When traveling abroad westerners have to be careful about what they eat as their delicate constitutions are used to a sterilized diet of well cooked/prepared foods. There are abundant food safety regulations in America and in other western countries that are actually enforced so Americans are used to being able to trust their food. That is not always the case overseas.
If someone gets sick its usually from the salad or vegetables. Salads would usually be the safe commendable healthy choice in the US, but abroad they are often a cause of intestinal distress because they may not be cleaned well or may have been washed in dirty water. I know a local neighborhood where a lot of salad and vegetables are produced near the banks of the river but they get their water for the plants from the same muddy water that the neighborhood kids use as a toilet.
Health experts (and experienced expats) recommend soaking your vegetables in a strong bleach solution for at least 30 minutes. Unless you are going to high end restaurants where they can take the time to soak the vegetables its not worth eating your veggies.
Be careful of fast food or convenience food items. A good friend of mine tells the story of when she was flying from Addis to Dakar and during a layover she was hungry and wanted a quick snack. So she grabbed a warm yogurt container from a cooler that had its lights off. At the time she thought the lights were off in the cooler because the light bulb had burned out, not because the cooler was not powered. She said the yogurt tasted ok but a little off, but since she was hungry she ate the whole thing. The next part of her flight was terrible and she could not stray far from the toilet for days.
In reviewing her warm airport yogurt decision she realized she made a couple mistakes. You can’t always trust dairy products as the milk may not have been pasteurized and the yogurt she bought had a label that was mostly written in a language she could not understand. Many of these convenience items may have been prepared well in advance and been sitting around in the heat or open for hours or days. She also said she should have been alarmed when she felt that the container was warm and the flavor was off. However, temperature may not always be an indicator as the item may have spent the day in the heat and only recently been cooled. Of course, the broken cooler was another indicator that she should have made a difference choice.
Its generally a good idea to avoid street food if you are not accustomed to the particular items. For me, its an acceptable risk if you have an idea of what you are eating, its fresh, and the item is cooked completely through in front of you. For example, I love deep fried meat pastries straight from the boiling oil. Pieces of meat on a stick straight off the fire and cooked completely have a good chance of not making you sick. Also look at how the food is handled as fresh hot cooked food dropped in the dirt or handled directly with filthy hands can get you sick too.
One day when a good friend and I were traveling through the grassy hills above Lake Malawi a bunch of kids ran up to our vehicle and tried to sell us some food that they had just caught and cooked. What they were selling could be described as “mouse ka-bobs” as they had eight to ten mice stuck between slender twisted branches that they smoked over small fires by the side of the road. The mice looked plump but they smelled like they hadn’t been completely cooked through so we decided to find something else to eat.
Anybody that has traveled in Africa, South America, or Asia can share similar stories. Its kinda funny to hear the new guy complain that he shouldn’t have eaten the street-side camel on his first day in N’Djamena (was also his first day in Africa). Some take longer to learn than others, like my friend that got E. Coli his first week in N’Djamena from partially cooked meat, massive gastric distress the following week from eating shrimp in a local restaurant (never eat seafood far from the sea), then a couple weeks later got giardia and amoebic dysentery from poorly packaged locally produced cheese and dried meats.