Dear dietitian and nutritionist, what is the healthiest diet one can have while traveling?

I am about to embark on a backpacking adventure around Big Island Hawaii. I have about $300 a month to spend on food. What would be a good set of staples to be carrying with me? Are there forums or communities online that i can discuss this with in further detail? Thanks a million in advance. Love this community, and the information we share. Namaste.