When doing muscle-building, do not work the same muscle group two days in a row. As for
diet try eating small meals, every 3-5 hours, It helps keep your blood sugar levels more steady. Long periods without eating can cause your body to store fat because your metabolism slows down and your body enters the starvation state. Eat at least 5 times per day.
Keep you carbohydrate to protein ratio at 2:1, which will be one serving of carbohydrates for every small serving of protein.