On May 2, 2016, the journal Obesity published a study that followed 14 previous contestants from the NBC weight-loss reality show, The Biggest Loser. The New York Times and other media outlets covered the story in-depth, interviewing the stars and doing photo spreads. The messages in the headlines (weight loss wrecks your metabolism and no one can maintain weight loss) were quite different from the facts.
What are the facts of the study?
- On average, the 14 contestants lost 39 percent (about 128 lbs) of their body weight over the 7 months of the show, which is an average loss of 4 lbs/week.
- Over the following 6 years, contestants regained an average of 90 lbs.
- One of the suspected reasons for the weight gain came from measurements of the contestants’ resting metabolic rate (RMR), or how many calories your body needs per day to function. Smaller bodies burn fewer calories than bigger bodies, so as weight decreases, daily calorie needs, or RMR, decreases.
- On average, the contestants’ RMR decreased by 23 percent (610 kcal/day) at the show’s end after 7 months.
- However, over the next 6 years as the contestants regained weight, their RMRs did not bounce back, and decreased a bit more to be, on average, 27 percent (704 kcal/day) lower than when they started.
- In other words, 6 years after the show, the contestants’ daily calorie needs were about ~500 kcal lower than expected based on their body composition, and compared to someone else their size. This made them more susceptible to weight regain.
This study has been misinterpreted as evidence that:
1. Weight loss can lead to permanent damage to your metabolism (RMR and daily calorie needs).
2. No one can maintain his or her weight loss.
Which has led many to the conclusion that “there is no point in trying to lose weight, because even if I do lose weight, I will just gain it back, and my metabolism will be wrecked forever.”
What is the reality?
It is true that when you lose weight, your daily calorie needs decrease. That is why you see your Daily SmartPoints® Target and Weekly SmartPoints go down as your weight goes down. But decades of research have found that your daily calorie needs will not remain lower forever, but that your metabolism will bounce back if you experience some weight regain.
Here are some points to consider:
- This is one small study of 14 people who lost a large amount of weight quickly, and in an unusual way. The rapid rate, and extreme amount, of weight loss among The Biggest Loser contestants may, unfortunately, have put them at risk for the metabolic consequences that were observed in the study.
- Metabolism as it relates to weight loss, achieved at a safe rate and of a more typical amount (10 percent), has been studied for decades. While metabolism declines when people lose weight, there’s plenty of evidence that says the typical change is nothing like what was shown in this study. Additionally, studies have found that if you gain some weight back, your metabolism will also bounce back. A great example of this is a study published in the New England Journal of Medicine in 1995, which measured the RMRs in 41 people as they lost and gained 10 percent of their body weight. The study found that daily calorie needs responded to change in weight, in both directions. For example, a 10 percent weight loss corresponded, on average, with a 9 percent decrease in daily calorie needs, and a 10 percent weight gain corresponded with a 14 percent increase in daily calorie needs. In addition, the study measured eight women at their initial weight, and again as they gained 10 percent, and then lost 10 percent of their body weight, and finally when they returned to their starting weight. There was no significant difference in the energy needs of the women at their initial weight or when they returned to that weight. In other words, there is no permanent “damage” to metabolic rate—just an increase when weight is gained and a decrease when weight is lost.
- We know that people can lose weight — and keep it off. Maintaining weight loss is a challenge, but it can be done.
The National Weight Control Registry, established in 1994, tracks the progress of 10,000+ people who have lost at least 10 percent of their body weight and kept it off for at least a year (the average registry participant, with a 72-pound weight loss maintained for 5 years, well exceeds that criteria). When asked what helps them keep the weight off, registry participants reported continuing the habits they established when they were losing weight, including keeping up their healthy eating, enjoying an hour of fitness a day, and continuing to weigh themselves. This is why Weight Watchers fundamentally believes in helping each one of our members to discover and adopt a healthy lifestyle that works for them — so that what you did to lose the weight is something you can live with to maintain your weight.
WW members have a wealth of resources, from delicious, low-SmartPoints recipes on ww.com to great strategies for healthy living in WW magazine. Not to mention one of our most powerful tools of all: the entire WW community of Coaches, Guides, and members in Studios and online — including the Connect feature on the WW app where you’ll find story after story and photo after photo of successful, positive people supporting each other on their unique weight-loss journeys. (And if you’d like some “anecdotal” evidence that WW members lose weight and keep it off, just ask any of our Coaches or Guides!)
A study like this — with small samples yet extreme results — can make waves in the media and encourage you to jump to conclusions about the end result of weight loss. As you can see, there’s more to the story, and you have more resources at your disposal than you might have thought to achieve—and maintain—a healthy weight. As always, WW will be here to help.