According to WebMD, people who want to gain muscle need to consume low-fat protein plus carbohydrates, especially before and after a heavy workout. The protein can come in assorted forms, including shakes, bars, peanut butter, chicken and beans. Lean, healthful protein is ideal as opposed to protein from fried foods. People also need to eat plenty of vegetables and fruits.
For the best possible nutrition while building muscle, WebMD suggests a diet that is about one-third lean protein, such as red meat, turkey and chicken; one-third healthy carbs, such as whole grain breads, rice and pasta; and one-third vegetables and fruits. Eating carbs with protein supplies sugar to boost protein absorption while also supplying fuel for exercise sessions.
WebMD notes that a supplement can help but is not a substitute for real food. Ideally, most of a person's nutrition comes from food he consumes.
Men's Fitness lists eggs as a good food for people who want to build muscle. Eggs work well because they are effective in stimulating muscles to build. Nuts are also a good choice, and they are especially good for people on the go. Protein shakes, cottage cheese, chickpeas, lentils and salmon are other good options for building muscles.