All I can say is WHY 
Girls and sons who have not been loved by their fathers seek attention once teens and adults to compensate for what they didn't have originally. Fathers either left them alone, or were distant most of the time and not encouraging them.
Some even despised them which would shape their personality and the way they they interact with others for the rest of their life.
They are extremistic in everything they do, always looking exaggeratly for attention (Hello Goodrum), and have troubles adapting to society's rules, because they also have troubles defining their own identity and respecting authority and hierarchy.
Also boys who got picked on by others during childhood and adolescence -often sons without a father figure- try to compensate by lifting weights, to develop muscles and survive in ther male world.
They're insecure because they're girly, childish, feminine having been raised by a single mom.
They lift obsessively hoping it will transform them into men, to compensate for their lack of influence from a father figure that was not there. Unfortunaltey they can get as big as they can it doesnt cure their insecurity and who they truly are, how they grew up being raised by a single mom. They re no as manly as other men whatever they do, and they often have a big lack of masculine presence they dont know how to balance, hence often being borderline homosexuals while trying to get their manhood back thru various manly activities (mma, cars, weight lifting etc).
They are often the ones that, in order to get respect from other males will go the steroids route to get even "bigger" attemptint to cure their insecurity , but being natural not being "enough", they still feel "too small", insecure, amongst other males. The lack of a father figure also often means they didnt have guidance to continue studies and are often working shitty manual jobs.
