Negar Yavari - Department of medical physiology, Faculty of medicine, Isfahan University of medical sciences, Isfahan, Iran.

Introduction: One of the most common health issues worldwide is obesity. Fertility can be negatively affected by obesity. In men, obesity is associated with low testosterone levels they are having a higher risk of impaired spermatogenesis, reduced circulating testosterone levels, and erectile dysfunction. The diagnosis and treatment of underlying causes of infertility such as obesity require clear insight into the underlying mechanism, which has physiological, hormonal, and mechanical aspects. This review summarized the current experimental and clinical evidence, and recent diagnostic approaches to obesity in adult men and different types of diets aimed to improve reproductive health in males.Methods: We conduct a comprehensive search in PubMed, Up-to-date, and Cochrane databases. Nineteen studies on obesity and male infertility were systematically reviewed, including case-control studies and randomized controlled trials.Conclusion: Evidence exists demonstrating the strong relationship between obesity, diet, and male infertility. Considering the new information, this effect consists of multiple factors and several different pathophysiological mechanisms for instance in some studies obesity was contributed to a decrease in sperm concentration and motility in comparison with normal men. Numerous studies suggested that obesity and several kinds of diets were strongly associated with infertility in men and women. Erectile dysfunction seems to diminish in men adhering to the Mediterranean diet. Weight loss in obese men through low-fat, low-calorie diets seem to have enhancements in their erectile function and testosterone levels. Moreover, a Western diet is accompanying with lower semen quality. However, the lack of randomized studies evaluating barriers to infertile obese men is obvious, and future research should examine these issues further.

Obesity, Infertility, Diet, Systematic review