Staying healthy while traveling is easier than you'd think! All you need to do is be prepared. Before you jet out, consider the temporary changes you will need to make and plan accordingly.
Sleep! Your body will already be confused with the time change, so getting quality sleep is key. Make an effort to sleep at least 6 hours per night while traveling. I understand it may be difficult with plentiful sightseeing during the day and experiencing the nightlife in the evening, but if you don't, you are almost guaranteed to catch a cold.
Hydration! It's easy to get dehydrated while traveling, especially when you're on a long-haul flight or busy being a tourist all day. The act of flying dehydrates you as is, so be sure to drink water often to reduce and avoid symptoms, such as headaches and irritability. Avoid drinking pop and alcohol, specifically on the day of travel. As for the rest of the trip, indulging in the country's native brew is encouraged as long as you supplement with water.
Stay active! Skip out on taking an Uber to your next stop and walk it out. Enjoy the scenery and have a peaceful nature walk. If your stay is too far to walk anywhere, try for a hotel workout. Depending on where you are traveling, you may have the opportunity to take an excursion, which is usually more fun than your average hotel workout anyway. These may include bike tours, snorkeling, kayaking, etc.
Be aware of new cuisine! If you plan on eating foods you haven't tried before, your gut may have a little shock. In order to avoid an upset stomach, take some pepto bismol or similar to put your tum at ease. The last thing you want to do is be stuck in your hotel room feeling uncomfortable while everyone else is out having fun!
Living by the motto, "TREAT YO'SELF" is inevitable while traveling, and I am certainly a supporter. If you are in a country that has a special delicacy, eat it!!! Don't let a strict diet get in the way of your vacation. My only suggestions are to eat when you are hungry and recognize when you are full.
Safe travels & happy eating!