'Man-boobs' can be caused by a hormone imbalance between testosterone and estrogen.
Gynecomastia is the development of large mammary glands in human males, which results in breast enlargement. Aka: man boobs. The condition may occur in infants (who have received female hormones from their mothers) or at any time from adolescence onwards.
It usually occurs when testosterone levels drop, but estrogen levels remain the same. This happens when the body is not given proper nutrition, ages, etc. Like with females’ breasts, males’ breasts can be asymmetrical. When these breasts cause extreme distress, breast reduction surgery is recommended. However, in cases where gynecomastia is caused by poor nutrition, testosterone levels can be brought up to normal levels by improving one’s diet.