gain wt? lift weights
lose wt? lift weights
female? calcium. LOTS OF IT
can you deadlift a baby? bench a baby? outrun a child? carry a child? squat a child? bench a child? no? there's a fitness goal for you.

my friend can do 50 body mass squat reps and bench 40 lbs. I'm like O_o joanne can't even do 20 lbs to which said friend pointed out that babies grow up fast.

on topic if you eat nutritionally empty foods you will be incapable of many fun things that are good for you. the specifics of how much you eat is irrelevent - you cannot overeat on a clean diet