Eat more foods rich in sugar and fat, such as chocolate cake. Eating more high-calorie food will make you fat, and it is best to eat chocolate. Many people eat chocolate and rock candy, and soon they will gain a lot of weight. Drink more high-protein drinks and eat more peanuts, which is very helpful for gaining weight. 1 Eat some high-calorie and high-fat foods: chocolate, cheese, grains, fried chicken, instant noodles, soft drinks, peanuts, beer, animal offal and meat. Eat something sugary (not too much): ice cream, cream, toffee, cake and cake.