Eating when you are not hungry is the best ways to gain weight. Whenever you start to eat, you make yourself hungry. Eating stimulates insulin and other hormones are released, that stimulate your appetite. If you are not hungry, don’t eat. Always go as long as you can without putting anything in your mouth. Liquid calories are the second best way to pile on weight. Juice, sugared soft drinks and ice cream and cheese (I consider both ice cream and cheese liquid calories) are caloric nightmares – way too many calories, way too fast, that do not create satiety.