Both nutrition and physical activity are critical if you want to gain lean muscle.To get started, it’s essential to challenge your body through physical activity. However, without proper nutritional support, your progress will stall.High-protein foods are very important for gaining muscle, but carbohydrates and fats are also necessary sources of energy.If your goal is to gain lean muscle, you should focus on exercising regularly and eating more calories each day from muscle-building foods. ~ Berceste