List of energy-dense foods that are perfect for weight gain:
Nuts: Walnuts, almonds, peanuts, macadamia nuts, etc.
Dried fruit: Dates, raisins, prunes.
High-fat dairy: Full-fat yogurt, whole milk, cheese, cream.
Fats and Oils: Avocado oil, extra virgin olive oil.
Grains: Whole grains like brown rice and oats.
Meat: Beef, Chicken, pork, lamb, etc.
Tubers: Sweet potatoes, potatoes, and yams.