Here are some tips to avoid food poisoning on your next trip abroad:
Keep your portions small so you don't shock your digestive system. (This is particularly hard for me to do when in Poland or France).
Try to pay attention to how the food is prepared. I would definitely go to a cafe and eat something that has to be cooked instead of an already pre-packaged meal sitting in the refrigerated section.
Avoid buying ice cream from unknown vendors. You don't know if it's been properly refrigerated and if it isn't then that gives bacteria a chance to grow.
For people who are seafood lovers, myself included, it is best to avoid anything raw. As much as I like fish, I have a minimal amount (if any) when in another country. Undercooked seafood is at the top of the list for how people get food poisoning.
Pay attention to what you are drinking and make sure to have a bottle of water with you to stay hydrated so you don't find yourself drinking the local water. But make sure the bottle is sealed as some restaurants are known to refill bottled water with local water. When I'm with my family in Poland they boil a bunch of water for me and it lasts all day. If you want to eat fruits or vegetables make sure you rinse them with your bottled water because either they haven't been rinsed or they've been rinsed with local water.
With that said, you should DEFINITELY avoid ice- ALWAYS. You just get use to drinking soda without ice, well sort of, but at least you don't get sick.
The BEST way to avoid getting sick is actually leading a healthy lifestyle as much as possible. If you don't practice a good lifestyle now there is still room to change that before a trip. Try to exercise as much as possible, get lots of sleep, and eat plenty of fruits and veggies. I know that when I've been taking care of myself in the past and have taken three trips to Europe in the span of 4 months I didn't get sick once. And most of my time on the plane exceeded 20 hours.
Another thing I like to do is have the local yogurt as it coats your stomach with bacterial cultures that aid digestion and fight the so called bad bacteria. I usually do this the first day and then off and on throughout my trip.
While I am at the airport I put a Vitamin C packet in my water and when I board the plane I wipe down the arm rests, tray table, seat-belt, window with wet-wipes.
And yes I ask the person next to me to move their arm if they are already seated..they usually appreciate it.
I hope this helps some of you on your next trip!