Study Finds Intermittent Energy Restriction Most Effective for Type 2 Diabetes

New Delhi: A new study has found that different dietary strategies—intermittent energy restriction (IER), time-restricted eating (TRE), and continuous energy restriction (CER)—can all help improve blood sugar levels and aid weight loss in people with obesity and type 2 diabetes. However, IER showed the most promising results in several key health areas.

Unlike intermittent fasting, which often involves complete or near-complete abstinence from food for specific periods, IER focuses on reducing calorie intake during certain days of the week. In this study, researchers directly compared the popular 5:2 IER method with a 10-hour TRE plan, where food intake is limited to a 10-hour window each day.

Conducted at The First Affiliated Hospital of Zhengzhou University in China, the study involved 90 adults with type 2 diabetes and obesity. Participants were randomly placed in one of three groups: IER, TRE, or CER. All groups followed a similar weekly calorie intake, and a team of nutritionists closely monitored the 16-week intervention.

Out of the 90 participants, 63 completed the study. On average, participants were 36.8 years old, had been living with diabetes for 1.5 years, had a BMI of 31.7, and an initial HbA1c (a measure of long-term blood sugar control) of 7.42%.

By the end of the trial, all groups saw improvements in weight and HbA1c levels. However, those in the IER group had the greatest overall improvements, including a larger drop in fasting blood glucose and triglyceride levels and better insulin sensitivity (measured by the Matsuda index). Importantly, IER also had the highest adherence rate at 85%, slightly ahead of CER at 84% and TRE at 78%.

Mild hypoglycemia occurred in a few participants—two in the IER and TRE groups and three in the CER group—but no serious side effects were reported. Uric acid and liver enzyme levels remained stable across all groups.

Dr. Haohao Zhang, the lead researcher, highlighted that these results provide valuable insights for healthcare professionals when deciding on the best dietary approach for patients with obesity and type 2 diabetes.

The study was presented at ENDO 2025, the annual meeting of the Endocrine Society, currently taking place in San Francisco, USA.