When it comes to building muscle, does diet play a role? Absolutely. For the first couple years I worked out I failed to change my diet, and while I saw some definition I didn’t really start bulking up until I learned how to tweak my diet.
So much of gaining or losing weight is a numbers game with calories. Your body burns a certain amount of calories a day, so in order to lose weight you need to be in a calorie deficit, where you consume less calories than you burn.
On the other hand it’s no different when you are building muscle, you need to eat more than you are burning in a day. If your body is not getting enough calories, you can lift weights all day and you will grow your muscles, because there is simply nothing there for your muscles to build with, no building blocks if you will.
Your body needs whole grain foods, and protein to help restore the torn muscle fibers that come from a good hard workout.