Actually, I think there might be some truth to this, but it depends on the individual and genetics. I personally find that after a couple days of smoking massive amounts of dank bud that my veins don't show as much and my muscles don't seem as tight and hard. However, If I'm somewhere like a concert where I'm really physically active, dancing and smoking massive amounts of good bud, I don't notice this change in physique at all. So it could perhaps be more related to the laziness, but If I'm sitting around all day doing nothing and not smoking, I do not notice this change. As far as growing breasts though... shit you'd probably have to smoke ounces a day of fire ass weed and be a fat ass slob.