Improved Glycemic Control with a Very Low-Calorie Diet in a Vegan Patient Refusing Insulin: A Case Report

Type 2 diabetes treatment by using dietary intervention is a well-established matter, yet Very Low-Calorie Diet methods for patients who refuse insulin remain understudied. This case study demonstrates successful management using a (VLCD) very low-calorie diet in a patient with severe insulin refusal due to thanatophobia. A 63-year-old vegan male with poorly controlled diabetes (HbA1c=8.2%) declined insulin therapy because of death anxiety. He followed a five-week regimen that combined a low-calorie intake of Nestlé Optifast (600 kcal/day) with an additional 200 kcal/day of non-starchy vegetables while continuing his regular dose of metformin. The results were impressive: He lost 13 kg, which accounted for 13.2% of his body weight. His fasting glucose levels dropped significantly, from 230 to 125 mg/dL, while his HbA1c level lowered to 6.4%. Additionally, his C-peptide levels rose from 0.9 to 1.7 ng/mL, indicating that his pancreatic β-cell function had started to recover. Insulin resistance markers and hepatic steatosis were normalized, while inflammation decreased by half (hs-CRP 6.0 to 2.1 mg/L). Such findings suggest that structured VLCD diet can effectively improve glycemic control in individuals with insulin-resistant diabetes, while circumventing psychological barriers (such as thanatophobia) to insulin therapy. The considerable weight loss likely reduced the ectopic fat deposition by improving metabolic function without hypoglycemia risk, which is a potential factor for patients with thanatophobia. The Very Low-Calorie Diet anti-inflammatory effects may offer further metabolic improvements. This case study supports the role of dietary intervention as a potential alternative for individuals with insulin-resistant diabetes, warranting expanded research in larger populations.