The research on excess weight in men and its reach into hormones, fertility, and metabolic health.
This study set out to review how different weight loss methods affect male fertility in men with obesity. It looked at 32 studies that compared lifestyle changes, medications, and bariatric…
This study looked at how a man's testosterone and SHBG relate to where his body stores fat. SHBG, or sex hormone-binding globulin, is a protein that binds testosterone and sets…
This umbrella review (a review of other reviews) set out to catalogue what damages male fertility. It gathered 43 systematic reviews and meta-analyses published between 2000 and 2025, covering 67…
This study looked at how different measures of obesity relate to semen quality in men from infertile couples who had no other known fertility risks. It compared body mass index…
This study compared two exercise approaches, high-intensity functional training (HIFT) and traditional resistance training (RT), for improving metabolic, inflammatory, and physical health in overweight men. Thirty-four men with an average…
This study set out to examine how modifiable lifestyle factors like smoking, drinking, and weight affect semen quality in men. It analyzed data from over 3,300 men visiting a fertility…
This study set out to compare how men and women respond to a 12-week Mediterranean-style weight-loss diet, focusing on changes in body fat, eating habits, and mental health. It followed…
This systematic review set out to assess how GLP-1 receptor agonists (a class of diabetes and weight-loss drugs) affect male reproductive hormones, semen quality, and metabolic health. It pooled data…
This study set out to explore how obesity and chronic inflammation relate to testosterone levels in men. It analyzed data from over 7,400 adult men in the US, using body…
This study set out to see if cutting protein while keeping calories the same could help men with overweight or obesity lose weight. Seventeen men were randomly assigned to eat…
This study built a better way to read testosterone in men, especially men with obesity, by accounting for SHBG (sex hormone-binding globulin, a protein that binds testosterone and sets how…
This study tested whether pairing intermittent fasting with weightlifting improves body composition in obese men. It randomly assigned 20 obese men aged 20 to 30 to either a normal diet…
This is a narrative review (an expert summary of existing research, not a new experiment) asking whether testosterone replacement therapy (TRT) could help men with low testosterone hold onto muscle…
This review looked at how aging affects men's hormones, sleep, and metabolism, centering on two kinds of hypogonadism (when the testicles do not make enough testosterone, causing symptoms like low…
This study looked at whether obesity speeds up the decline in sperm quality that has been seen over time. Researchers reviewed semen tests from 2,430 men with normal sperm counts…
This meta-analysis (a study that statistically pools many earlier studies) looked at how body mass index (BMI, a weight-for-height number used to flag over- or under-weight) relates to sperm quality…
This study looked at how different types of exercise affect body composition during weight loss. It compared resistance training, aerobic exercise, and no exercise in 304 adults on a calorie-restricted…
This review gathers recent evidence on what damages male fertility and how much of it can be undone. Smoking raises sperm DNA fragmentation (breaks in the genetic material inside sperm)…