My step dad is the shit, but one thing he frowns upon is pot.
My mum doesnt smoke it anymore cause of him and I'm not allowed to smoke it in my room anymore xD Other then that hes the same way as my mother, perhaps even a little more lenient hehe! But I really think it has to do with honesty, I never lie to my parents as I see no need to. Lies only get you into more shit.

edit: what i forgot to say about my step dad is he is one jacked muuh fucka lmao, and he's all into his protien shakes etc though we always got my favorites on hand, pogos taquitos and butter chicken~ I usually do eat a decent amount of crap so I'm glad my mumma cooks healthy dinners every night and makes me take my vitamens hehe.
So yes I may smoke pot and drink but atleast I try to off-set it with exercise and healthy eating! its not as if I'm a lazy fuuck.

Honesty is key. I could do whatever I wanted cause I would usually come home an hour before curfew so when I really wanted to stay out I'd get the thumbs up from my mom.

Just swallowing soy protein and veggies wouldn't really help you. As long as you're not sitting on your bum all day stuffing your face a bit of junk food wouldn't hurt IMO. In fact, if you only eat organic foods or some super healthy thing... I would think it'd make you sick in a different way.

Considering your a kid to .. maybe when your older eating that will really affect you but right now cillia it won't to some extent.