THE IMPACT OF KETOGENIC DIET ON MALE REPRODUCTIVE HORMONES: A COMPREHENSIVE REVIEW

Abstract

The ketogenic diet, characterized by very low-carbohydrate and high-fat intake, is widely used for weight management and metabolic improvement. However, it induces metabolic changes that significantly affect the endocrine system, particularly the hypothalamic–pituitary–gonadal (HPG) axis, which regulates male reproductive function. This review integrates evidence on the effects of the ketogenic diet on testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). A literature search (2010–2025) was conducted using PubMed, Scopus, Web of Science, and Google Scholar. Studies on adult males were included, while animal studies and those lacking hormonal data were excluded. Findings indicate context-dependent effects. In overweight or obese men with insulin resistance, short-term ketogenic diets are often associated with increased testosterone levels, largely due to weight loss, improved insulin sensitivity, and reduced inflammation. In contrast, prolonged adherence, significant caloric restriction, or use in lean, physically active men may suppress the HPG axis, leading to hypogonadotropism with reduced LH and testosterone levels. This effect is likely mediated by decreased leptin levels, which signal energy deficiency to the hypothalamus. Diet composition, particularly fat type, may also influence outcomes. Overall, ketogenic diets tend to improve testosterone in overweight individuals but may reduce LH and testosterone in lean individuals or during long-term restriction, highlighting the importance of metabolic status and energy balance.