Historically, communities have lived on very simple staple diets, like the Three Sisters in the US. You can survive almost entirely on just maize, beans and squ

Historically, communities have lived on very simple staple diets, like the Three Sisters in the US. You can survive almost entirely on just maize, beans and squash. The Iroquois supplemented with foraged nuts and fruit, plus hunted/farmed meat (which also doubled up as a leather/material supply). https://ojs.ethnobiology.org/index.php/ebl/article/view/721/413 https://ojs.ethnobiology.org/index.php/ebl/article/view/721/... Also potatoes are almost complete if you get sunshine for your vitamin D, but you'd be deficient in at least B12. I think most wild animals eat multiple things so it's not really fair to try and find a single food that fits. On changing diet, your body becomes more sensitive to deficiencies. If you're lacking in calcium, for example, and you break a bone, it's a lot more serious at 75 than it is at 25. The NIH recommends a slightly higher calcium intake in young people (for development) and over 50s (for preventative maintenance). Maintaining a young person's RDA your whole life wouldn't do you any harm though. https://www.bones.nih.gov/health-info/bone/bone-health/nutrition/calcium-and-vitamin-d-important-every-age https://www.bones.nih.gov/health-info/bone/bone-health/nutri... In the animal kingdom there's the concept of food chains/trophic levels. This is why ecosystems are fairly fragile if a provider species is removed, e.g. by extinction. Humans have learned to adapt to wildly different resources, and we have thousands of years of knowledge and culture about how to prepare food in a way that's nutritionally beneficial. There are several "staple" human foods which we've learned to eat, like cassava, which contains cyanide when raw.