Immediate and long-term effects of a very-low-calorie diet on diabetes remission and glycemic control in obese Thai patients with type 2 diabetes mellitus

Aim: A very-low-calorie diet (VLCD) can reverse the underlying defects of type 2 diabetes mellitus (DM) in obese subjects. We determined the efficacy, safety, and durability of VLCD in Thai patients with DM and obesity.

Methods: Twenty Thai patients with DM and obesity were enrolled. After a 2-week trial, VLCD (600 kcal/day) was continued for 8 weeks, followed by a 4-week transition period. Data on diabetes remission (fasting plasma glucose level <126 mg/dl and HbA_1c <6.5% without the use of glucose-lowering medications), glycemic control, metabolic parameters, and quality of life (QOL) were collected along with indices of insulin resistance (IR) and beta cell function. Glycemic control 12 months after discontinuation of VLCD was also examined.

Results: Among 19 patients (age 48 ± 2 years, BMI 27.7 kg/m²) who completed the study, rapid improvement in glycemic control was observed in the first 2 weeks of VLCD. At both 8 and 12 weeks, diabetes remission was achieved in 79%. Significant weight loss was accompanied by a significant reduction in IR and an increase in beta cell function, starting at 4 weeks of VLCD. QOL also significantly increased. At 12 months after VLCD, however, DM remission was achieved in approximately 30%.

Conclusion: Very-low-calorie diet was effective and safe in inducing short-term diabetes remission in Thai subjects by ameliorating beta cell function and IR. Optimal long-term glycemic control was potentially durable as one-third of subjects remained without diabetes medication 12 months after VLCD.