Trying to gain muscle mass.

Inb4 "iifym"

Yo, so I've meal prepped 3 weeks worth of chicken breasts and legs (oven baked), steamed broccoli, carrots, string peas, cauliflower, kidney beans and black beans.

I also eat fruits for snacks, plus eggs, tuna, and oats/deez peanutz

No breakfast cereals and no milk.

I also am a certified mcdonalds addict.

I'm trying to gain muscle while maintaining or dropping fat. Sometimes I use mc d to reach caloric goals or even to surpass them.

Is that advisable ?

I see some body builders go on super strict diets, well why can't you eat junk and still have a good physique ?

Does eating one burger kill all your progress made with chicken and lifting weights? I imagine I will get fat over muscle.