New research suggests that eating less just two days a week could be more helpful than other popular diet plans for people with obesity and type 2 diabetes.
The study, which will be presented at ENDO 2025—the Endocrine Society’s annual meeting in San Francisco—compared three types of diets: intermittent energy restriction (IER), time-restricted eating (TRE), and continuous energy restriction (CER).
The researchers found that all three approaches helped reduce blood sugar levels and body weight, but the IER method seemed to offer extra benefits.
In the IER group, participants followed a 5:2 pattern, where they ate significantly fewer calories on two non-consecutive days each week and ate normally the other five days.
This method improved fasting blood sugar, insulin sensitivity, and triglyceride levels more than the other two diets. It also had the highest rate of participants sticking to the plan.
“This is the first study to directly compare the effects of these three diets in people who have both obesity and type 2 diabetes,” said lead researcher Dr. Haohao Zhang, a chief physician at The First Affiliated Hospital of Zhengzhou University in China.
“The results give doctors more evidence to guide dietary recommendations for their patients.”
The clinical trial included 90 participants with an average age of 36.8 years, a diabetes duration of 1.5 years, and a starting BMI of 31.7. Each person was randomly placed into one of the three diet groups and followed for 16 weeks. Nutritionists helped monitor and guide the participants throughout the study. In the end, 63 people completed the trial.
Although all groups showed similar reductions in overall blood sugar (measured by HbA1c) and weight, the IER group showed the largest drop in both areas. It also had better outcomes in fasting blood glucose, triglycerides, and insulin sensitivity.
Mild cases of low blood sugar occurred in a few participants from each group, but no serious side effects were reported. Adherence to the diets was also highest in the IER group at 85%, compared to 84% in the CER group and 78% in the TRE group.
Dr. Zhang believes the findings support the idea that intermittent energy restriction is not only safe but may be especially effective for managing diabetes and obesity. The full study will be presented on July 13 under the title: “Intermittent versus Time-Restricted or Continuous Calorie Restriction for the Management of Obesity with Type 2 Diabetes: A Randomized Clinical Trial.”
Copyright © 2025 Knowridge Science Report. All rights reserved.
