The effect of fasting Ramadan on type 2 diabetes: A narrative review and practice update.

Abstract

Ramadan fasting, observed by Muslims worldwide for over 1,400 years, involves abstaining from food, drink, and other physical needs from dawn to sunset. Despite exemptions for individuals with chronic conditions, many patients with type 2 diabetes mellitus (T2DM) choose to fast, raising concerns regarding safety and metabolic control. To synthesize recent literature (2021-2024) on the physiological impact of Ramadan fasting on individuals with T2DM and offer evidence-based recommendations for safe fasting practices. This narrative review evaluates recent clinical studies on the effects of Ramadan fasting in T2DM patients. Key areas include metabolic outcomes, potential risks, and strategies for pre-Ramadan assessment and individualized care. Emerging evidence suggests that Ramadan fasting may offer metabolic benefits to T2DM patients, including improved insulin sensitivity, reductions in body weight, fat mass, blood pressure, and proinflammatory cytokines. Positive changes in gut microbiota and hormonal regulation have also been reported. However, without proper medical oversight, fasting may increase the risk of hypoglycemia, hyperglycemia, dehydration, and diabetic ketoacidosis. The physiological mechanisms of Ramadan fasting align with those of nonreligious intermittent fasting, which also show favorable outcomes in glucose and lipid regulation. Ramadan fasting can be safe and beneficial for many with T2DM when properly managed. Pre-Ramadan planning-including risk assessment, medication adjustments, and education-should begin 6-8 weeks in advance to reduce risks and guide informed decisions.