The safety and efficacy of a low-energy diet to induce weight loss, improve metabolic health, and induce diabetes remission in insulin-treated obese men with type 2 diabetes: a pilot RCT

Background: Data are sparse on the safety and efficacy of commercially available energy-restricted meal plans in obese subjects with type 2 diabetes mellitus (T2DM). This study examined the safety and efficacy of a commercially available low-energy diet in insulin-treated obese men with type 2 diabetes. Methods: Eighteen men ≥ 35 years old who had class III obesity, had received insulin treatment for ≥ 1 year for type 2 diabetes, and had glycated hemoglobin (Hb) ≥ 6.5% were randomized to receive either a low-energy diet (N = 9) or standard medical nutrition intervention (N = 9) for 6 months. Results: Compared with 1.5% (± 3.55) in the control group, the mean percentage weight loss in the intervention group at 6 months was 9.6% (±4.91) (p < 0.01). Complete and partial diabetes remission occurred in one subject each in the intervention group and no subjects in the control group. Mean glycated Hb levels were 8.9% (± 2.76) and 9.1% (± 1.53) (p = NS) at baseline and 6.5% (± 0.64) and 7.4% (± 1.12) (p = 0.0606) at 6 months for the intervention and control groups, respectively. Compared with 0.85 mmol/L at baseline, the mean high-density lipoprotein cholesterol (HDL-C) level in the intervention group at 6 months increased to 0.96 mmol/L (p < 0.01) while it remained unchanged in the control group. Conclusions: Among obese men with insulin-treated type 2 diabetes, compared with standard medical nutrition, 6 months of a low-energy diet resulted in complete diabetes remission in one subject and partial remission in another while improving diabetes control and decreasing the median daily dose of insulin in the remainder.