A lot of this depends on how you intend to cruise
If you're motoring between ports
and don't mind spending 2.5GPH minimum, you can have enough refrigeration to do whatever you want. Well, honestly the leafy greens will still get old after a week, but mostly everything.
If you're sailing, and doing multi-week passages, you can forget about anything but a very small reefer, and even that's got a time limit.
You'll be going back to pre-1930s foods across the board. Canned food. Dried food. Grains, cereals, and legumes. The only modern tech that works is shelf-stable plastic bagged foods. Shelf-stable milk. Canned, smoked, or jerked meats only.
Fresh food and fruit you buy in port, where-ever you go, and whatever they have. You add that to your staples. Beans, rice, + plantains. Rice + Tuna steaks.
One minor problem you'll have if you want to eat fresh and organic is that in a lot of 3rd world countries, you're expected to be able to slaughter and dress your own chicken.
your boat in a foreign port as if it's a hotel
room is no different than any vacation
you've taken. World cruising, especially on a sailboat, isn't going to be reliably able to offer fresh foods underway, so you'll need to find those elements of your diet that preserve well the old fashioned way.
Let us know what you figure out! I'm always looking to expand our stock.