I learned about Veg Visits on my most recent travels, a home sharing platform similar to airbnb, that allows you to stay at houses with vegan / vegetarian kitchens.
I did not use it however, so I can't speak much to its ease of use or successfulness.
I travel quite a bit and for me using apps like Happy Cow ,which locates veg*n restaurants near you, has been very useful. You can try using this kind of apps to look for something that is both healthy and suits your tastes.
Personally I don't focus much in the healthy eating aspect when I travel. I prefer enjoying the local food and discovering new dishes ...
I'm vegan and travel the world a lot. Some of my advice:
I always bring a bunch of protein bars with me
I find out the word and definition of 'vegan' in the language(s) where I'm travelling
I go to Subway, Whole Foods, or similar chains when I'm not sure (assuming they exist)
I buy a lot of fresh fruits / veggies that can be eaten raw (and I try to find ...
Maybe you can keep a small supply of whole grain snacks with you, like roasted grams, peanuts. You can also keep some dry fruits with you. These will supplement your "junk" diet on the road.
In restaurants/eateries try ordering stuff which is easy to make, like vegetable sandwiches. They will be less likely to be stale/unhealthy.
Also visit local shops...