>>26218714>the large breasts of overweight or obese mothers contain more fat cells than milk-making cellsNote that this specifies large tits caused by being fat, not tits that are naturally big. As always, the wisdom that big tits on a fat girl are meaningless still holds.
The absolute best milk-tank would be a girl who had naturally big tits, which then grow even further during pregnancy, so you're adding milk-making cells on top of milk-making cells, ending with a girl whose huge, ripe breasts overflow with rivers of milk.
