This study aims to compare the efficacy of a partial meal replacement diet with a conventional diet, for inducing weight loss, and improving metabolic and inflammatory profile, endothelial function, erectile function, sexual desire, lower urinary tract symptoms (LUTS), and quality of life in obese men. Men aged 30-65 years, with body mass index (BMI) ≥ 27.5 kg/m2, will be recruited from the community in Singapore. The study will be conducted at Changi General Hospital by trained medical investigators, dieticians and sports trainers. At baseline and 12 weeks, fasting glucose and lipids, insulin, testosterone, sex-hormone binding globulin, serum C-reactive protein and interleukin-6 are measured, endothelial function is measured by the non-invasive EndoPAT method, and validated questionnaires administered to assess changes in erectile function, sexual desire, LUTS and quality of life
