Study Examines 5:2 Fasting Diet's Effect on Glycemic Control in Diabetics

In a study published in the journal JAMA Network Open, researchers evaluated the effect of the 5:2, that is 2 non-consecutive fasting days and 5 days of habitual intake per week, and meal replacement diet on glycemic control among patients with early type 2 diabetes compared with metformin and empagliflozin.

According to the International Diabetes Federation in 2021, 537 million adults worldwide have diabetes, affecting roughly 1 in 10 adults.

Overweight and obesity are major risk factors for type 2 diabetes, and appropriate weight loss can improve glycemic control and reduce the need for antidiabetic medications. However, achieving weight loss can be challenging, requiring strategies like meal replacement (MR) or dietary restriction which involves substituting prepackaged food or beverages for one or more meals to provide energy.

The 5:2 intermittent fasting diet, which includes two non-consecutive fasting days (with one-fourth of the usual energy intake) and five days of regular eating per week, has shown promise. Previous studies found that a 12-month 5:2 intermittent fasting diet significantly reduced HbA1c levels in overweight or obese patients with type 2 diabetes, compared to a continuous energy restriction diet.

The EARLY (Exploration of Treatment of Newly Diagnosed Overweight/Obese Type 2 Diabetes Mellitus) study was analyzed which screened 509 eligible patients, with 405 randomly assigned to three groups for an intention-to-treat analysis. Participants were allocated in a 1:1:1 ratio to receive either metformin, empagliflozin, or a 5:2 meal replacement (MR) diet for 16 weeks, followed by an 8-week follow-up. The primary endpoint was the change in hemoglobin A1c (HbA1c) levels from baseline to 16 weeks. Secondary endpoints included changes in body weight, anthropometric measurements, and biochemical parameters.

The result showed that of the 405 randomized participants, 332 completed the 16-week treatment. From baseline to week 16, participants in the 5:2 MR group showed the greatest reduction in HbA1c, significantly greater than patients receiving metformin and empagliflozin. At week 16, the mean weight loss in the 5:2 MR group was greater than that in the metformin group and empagliflozin group.

The findings revealed that, for patients with newly diagnosed type 2 diabetes, a 16-week intervention with 5:2 MR could improve glycemic control and weight loss while also improving blood pressure, triglyceride levels, and HDL-C levels. Therefore, 5:2 MR may serve as an initial lifestyle intervention for patients with type 2 diabetes, providing an alternative to the use of metformin and empagliflozin medications.

Reference: Guo L, Xi Y, Jin W, et al. A 5:2 Intermittent Fasting Meal Replacement Diet and Glycemic Control for Adults With Diabetes: The EARLY Randomized Clinical Trial. JAMA Netw Open. 2024;7(6):e2416786. doi:10.1001/jamanetworkopen.2024.16786