Not all tap water is safe to drink.

Using discretion and common sense, Eat and drink whatever you like when you are on the road. Follow these basic guidelines, and you will never suffer from Tehran Tummy or Delhi Belly.

Take precautions on the flight. Long flights are dehydrating.  Eat lightly, stay hydrated, and have no coffee or alcohol and only minimal sugar until the flight’s almost over. Avoid the slight chance of getting a blood clot in your leg during long flights by taking short walks hourly. While seated, flex your ankles and don’t cross your legs. Some people are more prone to clots (factors include obesity, age, genetics, smoking, and use of oral contraceptives or hormone replacement therapy).

Eat nutritiously. The longer your trip, the more you’ll be affected by an inadequate diet. Budget travelers often eat more carbohydrates and less protein to stretch their travel dollars. This is the root of many health problems. Protein helps you resist infection and rebuilds muscles. Get the most nutritional mileage from your protein by eating it with the day’s largest meal (in the presence of all those essential amino acids). Supplemental super-vitamins, taken regularly, help to at least feel healthy.

Use good judgment when eating out. Avoid unhealthy-looking restaurants. Meat should be well cooked (unless, of course, you’re eating sushi, carpaccio, etc.) and, in some places, avoided altogether. Have “well done” written on a piece of paper in the pertinent language and use it when ordering. Pre-prepared foods gather germs (a common cause of diarrhea). Be especially cautious. When in serious doubt, eat only thick-skinned fruit…peeled.

Exercise. Physically, travel is great living — healthy food, lots of activity, fresh air, and all those stairs! If you’re a couch potato, try to get in shape before your trip by taking long walks. People who regularly work out have plenty of options for keeping in shape while traveling. Biking is a great way to burn some calories — and get intimate with a destination. Though running is not as widespread it’s not considered weird either. Traveling runners can enjoy from a special perspective — at dawn. Swimmers will find that they are plenty of good, inexpensive public swimming pools. Whatever your racket, if you want to badly enough, you’ll find ways to keep in practice as you travel. Most big-city private tennis and swim clubs welcome foreign guests for a small fee, which is a good way to make friends as well as stay fit.

Get enough sleep. Know how much sleep you need to stay healthy (generally 7–8 hours per night).

Colds: It’s tempting to go, go, go while you’re there — but if you push yourself to the point of getting sick, you’ve accomplished nothing. Keep yourself healthy and hygienic. If you’re feeling run-down, check into a good hotel, sleep well, and force fluids. Stock each place you stay with boxes of juice upon arrival. 

Constipation  from  all the bread you’ll be eating.  Get exercise, eat lots of roughage (raw fruits, leafy vegetables, prunes, or bran tablets from home), and everything will come out all right in the end.

Get vaccinated.

Because falling prey to an illness in a foreign country is not fun — and many countries require you to get vaccinated in order to visit them so, regardless of your opinion on the subject, you just might have to.

Have a health checkup before you leave

Visit your doctor and dentist for a checkup before you leave. The last thing you want to happen is for you to set off and discover two weeks later that you need to get a filling in the middle of no-where.