Disregarding vitamin pills and concoctions like soylent, what could the essential human diet made up of minimally processed foods look like? A diet, that to the best of our current knowledge, would enable a human to live a healthy life not shortened by malnutrition. I mean food combinations like: eggs, broccoli and almonds; or liver, kale and potatoes. Things that one could walk out of any regular supermarket with.
I’d imagine people must have considered this for various reasons, but my google-foo was too weak to turn up anything aouthorative looking on the subject.
Depends on your definitions of “malnutrition” and “minimum.”
By one interpretation of the question, any combination of real foods that hits daily calorie requirements for weight maintenance that meets RDA would meet the requirements of 97–98% of healthy individuals in every demographic in the United States by definition.
I’ll use the smallest number of ingredients as a minimum. I’ll list each ingredient and which nutrients they cover.
Salmon. Covers protein and fat as the necessary macronutrients. Vitamins include B3, B6, B12, and D. Also a fair source of iron and vitamins B1 and E. If you include canned salmon with bones that would cover calcium as well.
Spinach. Covers iron and vitamins A, C, and K. Also a fair source of magnesium.
Avocado. Covers magnesium, potassium, healthy fats, vitamin C, and riboflavin.
If the question is being able to live off of the least variety of foods potatoes as the near exclusive backbone comes close. Amazingly it is a complete protein source and 2000 calories of potatoes would provide enough protein for an average person. It’s not quite adequate for all micronutrients but a small amount of other foods thrown in, maybe a bit of kale and almonds every so often (both micronutrient dense and in complementary fashions with almonds providing some essential fats), would fill the gaps fine.
Fortunately, a number of nutritionists put a lot of work into this question in the UK in the late 1930s, and came up with, broadly speaking, lots more potatoes, vegetables and bread, and a lot less meat (which is also a less nutritionally productive use of land, given the size of the population to be fed). Some foods were fortified with additional vitamins (bread and margarine), and rations were varied for people in heavy work, expectant mothers, children and so on. But if you want an idea of what was pretty well the minimum by the end of the war:
There are no vegetable sources of vitamin B12, without which you’ll become anemic or develop problems with your nervous system. Bread made with milk or eggs might contain enough B12 to prevent this, but this diet would also be very low in protein, calcium, iron, vitamin A, and a bunch of other nutrients.
When I was in college I took a course on linear programming, which is a form of mathematical optimization for certain types of problems. The professor told us that one of the first uses of linear programming was to figure out the diet that provided complete nutrition for the least cost. I asked the prof what the answer turned out to be, and he said, “Lots of navy beans.”
It’s interesting that molybdenum deficiency is the one thing stopping you from living on just potatoes and milk. Legumes of all kinds and nuts are good sources of molybdenum so you could also live on Potatoes, milk and green peas (or nuts instead of green peas etc).
I suspect Potato curry dhal would also be nutritionally complete since many of the poorest people in india do in fact eat nothing but this for every meal. It’s only three items rice, potatoes, lentils and the curry powder which I guess could be considered cheating. Would be a hell of a lot tastier than living on potatoes, milk and oatmeal however !
Lentils are possibly the best molybdenum source there is but besides the spices there is (thankfully for nutrition purposes, as you need a fat source) an oil, often ghee, used in it too.
Still need the B-12 source. B-12 deficiency is in fact a common occurrence among the poor of India. My suggestion fell short there too. Dairy did it in Cecil’s. Fermented dairy is higher than plain dairy (the bacteria fermenting it produce it) so a bit of kefir or yogurt would help. Using a B12 fortified rice would do it too if that’s not considered cheating. Children in poverty in India also tend to be iron deficient even though potatoes theoretically might have enough.
Or stick with mine and eat even only 3 oz of clams or liver every other week. Huge B12 sources and lotso iron to boot.
Seems like rice is a very bad choice if we’re going for a minimum number. Yeah, poor people all over the world eat it every day but that’s just for the carbohydrate calories, it has very low levels of other nutrients.
People all through the ancient world often ate little more than bread and wine. You’d need another source of complete proteins and fats though.
Looking up potato, I was shocked at how much vitamin C it has. Potato and whole milk yogurt are probably your best 2 food option.
Everybody’s answers are focusing on getting enough of every vital nutrient, but are we also considering whether we’re getting too much of something we shouldn’t? I’ve heard that salmon, for example, accumulate certain toxins like mercury; not a problem in moderation but not something to eat every day, either.
I’m wondering if that’s problem with any of the other limited diets described here. Would any of them give us too much of something that would cause problems?
If a whole animal can be counted as a single ingredient, you can survive on all meat diets as long as you’re willing to consume the offal and certain parts of it raw.
There are a couple of modern day paleo people experimenting with all meat diets, some for up to 17 years now with no noticeable harmful side effects. The Andersons have even cut it down to just beef so if “a cow” is a valid entry, then the answer is just one.
A couple of people doing something is insufficient data for various vitamin and mineral deficiencies. I’d say better evidence for “whole seal” given the historic Inuit diet but they do have some variety of fish and mammals and also some fruits and vegetable matter on occasion and are a selected genetic sub-population.
An all-meat diet would have no fiber. While one could survive without fiber for a long time, in the long run it would be bad for you. Lack of fiber increases the risk of high serum cholesterol, diverticulitis, hypertension and colon cancer. It can also lead to constipation, which may not be fatal but is certainly unpleasant.