Study examines effects of a two-day intermittent calorie restriction diet for patients with type 2 diabetes

Bottom Line: A diet with calorie restriction two days per week was comparable to a diet with daily calorie restriction for glycemic control in patients with type 2 diabetes.

Why The Research Is Interesting: Conventional weight-loss diets with daily calorie restriction are hard to stick with over time. Intermittent calorie restriction diets can be effective for weight loss. This study examined the long-term effects of a two-day intermittent calorie restriction diet with a diet of continuous calorie restriction over 12 months for patients with type 2 diabetes.

What and When: 137 patients with type 2 diabetes were assigned to 1 of 2 diets between April 2015 and September 2017

What (Study Interventions and Outcomes): 70 patients assigned to an intermittent calorie restriction diet (500-600 calories/day) on two nonconsecutive days with their regular diet the other five days per week and 67 patients assigned to a daily calorie restriction diet (1,200-1,500 calories/day) for 12 months (interventions); change in hemoglobin A_1c (primary outcome)

How (Study Design): This was a randomized noninferiority trial. This type of randomized clinical trial is designed to assess whether an intervention is "no worse" than the comparison intervention.

Authors: Peter M. Clifton, M.D., Ph.D., of the University of South Australia, Adelaide, and coauthors

Results: The average change in hemoglobin A_1c after a year was comparable between the two diets.

Study Limitations: The study population had well-controlled type 2 diabetes; medication adjustments can complicate interpreting changes in hemoglobin A_1c levels; and study participants had more contact with a dietitian than is usual in a clinical setting