Bariatric surgery is an effective method in the treatment of severe obesity and type 2
diabetes mellitus achieving high remission rates. However, weight loss also causes loss of
skeletal muscle and bone mass which at least partly could be prevented by exercise and
dietary intervention although the counselling of obese and sedentary individuals in order to
increase their physical activity presents a challenge. As up to 78.8% of men undergoing
bariatric surgery have low levels of testosterone, testosterone therapy could be considered
an attractive alternative or supplement to prevent the immense loss of muscle mass during
weight loss. Furthermore, low testosterone levels are associated with sarcopenia, insulin
resistance, increased body fat, reduced quality of life, loss of libido and reduced sexual
function. The study is a long-term randomized, placebo-controlled trial investigating the
effects of testosterone therapy combined with exercise and diet counselling on body
composition, components of the metabolic syndrome, hormones, inflammation, sexual function
and quality of life before and after weight loss in obese, hypogonadal men undergoing
bariatric surgery.