Energy-Restricted Diet Twice Weekly Tops Exercise in T2D

TOPLINE: 

Two days a week of a medically supervised energy-restricted diet may lower blood glucose levels in adults with overweight or obesity and type 2 diabetes (T2D).

METHODOLOGY:

• Daily calorie restrictions and increased physical activity improve glycemic control and induce diabetes remission in patients with T2D, but these approaches are challenging to adhere to.
• Researchers tested whether 2 days a week (a 5:2 regimen) of either a very low-calorie formula diet or a "weekend warrior" physical activity pattern would be effective and more convenient.
• The three-arm IDEATE study enrolled 326 Asian participants with overweight or mild obesity (body mass index, 25.0-39.9) and T2D (diagnosed within prior 2 years; A1c, 7.0-8.9%; not on insulin) and randomly assigned them to receive a diet intervention, an exercise intervention, or routine lifestyle education (control group) for 12 weeks.
• The diet intervention group received an energy-restricted diet of 790 kcal/d on 2 days each week, and the exercise intervention group performed high-intensity interval training (4 minutes of aerobic activity, with a 10-minute total warm-up and cool-down) and resistance training twice a week (four exercises, two sets of eight to 12 repetitions).
• The primary outcome was the change in glycemic control between the diet or exercise intervention group and the control group after 12 weeks. Follow-up continued up to 1 year after intervention.

TAKEAWAY:

• Compared with the control group, patients in the diet intervention group achieved greater reductions in A1c after 12 weeks (difference, -0.34; P =.007), whereas A1c reductions in the exercise intervention group did not differ significantly from the control group.
• The likelihood of achieving diabetes remission was higher in the diet intervention vs the control group (adjusted odds ratio, 3.60; P = .008) but not in the exercise intervention group (P =.52).
• Body weight, body mass index, and high-density lipoprotein cholesterol levels were more effectively controlled in the diet intervention group only.
• However, participants in both the diet and exercise intervention groups showed reduced adiposity, liver fat content, and diastolic blood pressure compared with those in the control group.

IN PRACTICE:

"The diet intervention group experienced a greater energy deficit with a more pronounced metabolic benefit," the authors wrote. "Our study suggests that a medically supervised 5:2 energy-restricted diet could serve as an alternative strategy for improving glycemic control." 

SOURCE:

Mian Li, of the Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, led the study, which was published online in Diabetes Care.

LIMITATIONS:

Body composition was analyzed using bioelectrical impedance analysis, which is a less accurate technique than dual-energy x-ray absorptiometry. The study used finger-prick tests to monitor blood glucose levels, which could have underestimated both hyperglycemic and hypoglycemic episodes. No information was collected on whether the participants maintained the diet or exercise regimen during the postintervention follow-up period.

DISCLOSURES:

This study was supported by the National Key Research and Development Program of China, National Natural Science Foundation of China, Shanghai Rising Star Program grant, and other sources. The authors declared no conflicts of interest.