Twice a day, I pour my dog a bowl full of kibble, a specially formulated blend of barley, lamb, herring, and few other goodies I'm told will fully meet his nutritional needs. Sorting out my own nutritional needs is a bit more complicated. As much as I appreciate the variety afforded me by the bounty of fruits, vegetables, meats, and other foodstuffs around me, there are days when pouring myself a bowl of kibble (formulated to the human palate, of course) seems quite appealing.
After the time we're weened, however, it's uncommon for humans to subsist on a single foodstuff. Where once we dreamed of food pills to satisfy all of our nutritional needs, Futurama's Bachelor Chow has become a dark joke. But why isn't human chow an option for those who want something cheap, nutritious, and bland?
It's worth noting from the start that at various times and places in human history, the human diet has been much simpler. Certainly those of us in the modern world with the means and the access are spoiled for nutritional choice. Even in recent history, inhabitants of Western countries have seen their diets stripped down to bare, routine essentials. Food scientist Elsie Widdowson advised the British government on food-rationing during World War II, claiming that bread, cabbage, and potatoes contained all the nutrition the human body needed. Potatoes and milk were famously mainstays of the Irish diet in the decades leading up to the Great Famine, although these staples were supplemented with other foods. (Milk and potatoes do provide an impressive nutritional profile, but an exclusive diet of the two will leave you with some significant deficiencies.) High-calorie food mixes like pemmican have kept North American natives, fur traders, and explorers going in extreme conditions. And in prisons, incarcerated people are often fed cheap and simple fair, from the rice and bean kongbap historically fed to Korean prisoners to the Nutraloaf used a punishment in US correctional facilities (more on those later).
But the late 19th and early 20th centuries gave us dreams of better nutrition through chemistry. Jules Verne's 1889 speculative piece "In the Year 2889" (which was likely authored at least in part by Verne's son Michel) envisions a highly processed future of food:
The discovery of nutritive air remains in the future, but in the meantime men today consume food scientifically compounded and prepared, and breathe an atmosphere free of the microorganisms that once swarmed in it; hence they live longer than their forefathers and know nothing of the innumerable ailments of olden times.
Hugo Gernsback's Ralph 124C 41+ imagines that both appetite and eating would be carefully controlled. The humans of 2660 go to restaurants where they first inhale a gas that stimulates appetite and then eat dishes that have been liquefied and prepped for exquisite flavor with minimal mastication involved. Warren Belasco, author of the book Meals to Come: A History of the Future of Food, suggests that the industrial growth of the Victorian Era and the space-racing excitement of the 1960s and 1970s would be more receptive to the idea of technologically processed foods than those of us raised on post-apocalyptic scenarios where humanity falls due to our reliance on technology.
So let's start with the early folks who headed into space and their processed foods.
Mary Roach has a fantastic overview of early attempts at developing the perfect all-purpose astronaut food in her book Packing for Mars. Foods designed to be consumed in space have to meet a variety of needs, some of which don't concern those of us planted firmly on Earth. In addition to being nutrition, the food must be easily stored onboard, easily eaten sans gravity, and ensure astronauts don't suffer from an excess of gas or bowel movements. (Roach notes that the checklist for astronaut food isn't unlike the checklist for pet food: palatable, easy to store, and easy on Fido's tummy.)
The current trend for space cuisine is to give astronauts something of the taste of home. In variety, appearance, and packaging, the food eaten aboard the International looks more and more familiar. But in the early days of manned spaceflight, you were more likely to see a tube of edible goo than a cracker. Dietitions at the Aerospace Medical Research Laboratory and the School of Aerospace Medicine tried to cook up liquid diets that would be both nutritious and easy to consume on the go. In a 1965 article for the Lodi News-Sentinel, Dr. Norman Heidelbaugh, a SAM food technologist, defended the specially formulated liquid diets, saying, "Because it is chemically defined, technologists know exactly what it is in it and what it can do for astronauts." Comically, Roach cites one MIT nutritionist, Nevin S. Scrimshaw (who was a pioneer in nutritional supplements and malnutrition-fighting foods, if not the palatability of such foods), who said at a space nutrition conference that:
Persons with other worthwhile and challenging things to fill their time do not necessarily require bits to hold in their mouth and chew or a variety of foods in order to be productive and to have high morale.
According to Roach, chewing was precisely what astronauts missed. Plus, the liquid diets ranked low on the palatability scale—although at least one was reborn as a commercial convenience food: Carnation Instant Breakfast.
The daily realties of space travel, though, might have actually worked against the popularity of liquid diets among astronauts. That 1965 Lodi News-Sentinel article claimed that the astronauts longed for real food as a mental break from the monotony of work and sleep. Perhaps, contrary to Scrimshaw's claim, holding bits of food in their mouths is precisely what astronauts, even more than the rest of us, require.
Nutrition for Non-Eaters
There is, on the other hand, a whole class of terrestrial people for whom the question of eating is moot. While aerospace nutritionists were trying to formulate the perfect space diet, Dr. Stanley Dudrick and his colleagues at the University of Pennsylvania were working to feed the unfeedable. There are a variety of reasons individuals need nutrition that bypasses their digestive systems: they're unable to absorb nutrition properly through the usual channels; they've had part of their stomach or intestines removed due to illness or injury; they are temporarily or permanently unable to swallow; or, they're simply unconscious. Such patients were at risk of death from malnutrition.
But in 1964, Dudrick announced that he and his colleagues had raised six beagle puppies for 287 using what is now termed Total Parenteral Nutrition (TPN). Patients receive a mixture of glucose, amino acids, lipids, vitamins, and minerals fed directly into the veins. In 1966, Dudrick successfully tested his method for TPN of six patients with terminal conditions.
Although TPN has been life-saving, this isn't an ideal method of nutritional intake. Long-term use of TPN can cause fatty liver and problems with the gallbladder, and simply employing chronic IV access puts users at risk for infection, blood clots, and other complications.
There are also liquid oral nutritional products for individuals who can absorb nutrition through their digestive system, but suffer from lack or appetite or have difficulty consuming or digesting solid foods. And here we do get laboratory-formulated complete nutrition in a bottle; after all, there are people who subsist on products like Ensure Plus. (Although the Abbott Laboratories website will tell you that Ensure Plus is for "interim sole-source feeding.") But these products aren't inexpensive and should be used under a doctor's supervision.
Ready-to-Use Therapeutic Foods
Ready-to-use therapeutic foods (RUTF), are calorie-dense foods used by famine relief initiatives to treat malnourishment. If we're talking about adapting a food for consumer use, therapeutic foods have certain advantages: they are hopefully inexpensive to produce, requiring little to no preparation, and nutrient-rich. The preparation of therapeutic foods like Unimix, a powdered mixture that can be cooked into a porridge, is considerably less problematic in regions with access to clean water than in many of the regions where it is employed, where contaminants in the water will be transmitted to the food.
That's part of the reason why there's been such a stir over Plumpy'nut, a paste made from peanuts, vegetable oil, powdered milk, powdered sugar, vitamins, and minerals. The paste is by all reports tasty, can be eaten straight out of the pack, and has a shelf-life of two years without refrigeration. (It's also used in regions with low incidences of peanut allergies.) And the formula is simple enough that it can be manufactured in many of the regions where it is being deployed, using local peanuts from those regions. (Although many humanitarian agencies have raised an anxious eyebrow toward Plumpy'nut manufacturer Nutriset, which has filed a patent on the substance.)
But don't go replacing all the food in your house with Plumpy'nut, peanut lovers. While fortified with nutrients, Plumpy'nut isn't designed for everyday consumption; after all, it's meant to rehabilitate severely malnourished children and support rapid weight gain. For severely malnourished children, a four-week course of Plumpy'nut is often recommended, and even then it is supplemented with grain-based foods like Unimix.
Breast is Best
If you're looking for a nutritionally complete food that wasn't cooked up in a lab, you need look no further than mother's milk. As we've mentioned before, human breast milk contains all of the nutrients a human needs to survive. Babies live off of it, and while adults don't, they could in theory.