Very low-calorie diet in patients with longstanding type 2 diabetes mellitus: a study of real-world outcomes

Introduction: There is a paucity of evidence regarding the efficacy of a very low-calorie diet (VLCD) in the real-world setting. We evaluated outcomes in patients with type 2 diabetes mellitus (T2DM) who underwent VLCD. Methods: This retrospective observational study included all patients who had undergone VLCD from 2014 to 2017 (n=61). The VLCD consisted of an eight-week 800 kcal/day dietary restriction. Metabolic parameters and medications were recorded at baseline, immediately post-VLCD and at 6 and 12 months. Results: There was a significant reduction in weight of 9.96 kg (p<0.001) immediately post-VLCD, with net weight loss sustained to 12 months (p<0.05). There was a significant reduction in body mass index (BMI) sustained to 12 months (p<0.05). Paired HbA1c data were available for 38 patients. There was a significant reduction in HbA1c of 13.29 mmol/mol immediately post-VLCD (p<0.001), however no significant reduction was observed at 12 months (p>0.05). 78.7% patients had a reduction in T2DM medication burden post-VLCD, sustained in 44.3% of patients at 12 months. Analysis of patients with T2DM diagnosis duration >6 years demonstrated statistically significant weight loss sustained to 12 months (p<0.001). Conclusion: Our results demonstrate sustained reduction in BMI and weight, reduction in medication burden and temporary reduction in HbA1c in patients with T2DM undertaking a VLCD in the real-world setting