Okay, one, if you're really that worried about it, either do your own research or talk to one of the doctors in medbay. That's kind of what they're there for.

Two, yes, I do want you to have a healthier diet, but I also learned a long time ago that scaring you into doing things doesn't work in the long run! Eating nothing but cookies all the time will fuck you up; having a cookie every once in a while will not.