Foods that help gain weight are; fruits (avocado, apple, oranges, strawberries, lemons, all types of berries, apricots, grapes, etc.), grains (brown rice, whole wheat preparations, sugar-free granola), and vegetables (carrots, broccoli, wheat, cabbage, beans, Brussels sprout, asparagus, radish, beets, spinach, tomatoes, onions, cauliflower, etc).