Star ratings reflect scores of 1 to 5 assigned to Slim-Fast in seven categories by nutritionists, specialists in diabetes and heart disease, and other diet experts on a ratings panel assembled by U.S. News. (See our Best Diets methodology.) The diet was judged as relatively well-designed to produce both short- and long-term weight loss, and according to experts, it’s relatively nutritionally sound and safe. It offers structure and convenience, but Slim-Fast products could grow old after a while, making long-term adherence difficult. Below, ratings in all categories and how the experts’ opinions broke down.
Short-Term Weight Loss
Slim-Fast will likely deliver fast results thanks in large part to its 1,200-calorie-a-day regimen. It earned nearly 3½ points out of 5, topping many other ranked diets. Experts said it’s an effective way to lose weight in the short term.
Long-Term Weight Loss
Slim-Fast is a sustainable diet, according to experts, and there’s a decent chance dieters will maintain significant weight loss for two years or more. The popular meal-replacement program pulled in more than 3 out of 5 possible stars, outperforming a large majority of other diets.
Easy to Follow
Slim-Fast takes the guesswork out of dieting. Grab a meal bar or shake and you’re good to go. While the products could grow repetitive, you can spice things up with restaurant meals and the occasional splurge. “This plan makes living a normal life outside of a can or bar difficult,” according to one expert. Still, it outshined many competitors in this category.
Slim-Fast conforms relatively well to government nutritional recommendations, and experts gave it middle-of-the-road reviews on how nutritionally sound it is. The company’s products are packed with various nutrients, but dieters only get a low 1,200 calories a day.
Slim-Fast pulled in its highest score in the safety category. Health risks, like malnourishment and excessively rapid weight loss, aren’t major concerns. Nevertheless, dieters under the age of 18 should steer clear, experts said, because 1,200 calories a day isn’t appropriate for children and young adults who are still growing.
Slim-Fast earned more than 3 out of 5 stars from experts, consistent with research suggesting it can help prevent or manage diabetes. The program has been described as a safe and effective way to improve glucose and insulin levels, which are important measures for diabetics.
For Heart Health
Slim-Fast received its worst score in the heart category. At best, the program is likely to have a modest effect on cardiovascular health, according to experts. Still, some research suggests meal-replacement diets can help lower total and LDL cholesterol, as well as blood pressure. When these levels are high, the risk of heart problems increases.
Last updated by Angela Haupt | December 12, 2013