Since you are on a carb restricted diet, I assume you are a type II diabetic.
By necessity you will have some carbs on board.
If you use exogenous insulin, you will need some fast absorbing carbs for when you go low. A small sealed Jar of honey works well, Candies are a magnet for moisture.
If you use no exogenous insulin and never go low, restricting unnecessary carbohydrates is wise but challenging.
Canned items, labels removed and cans marked with indelible marker, then varnished are useful but heavy and bulky.
Green beans, spinach, canned chicken, Asparagus, mushrooms (also available dried at Asian groceries), kale and Tomatoes.
Dried and sealed in Zip bags or vacuum bags even better, Non sweetened jerkey, coffee, stevia in dry and liquid form (No
cheap stevia as they float it in Dextrose and then say "It's not sugar!" Chana Dal (available at Indian Groceries), Quinoa.
The last 2 are carbs but at the lowest glycemic end possible and need to be consumed in strict moderation.
Sauces: in small factory sealed tubes and bottles. Worcestershire, soy,
fish sauce, ketchup (look for low/no sugar added) Miso paste for easy soup, bottled lemon juice, Tabasco/pepper type sauce, canned tuna (no labels marked and sealed), canned salted butter, sealed bottles of olive
oil, Mustard.
Spices, cumin, basil, garlic, oregano, paprika, black pepper and
salt etc. Do not
cheap out on air tight containers.
cabbages, apples (limited quantities), Lemons can survive a while unrefrigerated.
Carolyn Shearlock and Nica Waters excellent podcast,
The Boat Galley has excellent provisioning broadcasts as well as some diabetic information.
Just a few personal ideas. No
medical advice offered.