It's still a low-cal diet with its own line of packaged foods, but today's NutriSystem plan is different from what it was 10, 20, or 30 years ago. These days, the emphasis is on choosing "good carbs" over bad ones, using a ranking system called the glycemic index (G.I.) as a guide. Another change: Rather than driving to weight-loss centers in strip malls for face-to-face advice, dieters chat with counselors and order foods online. The same program is also outlined in the book NutriSystem Nourish: The Revolutionary New Weight-Loss Program (John Wiley & Sons, 2004). Variations are available for women, men, vegetarians, and people with type 2 diabetes.

There's a single-serve sloppy joe mix that you reconstitute with water and heat. Spaghetti with sauce pours out of a nonrefrigerated foil pouch. Asian noodles come in a cardboard soup bowl; just add boiling water. If it sounds a little like military rations, that's pretty close to the mark. And chances are many dieters will be bored with eating the same not-so-great-tasting foods meal after meal. Yet for other folks, the convenience might outweigh the blandness, and the low-calorie program does help peel off pounds. The big concern among health professionals: Once you're no longer relying on prepackaged foods to count calories and measure portions for you, can you maintain your weight in the real world?

Basic principles:

Dieters learn to make weight loss their number-one priority. Good carbs, i.e., those with low G.I.'s (such as whole-grain breads and fiber-rich veggies), are the fuel of choice. That's because they maintain normal blood sugar and insulin levels, resulting in less hunger and fat storage. Low-fat proteins such as lean meats, fish, and calcium-rich dairy products are also OK. Bad carbs-such as those found in sodas and processed white bread-send blood sugar levels into the stratosphere and are strictly taboo. The program includes advice about keeping active, reducing stress, and mentally visualizing success.

How the diet works:

Forget counting calories, or even worrying about the glycemic index. Dieters who buy the company's prepared foods automatically receive correct portions in the form of low-G.I. foods. The plan adds up to one low-fat protein at each meal, three daily servings of vegetables, two to three fruits, two to three dairy products, two to four whole grains, and one to two servings of heart-healthy fats.

What you can eat:

Banana Spice Muffins. Apple Cinnamon Soy Chips. Vegetarian Sloppy Joes. There's a whole list of prepackaged meals and snacks to buy either online or from the QVC shopping channel. Fruits, veggies, and dairy products from your local market supplement the plan. While it's possible to follow the diet without NutriSystem foods, it's obvious the company makes a lot of its money from selling these products.

Does the diet take and keep weight off?

Not conclusive. After 30 years in the business, NutriSystem can't point to a single clinical trial to demonstrate that this diet works. The book and Web site do offer anecdotal success stories, but the long-term effects of eating premeasured, prepackaged foods are unknown.

Is the diet healthy?

Mostly. One concern: A special three-day BodyBoost plan used to break a dieting plateau averages out to only about 1,000 calories a day, too few calories to provide all the nutrients you need. Plans that call for 1,200 calories or more based on weight, gender, and activity level should work just fine.

What do the experts say?

"I'm not convinced that the glycemic index is the be-all and end-all for weight loss," says registered dietitian Leslie Bonci, director of sports-medicine nutrition at the University of Pittsburgh Medical Center. In fact, Bonci thinks it's probably the low-calorie nature of this diet that's helping dieters shed pounds. "These portions are very small," she says of the daily meal plans. "Two ounces of turkey, some sliced cucumber, and wheat bread is not a lot of food." And she worries that the calorie count may be too low for some people.

Dee Sandquist, RD, a spokeswoman for the American Dietetic Association and director of the Center for Weight Management at Southwest Washington Medical Center in Vancouver, thinks the diet could hold benefits for a select group. "For someone who likes structure and doesn't like to cook, this program may help jump-start weight loss," Sandquist says. The danger, she adds, is that it's easy to gain the weight back. Without the program and company foods, Sandquist feels dieters could be at a loss about how to eat.

Who should consider the diet?

Dieters who thrive on packaged convenience foods. Anyone who craves the fresh taste of pan-sauteed fish, roasted chicken, or a sizzling steak right off the grill, though, isn't going to be wowed by the taste of freeze-dried scrambled eggs.

Bottom line:

It's a shame the food can't taste better, especially since it's so expensive. Overall, though, the plan seems nutritionally sound, albeit a bit low in calories to be realistic for many dieters. And once the diet is over, it's easy for the weight to come back.
Back to Diet Guide