Case report: sustained weight loss and glycemic control from repeated long-term fasting in type 2 diabetes

Marie Knufinke¹Marco Lebbing¹Robin Mesnage^2*

• ¹Buchinger Wilhelmi clinic, Überlingen, Germany
• ²King's College London, London, United Kingdom

Type 2 diabetes mellitus (T2DM) is a common metabolic disorder typically managed with medication; however, fasting has recently attracted attention for its potential benefits in glycemic control, weight management, and even potential remission. This case report examines the effects of repeated long-term fasting on weight reduction, glycemic control, and medication requirements in a 57-year-old man with T2DM. The patient, who had a history of inadequate glycemic control despite conventional treatment, opted for repeated long-term fasting under medical supervision. He completed several fasts ranging from 11 to 20 days each, with each fasting period followed by a gradual reintroduction of food via a hypocaloric lactovegetarian diet (800–1,800 kcal) over 4 to 16 days. The intervention resulted in sustained weight loss and improved blood sugar control. Notably, clinically meaningful improvements occurred in fasting blood glucose levels, which necessitated adjustments in his antidiabetic medications. Enhanced insulin sensitivity was evidenced by decreased HbA1c levels and a reduced dependence on hypoglycemic agents. Additionally, post-fasting evaluations indicated improvements in inflammatory markers and a reduction in fatty liver disease. In summary, repeated long-term fasting in this patient was associated with sustained weight loss, improved glycemic control, and reduced medication requirements, thereby enhancing the overall management of T2DM. Further research, including randomized controlled trials, is needed to better understand the long-term safety and effectiveness of this intervention.