Maintaining health while on vacation:
Whatever one's idea of health is - or healthy diet - if the area you are vacationing in doesn't provide it - you have to plan and take your food with you. Fortunately for Vegans and to some extent Vegetarians - dried beans, nuts, seeds, whole grains last for decades when un-tampered with and properly stored - and brown rice for about a year.
Then there's meat jerky for the meat eaters. But unfortunately - that's not nearly enough. Something the British learned when their sailors were stricken with Scurvy and chose to include limes on their journeys - while the Chinese kept dried mung beans on their ships to sprout (and thus provide Vitamin C and many other nutrients) for their sailors.
Moral of the story is:
Should be obvious