No one food can provide all the needs of human adults in the long term. If you are determined to follow a single-food diet, potatoes are probably as good as anything else. Potatoes contain a wider range of amino acids, vitamins and minerals than other starchy foods, such as pasta or rice. However, no nutritionist would accept a diet based exclusively on potatoes, nor would they recommend a single coconut, kale, seaweed, or yogurt either.
The U. S. Dietary Guidelines recommend eating a variety of vegetables, grains, proteins, fruits and oils. Eating any of these foods on their own will soon lead to nutritional deficiencies.
Variety is important and in this case, it's vital. To get the most out of your potato diet, load it up with other healthy things like beans and berries. Most beans are highly nutritious and black (turtle), red (kidney), pinto and soy top the lists of so-called superfoods by many nutritionists. This will be your best source of calcium and iron on the island.
Beans are also a versatile island food since once dried they can be preserved for a long time. Kale is particularly rich in vitamins, minerals and fiber. You can boil the stalks to get a simple vegetable broth. Kale was obtained from wild cabbage and its close cousins include broccoli, Brussels sprouts, cauliflower, cabbage, collards, rutabaga, mustard and rapini. Cantaloupe is also tasty and nutritious although it's a little high in sugar.
It's too good a source of vitamins A and C and potassium to pass up. Their lack of fat and lower glycemic load index make melons a slightly better choice than bananas. Few foods match berries in flavor, vitamin content and antioxidant power. To this list add the kiwi which once was called Chinese gooseberry but changed 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, frankberry and bamboo berry. Even the laziest of us can harvest what is washed up on shore like seaweed, alaria and lavender (kombu, wakame and nori in Japanese cuisine). Algae are loaded with vitamins and minerals and once dry will last for months. Seaweed is a regular part of the Asian diet and most Japanese households have four or five types available. Eating just one type of food is not a long-term possibility as there is simply no edible product that can exclusively sustain a healthy adult. Breast milk is sufficient in calories but lacks protein and fiber which could cause liver and kidney damage if not supplemented with solid foods.
Kaleis an incredible superfood that helps you do everything from delaying age to fighting cancer.
A 100-gram serving of kale serves much more than the recommended daily amount of vitamin C (200%), vitamin A (300%) and vitamin K1 (1000%). However, kale has some problems such as absorbing too easily a toxic heavy metal called thallium which is a problem if you devour it in large quantities. Eating raw kale can also inhibit iodine absorption which could lead to hypothyroidism. Dried fruits and nuts provide calcium, iron, zinc, magnesium and potassium while being low in sodium. In addition dried fruits are high in fiber and low in fat while nuts are naturally an excellent source of protein.
The only problem is that there is no source of vitamin B12 and drying fruit eliminates vitamin C so you'll never get enough vitamin D or K.