>>714872991
Actual, real Gynecomastia is the presence of breast tissue, not just fat (fatties have pseudo Gynecomastia). Around 70% or so of boys has it before/during puberty and about 25% keep it into adulthood. It varies from puffy nipples to full on booba.
So the size varies greatly with the weight loss per person based on the base breast tissue %. So I guess, if you already look very feminine and if your breast are mostly made of breast tissue and don't go away with the weight loss, they can become very apparent. I was constantly mistaken for a budding girl when I was young, my breast where quite puffy and you could see them through the shirt (I also had very long hair on top of being already feminine).
I'm still skinny, but they are less prominent now with a layer of fat and muscle on top. So if you want to lose weight, lift some as well.