Travel can help create healthy habits and break the bad. I say "can," and not "will," because it really depends on what kind of travel you're doing. I'm not sure if going on a party cruise with an open bar and free buffet will really create healthy habits. Unless you're going with the intention to strengthen your discipline and will under the most tempting situations (if you are, you deserve an applause).
Travel presents an opportunity to get into the mindset of starting anew. New start in a new place with a new schedule is an optimal situation to start new habits.
Here are some of the healthy habits I picked up in India:
1) Becoming a smile initiator toward strangers. While in India, I became aware that I was a reactionary smiler. I only smiled when the other person smiled first as we crossed paths. I don't know why I became this way or if I had always been that way. I thought about this a lot and I think it has to do with vulnerability. The fear that your smile won't be returned, that it'd be rejected. But why waste time being fearful of stupid sh*t like that? Now, I smile. And I smile big. At anyone who walks by. And EVERY TIME it's worth it.
2) Not buying anything unless it is to replace something. When traveling, you carry what you own - the more you have, the heavier and burdensome your load. And once you start living out of a suitcase, you realize you're still happy (if not more happy) living on very little. Simple as that.
3) Only getting online when necessary. During travels, you're so busy being bug-eyed curious and child-like excited about experiencing everything around you that the internet becomes just plain grey. In fact, it simply doesn't cross your mind. And when you do use the internet, you really use it as a tool, not a way to pass the time or for entertainment. Bringing this way of thinking about the internet back home with me has made me a much more happy person.