For people trying to lose weight, soy-based liquid meal replacement shakes may be just as effective as intensive behavioral therapy and more effective than weight loss medications, new research suggests.

“Using two meal replacements daily is one of the most effective ways of losing weight on your own,” said study author Dr. James W. Anderson.

What’s more, the benefits of soy-based meal replacements may extend beyond trimming the waistline, the report indicates. It also appears to help lower cholesterol and trigylceride levels.

“The bottom line is soy is healthy, and while incorporating it into weight loss may not have a more dramatic effect on your waistline than other nutrition plans, its benefits go beyond weight loss toward increasing overall health,” Anderson said in a university statement.

Obese individuals who follow very-low-energy diets have been shown to lose substantial amounts of weight and to maintain their weight loss. Further, recent interventions have shown that liquid meal replacements, or shakes, are also an effective means of weight loss and weight maintenance.

Anderson, and co-author Dr. Lars H. Hole, of NutriPharma in Norway, compared a soy-based liquid meal replacement, licensed by NutriPharma, and a milk-based liquid meal replacement in a 12-week study of weight loss among overweight and obese men and women.

Adults assigned to the soy group were instructed to consume five servings of Scan-Diet each day along with fruits and vegetables. Those assigned to the milk group were instructed to consume two servings of Slim-Fast each day along with fruits, vegetables and two servings of chicken breast, turkey or other lean meat.

Study participants were also asked to keep a record of their compliance with the meal-replacements as well as their food intake and level of physical activity.

Overall, the 30 participants who completed the soy intervention reported consuming about 3.7 shakes daily - 74 percent of the recommended amount - while the 22 participants who completed the milk-based intervention consumed about two shakes daily, as recommended.

Both groups achieved weight loss over the three-month study period, Anderson and Hole report in the Journal of the American College of Nutrition. Weight loss amounted to about 8.5 percent of initial body weight for all participants, and was not statistically different in the two groups.

This weight loss was equivalent to, or greater than, what would have been expected if they had participated in intensive behavioral intervention, the researchers note. And, they add, it was also about two times greater than the weight loss reported among individuals who use weight loss medications.

Men and women who used the soy-based meal replacements had consistently lower total cholesterol and LDL (“bad”) cholesterol levels than did those who consumed the milk-based meal replacements, the report indicates.

Further, the soy group experienced a reduction in their blood level of triglycerides, while there was no change among those in the milk group.

“Soy protein is very effective at lowering cholesterol,” Anderson said. However, he added, “Since milk-based shakes are almost as effective for weight loss and are better tolerated by many people, I let people make their choice.”

SOURCE: Journal of the American College of Nutrition, June 2005.