Does exercise without dietary changes prevent diabetes?

Studies have shown that exercise combined with dietary changes helps prevent diabetes. Here, the two minute update looks at a study asking if exercise without dietary changes helps prevent diabetes.

This study included 220 people with obesity, 179 of which had 10 year follow-up Patients were randomized to a control group, or groups targeting moderate or vigorous exercise.

The vigorous exercise group patients received 5 sessions a week for a year with targeted heart rates for jogging or walking.

The moderate exercise group received pedometers and logged their daily exercise with a target of 150 minutes per week of brisk walking. At the end of 1 year, the exercise groups were instructed to continue their exercise regimens. All groups were instructed not to change their diet, and the control group was instructed not to change their exercise habits.

Adults in China age 40-65 were included, but they had to have central obesity based on waist circumference. The mean age was 54, and the mean hemoglobin A1c was 6.1%. There were multiple exclusions, including anyone with diabetes, chronic kidney disease, heart failure, or a myocardial infarction within 6 months.

At 10 years, the rates of diabetes were about 50% lower for both exercise groups compared to the control group. There was no difference between the moderate and vigorous exercise groups.

Waist circumference did fall in the exercise groups, but there was no significant difference in weight between any of the groups. It also would be great to see mortality data, especially at 15 or 20 years.

I don’t know about you, but I’ve never seen consistently good results when patients are told to lose weight. Maybe we would see better outcomes if we simply told patients to walk briskly for 150 minutes per week, and keep an exercise log.

Reference: Chen et al. Effect of Moderate and Vigorous Aerobic Exercise on Incident Diabetes in Adults with Obesity: A 10-Year Follow-up of a Randomized Clinical Trial. JAMA Intern Med 2023;183:1