Sexual Dimorphism and Menopausal Transition: A Narrative Review of the Metabolic and Physical Effects of Intermittent Fasting

The global rise in obesity and cardiometabolic disease represents a major public health concern and contributes significantly to cardiovascular morbidity and mortality. Contemporary Western dietary patterns and excess adiposity are strongly associated with atherosclerotic cardiovascular disease. Although pharmacologic therapies have expanded, lifestyle interventions remain the cornerstone of prevention and management. However, identifying sustainable and effective dietary approaches continues to be challenging given the wide range of available nutrition regimens. Intermittent fasting (IF) has emerged as a promising strategy for weight reduction and metabolic improvement. In this article, we review the physiological effects of IF, including metabolic switching, ketosis, and improvements in insulin sensitivity and inflammatory regulation. We also evaluate clinical evidence regarding the impact on cardiovascular risk, as well as its safety and tolerability. We examine the hormonal responses to IF based on sex. While early studies raised concerns regarding potential reproductive and endocrine disturbances, recent data suggest beneficial effects in both males and females. IF may modestly reduce testosterone in men without impairing muscle mass or strength and may improve metabolic and reproductive outcomes in women, particularly those with hyperandrogenic conditions such as polycystic ovarian syndrome, with favorable effects also observed in postmenopausal women, especially when combined with physical activity.