yes. eating alot AFTER smoking will decrease your high. i do eat a little bit when im high thought just because everything seems to be so much better. usually i eat dinner or whetever else before i smoke so i dont eat a bunch afterwards. i cant help to not drink something i hate having cottonmouth so i dont care if that decreases my high ill just smoke some more.
i seriously doubt it has a significant and consistant effect either way... even if it made you SLIGHTLY less high, which i severely doubt, it would be worth it, cause nothing beats pigging out on some damn good food every once in a while when you got the munchies
The stoners I associate with always say to never eat after you smoke 'cause it takes away your high.. In my experience I believe that it does take away from your high a little, but not completely... I guess this question is just relative to the person.
I don't think its a scientific "fact" that eating takes away from the high, though that has been my experience. For me, though, the enjoyment from munchie foods makes the mild "down" that follows worthwhile (and i'm sill high afterwards, so it's all good).
I don't think it would have much effect at the beginning of the high. However, during the comedown, your brain is very much depleted of energy, causing that sluggish, "stoned" feeling (as opposed to being "high" - normally, I use those terms interchangeably, but they work well to illustrate this point). When you eat, your brain gets a rush of energy and you feel less stoned. Coffee will also decrease your high in my experience, sometimes quite a bit, for the same reason (it decreases the sluggish, "stoned" effect).