how many calories do you have to eat to gain a pound?
Well it depends what your total intake of calories is. You need to cut back on 500 calories/d to lose 1 # per week. So do the math. Add 500 calories to your diet.
If you are thinking of gaining dont eat junk food because it will only increase your adiposity (fat). Go to mypyramid.gov example: 300 calories are equivalent to a yogurt and 4 graham crackers.
hmm... this is a tough one... because some people, no matter how much they eat, will simply burn it off... it's about 3500 cals in a pound, but really high metabolism means it probably wont work... if you want to gain weight, try exercise, weights etc, and load up on protein...