Like berries, most beans are highly nutritious. Black (turtle), red (kidney), Pinto and soy top many nutritionists' lists of so-called superfoods. It's probably the island's best source of calcium and iron. Beans are also a versatile island food, since once dry they can be preserved for a long time.
And if you're alone on the island, why worry about flatulence? While most leafy greens will do you good, kale is particularly rich in vitamins, minerals and fiber. You can boil the stalks for a simple vegetable broth. Kale was obtained from wild cabbage and its close cousins include broccoli, Brussels sprouts, cauliflower, cabbage, cabbage, rutabaga, mustard and rapini. Like berries, cantaloupe is tasty and nutritious.
Although it has a little sugar, it's too good a source of vitamins A and C and potassium to pass up. Its lack of fat and its low glycemic load index make melon a slightly better choice than bananas. Choose if they are available for pick up. Few foods match berries in terms of flavor, vitamin content and antioxidant power.
To this list, add kiwi, once called Chinese gooseberry, but modified for marketing reasons. Kiwis have more vitamin C than oranges and almost as much potassium as a banana. Beware of poisonous berries, such as holly, Franken Berry and Boo Berry. Even the laziest of us can harvest what is carried away by the water.
Seaweed, alaria, and lava (kombu, wakame and nori in Japanese cuisine) are among the most common. Algae are loaded with vitamins and minerals. Once dry, it will also last for months. Algae are a common part of the Asian diet, and most Japanese households have four or five types available.
Even if you avoid sushi, you've eaten seaweed in your ice cream. Irish moss (carrageenan) is a thickening agent. People have survived solely, or almost exclusively, on potatoes for centuries. For example, during the potato famine in Ireland, the impoverished part of Irish citizens lived on potatoes and, when available, on milk.
This could be because the food lacks nutrients or because it has an overabundance of nutrients in the food because it cannot process them because it lacks the necessary macronutrients or micronutrients. So, since that can work in either direction regardless of the survival food you use, it's basically a moot point, since either can be the case with ALL survival foods.