Soy versus milk based "meal replacements" for weight loss

In a recent study, of overweight men and women, researchers compared the weight loss and blood lipid effects between reduced-calorie milk- and soy-based beverage meal replacements. After 12 weeks on a 1,200-calorie per day diet which included 2 to 4 soy- or milk-based meal replacements, men and women in both groups lost about 8-9 % of their initial body weight. However, people who consumed the soy-based meal replacements experienced significant decreases in total and LDL cholesterol as well as triglycerides compared to people on the milk based meal-replacements . This study confirms previous studies documenting the effectiveness of meal replacements for weight loss but this study also showed that soy based meal replacements have the added benefit of lowering blood fats.

Meal replacements can be helpful in the short term to help people reduce their energy intake for weight loss but a long-term successful weight loss plan should contain a variety of food, be low in saturated fat and calories, and high in nutrients and include at least 30-60 minutes/day walking.

Weight loss and lipid changes with low-energy diets: comparator study of milk-based versus soy-based liquid meal replacement interventions. Anderson, J. W., Hoie, L. H., Journal of the American College of Nutrition 2005 Jun;24(3):210-216

Meal replacements - do they work?

A recent meta-analysis published in the International Journal of Obesity and Related Metabolic Disorders May 2, vol 27 (5) 2003 (pages 37-49) by Heymsfield et al showed that meal replacements result in medically significant weight losses - 7% average weight loss at 3 months and 7-8% at 1 year. Along with the weight loss there was also an improvement in some heart disease and diabetes risk factors such as blood glucose and insulin levels, blood lipid profiles and blood pressure.

Two groups of dieters were studied. The partial meal replacement (PMR) group replaced 1-2 meals daily with 1-2 vitamin/mineral fortified liquid meal replacements but included at least one meal of regular foods. The reduced calorie diet group (RCD) consumed the same number of calories as the PMR (800-1600kcal/day) but did not consume any meal replacaments. A significantly greater weight loss was achieved in subjects receiving the meal replacements compared with the RCD group. The former lost 7-8% body weight and the latter 3-7% i.e the PMR group lost 2.5kg more. There were also significantly less dropouts in the PMR group after 1 year. No reported adverse events were attributable to either weight loss regimen at one year.

Last Updated: November, 2003.