I meant to post this a while ago. I eat pretty dam healthy, and about a month or so ago, i ate a hot dog (frankfurt type red one) from a vendor because there waas nothing else and i was starvning, and it made my stomach feeel soo soo sick, i felt like dying
maybe just indigestion? Hot dogs aren't exactly the best things for ya and who knows how they were prepared(especially from a street vendor or something). If you eat very lean and clean, it could have just caught your stomach a little off-guard.
Any sudden changes to your diet could cause a number of responses(indigestion, could have been food poisoning, rare/uncooked/spoiled meat). I'm trying to stop all red meat or pop of any kind and just do chicken/fish/water/milk and it's extremely hard to manage due to my metabolism. I almost need those extra calories and caffeine to function haha.
You probably just weren't used to it. I remember my friend gave up pop for an entire year and then one day he decided to have a pepsi. It made him feel like sh*t. It might be the same effect happening to you.