How does your body react to unhealthy food?

I get food hang overs. Last night I ate cookies and a rue sauce for dinner... Needless to say I am paying for it today. I literally feel sick as if I have the flu. Today, it's been hot tea, chicken soup (very healthily made), bananas, and sweet potatoes- all because I gave in to a few sweet treats the night prior. When we eat healthy, our body becomes very sensitive to food (i.e. very sensitive to processed foods). I can't even drink alcohol without feeling overly sick (something that has become acquired.) I find it a gift being this sensitive - our body has gotten used to the "finer" things in life - eating healthy is a privilege. Next time you get the bug to eat sweets, try turning fruit into your next desert. Baked or seared fruit is divine!