It's a sad, well-worn fact that 90 percent of folks who lose weight fail to keep the pounds off. That abysmal success rate has left nutritionists scrambling to figure out how to help dieters maintain their weight loss without feeling like they have to stay on a "diet" in perpetuity. Well, a new study published in the New England Journal of Medicine may provide a template for post-dieters to follow. It turns out, those who fill their plates with more protein and fewer processed carbohydrates—not all carbs are created equal—are better able to maintain their weight loss than those who eat a similar number of calories but shun protein for pasta, bagels, and bread. Processed carbs, often packed with sugar and white flour, fall into the category of high-glycemic index foods because they cause a rapid spike in blood sugar levels, which promotes the storage of body fat. "The results indicate that even a modest increase in dietary protein or a modest reduction in glycemic-index values was sufficient to minimize weight regain and promote further weight loss in obese patients after a successful weight-loss diet," write the Danish study authors.
The study included nearly 800 overweight volunteers who lost an average of 23 pounds by following a low-calorie diet and were then randomly assigned to one of several eating plans in an effort to prevent weight regain over six months. Weight regain was less in those assigned to eat higher amounts of protein and "low-glycemic index" carbohydrates like high-fiber fruits, vegetables, and whole grains compared to those who were told to eat less protein and more high-glycemic index foods like white rice, French fries, and sugary cereal. Those who ate more protein also were more likely to continue losing weight than those who ate mostly carbohydrates, even the unprocessed ones.
These findings aren't so surprising to Tracy Cherry, a registered dietitian and clinical nutrition specialist at the University of Rochester Medical Center, given how differently the body handles protein and carbohydrates. While carbohydrates cause blood sugar spikes, protein doesn't have this effect, so it's not as likely to increase body fat when consumed in reasonable amounts. Low-glycemic index, unprocessed carbohydrates, which are digested more slowly due to their fiber content, tend to cause more modest blood sugar surges, which explains why they're better at promoting weight maintenance than are high-glycemic carbs. Still, Cherry says she's encouraged by the news: "We know a lot about what it takes to lose weight initially but not a lot about keeping weight off," she says. "I can take this study and provide meal plans for my patients."
If you've recently lost weight, here's what Cherry recommends to keep the pounds off:
1. Make changes you can stick with. The word "diet" implies something that will end, so the post-diet habits you follow should be maintainable. "If you really like cookies or ice cream, schedule them in once or twice a week so you don't feel too deprived," says Cherry. Include a serving of lean protein—egg-white omelette, fish, skinless chicken breast, low-fat cheese, tofu—with every meal and snack to help keep your blood sugar levels steady and to keep you feeling fuller longer.
2. Think whole foods. "Foods in boxes tend to be processed, so you're better off choosing [single]-ingredient foods like fruits, vegetables, skim milk, and fish," rather than multiple-ingredient products that come in cardboard or a can, says Cherry.
3. Read the labels of packaged foods. No question, that frozen dinner sometimes is a necessity, but some versions are better than others. Amy's, Kashi, Morningstar Farm, and Boca tend offer less-processed, high-fiber meal options. Still, you really need to check the labels for ingredients, says Cherry. "It should have a fiber content that's 15 to 20 percent of the daily recommended amount, and it should have less than 10 percent of your daily maximum of saturated fats." The daily max for saturated fats is 20 grams. Whole-wheat products, she adds, should be made with 100 percent whole wheat not just wheat flour; this will ensure their carbohydrates are lower on the glycemic-index scale.