How much fat do you have to eat to gain one pound?

1 pound of fat will make you gain 1 pound. No matter what you eat you gain the wait of what you eat for that moment. You can eat .5 pounds of anything and gain more the .5 pounds. However over a day you can burn more. Other Words you could eat 1 pound of fat and by tommarow only weigh .5 pounds more. It depends on your matablism and exersice/activity