How come women have more fatty breast tissue if men can produce milk too?

Lactation tissue. Lactational tissue is responsible for milk production, not the amount of fatty tissue. Hormonal stimulation to this tissue results in milk.

Related Questions

Why do women have more fatty breast tissue if men can also produce milk?

Genetics. An XX chromosome female is designed to undergo puberty with significant breast development. Males (XY) can develop fatty breasts through gynecomastia or excessive weight gain. There are also several genetic conditions that are called mosaicism that can give a "male" breasts that can produce milk if not surgically interrupted before puberty, however those conditions would look like a female. Read more...