Illustration by Tim Robinson for NPR
Illustration by Tim Robinson for NPR
Chances are that if you've ever lost weight following a strict diet and exercise regimen, you've also reached the diet plateau. On that lonely plateau, pounds never seem to melt away, no matter how hard you try to shed them.
You're not alone. Consider the plight of Susan Carierre. When the 5-foot-6-inch Carriere hit 230 pounds, she decided to enroll in a weight-loss program at the Pennington Biomedical Research Center near her home in Baton Rouge, La.
"My weight went up and down for years," says Carriere, 62. "I just couldn't keep it off." Over six months in the Pennington program, she finally dropped more than 50 pounds. "I was ecstatic," she says.
But then the scale got stuck at 181 pounds.
"It wouldn't move," Carriere says. "I was doing the same low-calorie diet, the same food every day and sticking to my daily walking." The scale stayed stagnant for weeks. "Why am I doing this? If I'm not making any progress, what's the point?" Carriere says she was thinking. "I might as well just go out for dinner, and if [my] husband is having fried food then I might as well have fried food!"
Carriere's frustration is echoed by most people, says Eric Ravussin, an obesity researcher who directs the Pennington center. There's no question there is a diet plateau, Ravussin says. "Four to six months into a diet program, this typically happens."
Even a weight loss of 10 pounds will set the body up to fight back. Ravussin says. Any significant weight loss means the body is smaller and needs less fuel to walk, go up stairs, jog or get out of a chair.
And less fuel burned means fewer calories needed. So if you've been on a diet of 1,500 calorie a day, perhaps your slimmer body now needs 300 calories less per day. That means you have to decrease your daily caloric intake — perhaps by as much as 300 calories, down to 1,200 calories a day — if you want to continue losing weight.
On top of that, metabolism slows as the body begins to combat what it interprets as potential starvation. So it begins to burn the calories it's getting more slowly. In Ravussin's research, he has found that metabolism slows even if dieters have maintained muscle mass. That's because the body is now using calories more efficiently. "It's like going from an old Ford to a Prius with a more efficient engine," he says.
And a more efficient engine isn't a bad thing. It means the body has adjusted to its new lower weight. "The diet plateau is the new set point," says Dr. Lee Kaplan, director of the Massachusetts General Hospital Weight Center in Boston. "So when you go to a healthier diet your body says 'Oh, this is good. Let's live at a lower body fat, and let's live at a lower set point.'"
The good news is that as long as people stick to the diet and exercise program that got them to the new lower set point, they'll maintain the new weight. But return to eating more and exercising less, and the weight will come back.
But what if you want to continue losing? What if the new set point isn't your goal? In the case of Susan Carriere, the 181-pound plateau was 20 pounds higher than her goal of 160 pounds.
"If you want to get below the new set point, you need a different approach added to the diet and exercise program you're already on," says Kaplan. "We call it speed dating obesity therapies," he says. "If one approach doesn't work, we try another one. We try a different diet. We add exercise or change the type of exercise. We encourage better sleep health. We encourage decreased stress."
Inadequate sleep and lots of stress often increase appetite and getting these things under control can help, Kaplan says. "We try to find the best therapies for each individual," he adds, stressing that everyone is different and may respond differently to various approaches.
But pretty much everyone agrees that exercise works for most people. That's because bigger stronger muscles burn more calories, says Kaplan. "If you're on the treadmill every day, you may burn a couple of hundred calories a day from being on the treadmill, but you may burn 600 or 800 extra calories throughout the rest of the day when you're not on a treadmill, because bodies with healthy muscles work better."
For some people, simply persevering through a diet plateau works eventually. That's what happened to Carriere who, after four weeks of not losing any weight, got on the scale one morning and had dropped three pounds. "It was like icing on cake," she says. "I mean, all of a sudden I feel like I rang the bell!"
But now that Carriere's body has adjusted to her smaller self, she'll lose weight more slowly than at the beginning of her diet. Unless, of course, she does something different. And that's exactly what she plans on doing. In addition to her daily walking, she'll add a Zumba exercise class. "It's the only thing that I've ever done that when you walk in, people are all smiling, and when you leave an hour later and you're sweating like an old dog, you're still smiling," she says.
Carriere's betting on the Zumba – and smiling — to help shed that final 20 pounds.