It is not an easy task to stay lean and eat enough clean protein. If you are serious into working out, you probably know what macronutrients are, and how you should care about them to support your body.
Eating clean protein is a hard task, unless you drink protein shakes or separate few egg whites and eat/drink them. There are some other sources of clean protein like some types of meat and fish, but it is a bit more hassle due to the cooking time.
So it is not that easy. But you have to keep doing it. You can’t drop the ball. It is that important. As important as going to the gym.
There will be days that you don’t have something clean to eat and you’re about to give up. So another fantastic exercise for the discipline.