Be Cautious on What you Eat when you Travel.
1. Water is very important while traveling as it keeps you hydrated.
Make sure to drink from a dependable source and the seal on your bottled drink is intact. Use bottled water in brushing your teeth. As much as you can, ask for drinks without ice unless you are sure that they're made with purified water.
2. A lot of bacteria and germs won't survive in high heat which is why it is usually safe to eat food that is cooked thoroughly and served steaming hot. Take extra guard if food is served in a buffet where it may have stayed at room temperature for quite a while. Same thing applies in drinking hot drinks, it would be safer if it is served steaming hot as well rather than it being served warm or at room temperature.
3. Eating raw or under-cooked meats and fish including shellfish may be risky and should be avoided as much as possible. In eating fruits and vegetable, keep in mind that you should be the one to wash, cut or peel them.
4. Street vendors in all places of the earth may or may not follow the universal hygiene standards of food safety. I won't be able to tell you to stay away from street food as this is the best way to experience the different culture of the places you visit and would help you in your budget. The best measure to apply here is to choose steaming hot food right after you've seen them finished cooking and be smart.
5. Food that is dry, packaged or factory sealed like bread, potato chips or canned tuna are usually safe since most germs require moisture to thrive. Make sure to check the packaging is not damaged or ripped. Make it a habit to always check the expiration dates of the food that you eat if there are any.
6. Avoid dairy products like cheese, milk or yogurt which are not pasteurized. Always check on the pasteurization date. Be careful on using creams for your coffee or milk you put in your cereal that may have been sitting at room temperature for some time.
7. The most important thing to remember is to wash your hands specially before eating. Do not put your fingers in your mouth. Use alcohol-based sanitizer if soap and water are not available.
But don't get too obsessed with this or it may end up ruining your trip. Just be cautious of what you eat and don't forget to enjoy. If you do get sick, don't panic. Most cases of traveler's diarrhea may clear up after a few days though there could be some instances that may need medical help.