Best Commercial Diet Plans

If you’re considering a diet, brand-name programs like Weight Watchers, Jenny Craig and Slim-Fast might come to mind, but there are others. Experts who rated the 13 diet plans below for U.S. News found wide differences in effectiveness. Among the qualities considered by the experts were each diet’s ability to deliver weight loss, provide good nutrition and safety, and be relatively easy to follow.


Weight Watchers

(3.9 out of 5.0)

Weight Watchers recipes | Weight Watchers reviews

Weight Watchers is the top commercial diet, earning relatively high marks in all areas of assessment. Experts said it is safe, nutritious, and easy to follow. “In terms of commercial weight-loss plans, this is as good as it gets,” one said.

How the Weight Watchers Diet works


Jenny Craig

(3.7 out of 5.0)

Jenny Craig recipes | Jenny Craig reviews

Jenny Craig did almost as well. It garnered particularly good ratings from experts for enabling rapid weight loss and being easy to follow. Some experts criticized what they felt was overreliance on packaged meals, high cost, and challenges faced by followers in restaurants and other social dining situations.

How the Jenny Craig Diet works


Biggest Loser Diet

(3.6 out of 5.0)

Biggest Loser Diet recipes | Biggest Loser Diet reviews

Experts were impressed by the diet’s ability to deliver short-term weight loss and by its safety, nutritional soundness, and value as a diabetes or heart diet. They would have liked more information about effectiveness. “It’s hard to judge this diet based on very limited data,” said one expert.

How the Biggest Loser Diet works



(3.3 out of 5.0)

Slim-Fast recipes | Slim-Fast reviews

Slim-Fast ranked well against other commercial diets. “If you’re looking for quick, short-term weight loss, this is the perfect diet,” one expert said. “It takes all the ‘thought’ out of weight loss. You just have to drink the shakes.” That’s also a potential downside, since some panelists thought the diet can become monotonous and felt that dieters don’t learn how to eat for long-term weight maintenance.

How the Slim-Fast Diet works


Spark Solution Diet

(3.3 out of 5.0)

Spark Solution Diet recipes | Spark Solution Diet reviews

The Spark Solution, with its detailed playbook of meal plans and daily guidance, struck one panelist as “somewhat gimmicky.” However, the principals of the plan – nutritious eating and exercise – are tried-and-true methods for healthy eating and weight loss. So while a few experts agreed the plan is “nothing novel,” they still doled out scores that were higher than those of most other commercial diets.

How the Spark Solution Diet works


Flat Belly Diet

(3.2 out of 5.0)

Flat Belly Diet recipes | Flat Belly Diet reviews

The diet pulled in strong scores in nutrition, and safety. Experts rated it slightly above average for how easy it is to follow and slightly below average  for ability to prevent or manage diabetes and heart disease. One expert said the plan’s focus on eating a certain amount of monounsaturated fatty acids with each meal is based on “faulty logic.”

How the Flat Belly Diet works



(3.2 out of 5.0)

Nutrisystem recipes | Nutrisystem reviews

Nutrition, safety, and better-than-average ease of compliance are Nutrisystem’s strongest areas, according to experts. The diet’s scores in other categories were largely below average.

How the Nutrisystem Diet works


Abs Diet

(3.0 out of 5.0)

Abs Diet recipes | Abs Diet reviews

The Abs diet stands solidly in the middle of its commercial counterparts. While it incorporates “many of the principles for effective weight loss,” according to one expert, another commented that “there is no research behind this plan.” As a group, experts rated it near the back of the pack in ability to sustain long-term weight loss.

How the Abs Diet works


South Beach Diet

(3.0 out of 5.0)

South Beach Diet recipes | South Beach Diet reviews

Neither was South Beach a standout. While one expert called it a “healthier version of a carbohydrate-controlled diet,” and it received a high mark for short-term weight loss, panelists weren’t fond of its restrictive requirements. We found few studies that support claims of effectiveness.

How the South Beach Diet works


Zone Diet

(2.9 out of 5.0)

Zone Diet recipes | Zone Diet reviews

Experts found the diet mediocre relative to the other commercial programs. It emphasizes eating precise proportions of each type of calorie source—40 percent carbs, 30 percent protein, and 30 percent fat—an approach many experts dismissed as healthy but unrealistically demanding. As one put it, “research has not found anything miraculous in this nutrient breakdown.”

How the Zone Diet works

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Best Diets Rankings

Best Diets Overall
Diets ranked by across-the-board effectiveness.

Best Weight-Loss Diets
Diets ranked by effectiveness for both quick and lasting weight loss.

Best Diabetes Diets
Diets that can prevent diabetes or help diabetics.

Best Heart-Healthy Diets
Diets that lower cholesterol, blood pressure or triglycerides.

Best Diets for Healthy Eating
Diets ranked by how safe and nutritionally complete they are.

Easiest Diets to Follow
Diets ranked on whether they're a snap to stick to.

Best Plant-Based Diets
Plant-based diets ranked by overall effectiveness.

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