1.) Travel with a cooler and bring your own healthy foods if possible.
2.) Planning ahead is always key. Prior to travel you should research different restaurants in the city you are going to and find healthy options so that when you arrive you know where to go. Remember that restaurants are in the business of making you what you want, so most are very accomodating to your needs. Order “off the menu” if you have to, and just make sure they know your restrictions.