Science Shows Soy Helps With Weight Management

In the “battle of the bulge”, scientists have found protein-rich soyfoods may help individuals lose weight and fat when replacing other sources of protein in the diet. Soyfoods have the added benefit of lowering LDL (bad) cholesterol while aiding in weight control.

Dr. David Allison and Dr. Mark Cope at the University of Alabama at Birmingham, and Dr. John Erdman at the University of Illinois at Champagne-Urbana conducted an evidence-based review of studies on soy and obesity. The researchers found that soyfoods are equal to other protein sources, such as dairy or meat, in helping to battle weight by promoting fat loss.

The comprehensive review, published in the November issue of Obesity Reviews, looked at current research on animals, human populations, and clinical trials related to soy protein and weight control.

Researchers sought to determine the strength of the evidence on four proposed mechanisms by which soy may aid weight control:

  1. Soy increases weight loss when consumed at an equal calorie level as other foods.
  2. Soy aids weight and fat loss by decreasing caloric intake.
  3. Certain soyfoods benefit glucose control and heart health during weight loss.
  4. Certain soyfoods will minimize the loss of bone mass during weight loss.

The review, including results from eight human studies, found that individuals lost equivalent amounts of weight and, in some cases, equal inches of fat around the waist, using soy protein, dairy milk meal replacements, beef or pork at equal calorie levels. This illustrates the value of soy protein in a varied diet for weight control.

Findings also support the possibility that soy protein decreases short-term appetite and calorie intake. Follow-up trials are needed to confirm the role of soy protein in satiety, or the feeling of fullness.

Researchers also examined whether soy isoflavones reduce diabetes by stopping fat tissue build up and enhancing fat breakdown. Limited animal trials and human studies suggest soy-based diets and isoflavones may lower blood glucose and insulin levels. If proven effective, a soy-based meal replacement could provide additional benefits to diabetics during weight reduction.

Findings confirmed soy-based diets, compared to other low calorie diets, reduce LDL (bad) cholesterol and triglycerides and raise HDL (good) cholesterol. Findings indicate soy may reduce bone loss in women, but additional clinical trials on soy and bone loss are needed to confirm these results.

Let soy help in your weight loss battle and start gaining health. With a variety of healthy soy protein-rich soyfoods, it is easy to substitute soy for other forms of protein. For a list of soy-rich options, visit our Find a Product section.