Both high- and normal-protein diets are effective for weight loss in adults with Type 2 diabetes

Reviewed by Megan Craig, M.Sc.Sep 12 2023

New findings from the University of Alabama at Birmingham indicate that the type of protein in the diet is not as important as the overall amount of weight loss for those with Type 2 diabetes.

Published in the journal Obesity, 106 adults with T2D were randomly assigned to either the high-protein or normal-protein diet for 52 weeks. Both diets were energy-restricted. The high-protein diet included recommendations to include lean beef in the diet, while the normal-protein diet instructed participants to refrain from eating any red meats. The team of researchers found that both a high-protein diet (40 percent of total calories from protein) and a moderate-protein diet (21 percent of total calories from protein) were effective in improving glucose control, weight loss and body composition in people with Type 2 diabetes.

Lead author James O. Hill, professor with the UAB Department of Nutrition Sciences and director of the UAB Nutrition Obesity Research Center, and co-author Drew Sayer, Ph.D., with the UAB Department of Family and Community Medicine, say that in this context of comparing two overall healthy dietary patterns that differ in the amounts of dietary protein and carbohydrate, as well as the inclusion/exclusion of lean, minimally processed beef, the results here show an individual can have some flexibility to choose a dietary pattern that most closely matches their preferences and that they are mostly like to stick with in the long term.

In the multi-site, randomized controlled trial, 71 study participants followed a higher-protein diet with four or more 4- to 6-ounce servings of lean beef per week (as the only source of red meat) or a normal-protein diet with no red meat, for 52 weeks. The high-protein diet was composed of 40 percent protein, 32 percent carbohydrate and 28 percent fat of total energy -; while the normal-protein diet was composed of 21 percent protein, 53 percent carbohydrate and 26 percent fat of total energy (which is higher in protein than the average American diet, with protein intake averaging 14-16 percent of total energy).

All participants had T2D and followed the State of Slim weight management program, with both diets being reduced in calories and limited to food lists for each phase of the SOS program. In addition, participants worked up to exercising up to 70 minutes per day, six days per week.

The study was funded by the National Cattlemen's Beef Association, a contractor to the Beef Checkoff, which was not involved in the study design, interpretation or publication.

Study key points

• Both a high-protein diet that includes red meat and a normal-protein diet without red meat are effective for weight loss and improving blood sugar control.
• The primary factor in managing Type 2 diabetes is weight loss itself, regardless of the specific composition of the diet.
• Avoiding red meat does not provide any additional benefits for weight loss or blood sugar control during a weight loss program.