What to eat to gain muscle mass?

See below: The rule of thumb is that you need between 1 and 1.5 times your body weight (if you are overweight, then substitute your target body weight) in grams of complete protein. Complete proteins are eggs, meat, fish, cheese and milk. This will work better than incomplete protein, i.e. Soy or plant based. Include more carbs at breakfast and eat healthy fats. Don't skip meals and drink plenty of water.