s resting metabolism—how many calories they burn when they’re at rest—changes dramatically after weight loss. The men and women had normal metabolisms for their weight when they were obese, the _Times_ reports. However, once they dropped a massive amount of weight, their resting metabolisms slowed so significantly that they were not burning enough calories to maintain their new size. This is a normal reaction to weight loss; what was surprising was that as time passed and the people gained back weight, their metabolisms continued to slow, making the process harder. The winner of season 8, Danny Cahill, lost nearly 240 pounds in less than a year. Since then, he’s gained back 100 pounds, the _Times_ reports. But the findings may also apply to people who lose less. The new study adds to a growing body of research aimed at understanding why it’s so difficult for people to lose weight, and why some are more successful than others. Other [recent studies](http://time.com/4125083/why-losing-weight-is-hard/ "undefined") have suggested that people’s bodies respond dramatically differently to the same foods. In the future, weight loss advice may need to be more personalized, some experts suggest. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4314053/biggest-loser-weight-loss/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4314053/biggest-loser-weight-loss/"},"headline":"Why The Biggest Loser Contestants Gain Back the Weight","datePublished":"2016-05-02T15:15:51.000Z","dateModified":"2026-02-22T17:11:29.039Z","description":"A new study reveals why it's tough to stay lean after weight loss","url":"https://time.com/4314053/biggest-loser-weight-loss/","keywords":["Obesity","diet","Exercise","Weight loss","metabolism","lose weight","obese"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt911a2d714bb15214/6987789d55a85942a4a85200/health-weight-scale-1.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Alexandra Sifferlin","jobTitle":null,"url":"https://time.com/author/alexandra-sifferlin/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt911a2d714bb15214/6987789d55a85942a4a85200/health-weight-scale-1.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"TIME.com stock photos Weight Loss Health Exercise Scale","caption":"TIME.com stock photos Weight Loss Health Exercise Scale","creditText":"Elizabeth Renstrom for TIME","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/obesity/","name":"Obesity"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/4314053/biggest-loser-weight-loss/","name":"Why The Biggest Loser Contestants Gain Back the Weight"}}]}] ```