Dietary Interventions and Testosterone Levels in Obese Men: A Systematic Review Comparing the Mediterranean Diet,...

Male obesity secondary hypogonadism (MOSH) is a highly prevalent condition characterised by reduced testosterone levels in obese men, driven by increased aromatase activity, reduced SHBG, insulin resistance, and HPG axis suppression. Dietary interventions represent a cornerstone of non-pharmacological management; however, the comparative efficacy of different dietary patterns on testosterone restoration remains unclear.

We conducted a systematic literature review following PRISMA 2020 guidelines. Comprehensive searches were performed in SciSpace, Google Scholar, and PubMed through June 2026. Eligible studies included human adult males with obesity (BMI ≥ 30 kg/m²) undergoing Mediterranean diet (MedDiet), ketogenic diet (KD/VLCKD), or intermittent fasting (IF) interventions, with quantitative assessment of testosterone or androgen status.

From 697 initial records, 500 unique papers were identified after deduplication. Following abstract screening (n = 442 excluded) and full-text assessment (n = 6 excluded), 52 studies were included in the final synthesis. VLCKD demonstrated the most consistent evidence for testosterone improvement, with RCTs reporting significant increases in total testosterone (+1.5 to +3.0 nmol/L). Intermittent fasting showed promising but more heterogeneous results. Evidence for Mediterranean diet was limited, focusing primarily on metabolic rather than hormonal outcomes. Weight loss emerged as a critical mediator across all dietary interventions (~3 nmol/L per 10 kg weight loss).

Among dietary interventions for MOSH, VLCKD shows the strongest evidence for testosterone restoration in obese men, through rapid weight loss, improved insulin sensitivity, reduced inflammation, and potential direct HPG axis effects. Intermittent fasting represents a viable alternative. Mediterranean diet, while beneficial for cardiovascular health, lacks robust interventional evidence for testosterone improvement in this population.

This review was not prospectively registered. PROSPERO registration is recommended for future updates.