THURSDAY, Nov. 13, 2025 (HealthDay News) -- Lifestyle changes are associated with modest improvements in sperm motility and morphology among men with obesity, according to a review published online Oct. 9 in Human Reproduction Update.Andrew Peel, from the University of Adelaide in Australia, and colleagues conducted a systematic literature review to examine the reproductive effects of obesity interventions in men with obesity.Based on 32 included studies, the researchers reported that a fixed- and random-effects meta-analysis of randomized controlled trials identified no differences in sperm parameters between control and intervention arms across any intervention; the trials were limited in interpretability by small sample size. Similarly, for bariatric surgery, random-effects meta-analyses of pre-post outcomes identified no clinically significant semen parameters or DNA damage changes. Five studies of pharmacotherapy (metformin and liraglutide) had insufficient data to draw clear conclusions regarding the impact of these agents on fertility outcomes. Ten studies evaluated lifestyle interventions, and in those, a fixed-effect meta-analysis identified improvements in sperm normal morphology (mean difference, 0.59 percent) and progressive motility (10.56 percent) following a lifestyle intervention."This indicates that for men with obesity, whilst obesity has detrimental effects, reproductive success may be more dependent on optimizing nutrition and exercise rather than substantial weight loss alone," Peel said in a statement.Abstract/Full Text.Sign up for our weekly HealthDay newsletter