how many calories do you need to gain a pound
One pound of fat is equal to about 3500 calories. That means that if you eat an extra 350 calories of food a day, which is about equal to a large piece of cake or a medium milkshake, you would gain an extra pound about every 10 days (350x10). Or you would gain a pound in about 20 days if you eat or drank an extra 175 calories a day (175x20).