NutrisystemWith no long-term studies available, Nutrisystem wasn't ranked in the same fashion as the others. But Consumer Reports' editors found the program to be nutritionally sound in most regards, although high in sodium. On a taste test, Nutrisystem's 1,270 calories a day seemed to fall in the middle of the pack.
On the Nutrisystem diet, you eat branded single-serving breakfast, lunch and dinner entrees, all ordered online.
Overall score: Not rated
5. Atkins (tie)
The Atkins diet aims to force your body to burn fat, not carbs. But its focus on fatty foods (cheese, eggs, nuts) puts it outside federal nutrition guidelines.
Overall score: 48
5. Ornish (tie)
The Ornish menu is almost vegan, with no added sugars, and fat content so low that it falls outside nutritional guidelines. Ornish recipes are cleverly crafted and tasty, but require a fair amount of time and cooking skills.
Overall score: 48
The Zone diet uses "anti-inflammatory" meals and snacks with a ratio of 30 percent lean protein, 30 percent fat, and 40 percent low-glycemic carbs, in addition to nutritional supplements.
Overall score: 54
3. Weight Watchers
On Weight Watchers, you can eat whatever you want, as long as it stays within your personalized points quota. Weight Watchers offers substantial support online or with in-person group meetings, and highly encourages exercise.
Overall score: 57
On the Slim-Fast diet, you eat a Slim-Fast bar or shake for breakfast and lunch, and a 500-calorie homemade dinner, plus three daily snacks of fruit, veggies, nuts or a Slim-Fast snack bar.
Overall score: 63
1. Jenny Craig
Consumer Reports gave top honors to the Jenny Craig program. It offers branded single-serving entrees and other dishes, weekly support sessions with a counselor in person or by phone, and an emphasis on exercise. But the key to its victory was how well people stuck to the plan. A whopping 92 percent were still using Jenny Craig two years after joining, according to a study in the journal of the American Medical Association. Participants had lost an average of 8 percent of their body weight.
Overall score: 85