Two of my major interests in life are eating delicious food and spending as little money as possible. So when I read about the Soylent project, which aims to produce an ultra-cheap food powder that meets all of a person's nutrition needs I was very much interested (about the ultra-cheap part and the nutritional needs meeting part, not so much about the tasteless powder part). My philosophy about food is much different than that of Soylent creator Rob Rhinehart, who states on his blog "In my own life I resented the time, money, and effort the purchase, preparation, consumption, and clean-up of food was consuming." Personally, I see the time I spend cooking as an adventure: an opportunity to learn and experiment. I rarely cook from recipes (although I do keep a notebook), and pretty much never eat the same thing twice. I see cooking as a kind of huge multivariable optimization problem with a complicated (and changing) objective function and no global optimum, but lots of local optima all over the place. I want to make food that is delicious, nutritious, cheap, and not monotonous, and I have fun trying to do that.
In a way (probably a lot of ways actually), maybe Rob Rhinehart and I are kindred spirits. I suspect when he was experimenting with different Soylent formulations, he experienced the same kind of excitement that I experience every time I walk into a kitchen with nothing but a hungry belly and a pantry full of lupins. I also have a lot of respect for the DIY Soylent community. There seem to be a lot of talented software engineers, and other creative people, over there applying their talents to nutrition optimization problems. Which is totally cool. But I think it would be even cooler if they could get past the idea of making food homogenate powders, and move on to formulating actual whole foods recipes (no blending or liquid reconstitution necessary) (and if one of them doesn't beat me to it, I plan to pursue this kind of project myself eventually).
There have been quite a few critiques of Soylent written. This one at PricePlow, is one of the more rational critiques, but I think the (anonymous?) author is still a bit more alarmist and inflammatory than necessary.
In a post on his blog, Rhinehart defends Soylent against some of its criticism, I think his best point is under the heading "Epistemic arrogance" where he mentions that synthetic diets have been successful already in certain contexts, and warns against "zero-risk bias", asking "How nutritionally complete is the average western diet already?" Unfortunately, Rhinehart also says some things that betray his over-simplified view of nutrition. Two statements in particular made me cringe. The first: "I am not sure if consciousness is reducible, but carrots certainly are." I won't make the case that carrots are a more complex life form than a conscious human, but I can tell you for a fact that there is not a scientist on Earth (or a textbook, or a publication) who can list every phytochemical found in a carrot. The technology to elucidate all of the components of carrots probably exists, but to actually do so would be a multimillion dollar effort (consequently if anybody is interested in funding such an effort, call me up [seriously!], I'd love to be on the team...). Rhinehart's other cringe-inducing statement was "we do know all the metabolic pathways of a human" when in fact human metabolism is a major area of research in biology, just ask any scientist in the pharmaceutical industry (or really any molecular biologist whatsoever). Researchers are still regularly discovering new enzymatic reactions and regulatory interactions (and yes even "pathways", although "pathway" is a kind of vague term, so I suppose one could come up with a definition that would make Rhinehart's statement true). My point is, insofar as Rhinehart thinks that plant composition and human metabolism are solved problems, he is incorrect. I suppose a better question would be "are they solved enough to allow people to confidently formulate optimally nutritious Soylent-like meal replacement powders?" He apparently thinks so. I'm less confident.
My personal opinion on the issue of Soylent nutrition, is that Soylent is probably a step above the much (and rightly) maligned "Standard American Diet", but a step below a well planned whole foods diet. The only way to know for sure will be to do large long term (like for a decade or more) longitudinal studies. I'd love to see a longitudinal study comparing a mostly Soylent diet with the SAD, and well established whole foods diets such as the Ornish Diet or the DASH Diet. Again, my hypothesis is that the SAD people would have the worst health outcomes, the Ornish and DASH people would have the best health outcomes, and the Soylent drinkers would be in between somewhere. But, of course, no one has done this study, so I don't really know, and neither do Rob Rhinehart, or any of his critics.
My biggest criticism of Soylent is the idea that it is cheaper (or even could potentially become cheaper) than healthy whole foods. In interviews with Vice, and The New Yorker, Rhinehart discusses how he thinks that Soylent could be part of the solution to the problem of world hunger. I think this claim is far more questionable than any of the claims made about its nutritional advantages. The problem with Soylent is a matter of thermodynamics. Soylent is a highly processed food. It takes more energy to process a food than to not process it (an exception may be if an unprocessed food has a lot of water that is lost in processing, in which case fuel savings from shipping the lighter processed food compared to the heavier whole food might make up for the energy spent in processing).
According to the label, Soylent contains Maltodextrin, Rice Protein, Oat Flour, Vitamin and Mineral Blend, Gum Acacia, Soy Lecithin, Salt, Xanthan Gum, Sucralose. Let's focus on three specific ingredients Maltodextrin, Rice Protein, and "Vitamin and Mineral Blend".
Maltodextrin is a polymer of glucose. It is manufactured from starch, which is a glucose polymer commonly found in grains, such as rice (the particular maltodextrin they use in Soylent is from tapioca, but they could just as easily make it from any other starchy plant).
Rice Protein is a polymer of amino acids. It is also (believe it or not) commonly found in rice. To isolate it from rice takes energy.
Vitamin and Mineral Blend contains a precise ratio of vitamins and minerals. I do not know the details of how all of these vitamins and minerals are produced. It is likely that the vitamins are isolated either from plants, or from yeast or bacteria cultures (that are fed by plant carbohydrates). Whatever the case, to achieve precise ratios, energy must be spent to isolate the vitamins and minerals from their original sources and recombine them into the blend. Whole grain rice also happens to have a good (but not complete) complement of vitamins and minerals.
Based on the above analysis, it's not hard to see that the manufacture of Soylent involves taking rice apart into its constituent components, then mixing those components back together again along with some other stuff to fill out the nutrient profile. All of this begs the questions: "Why bother going to all of the trouble of manufacturing Soylent?" and "Wouldn't it be easier just to eat rice along with something having a complementary nutrient profile, such as beans, and maybe a fruit or vegetable?"
In the Vice interview Rhinehart makes a telling statement: "Soylent can largely be produced from the products of local agriculture,
and at that scale, it's plenty cheap to nourish even the most
impoverished individuals." What he apparently doesn't realize is that there is no need for the "products of local agriculture" to be converted into Soylent before people eat them. People can (and do!) eat them just as they are. In some cases their diets are deficient in certain important vitamins (which ones varies among region), but one way or another, the missing vitamins will have to come from a plant (or from a yeast, bacteria, or animal, all of which use plants as food sources), and it will be more efficient to eat the vitamin source directly than to first convert it into Soylent.
This is my fundamental disagreement with Rhinehart, he thinks that post-harvest industrial processing of food makes it cheaper. In his words (again, from the Vice interview) "I think it's possible to use technology to make healthy food very
cheaply and easily, but we'll have to give up many traditional
foodstuffs like fresh fruits and veggies, which are incompatible with
food processing and scale... I don't think we need fruits and veggies, though—we need vitamins and
minerals. We need carbs, not bread. Amino acids, not milk."
Myself, I think post-harvest industrial processing of food makes it more expensive. It is already possible to make healthy food cheaply and easily! Cheap, healthy, food literally grows on trees!
So, my (highly erudite... cough...) verdict on Soylent is that it is (necessarily) expensive, but probably not dangerous. The most likely scenario for Soylent to contribute to alleviating world hunger would not be if the poor people themselves eat it, but if it can manage to displace meat and luxury vegetables in the diets of the rich, thereby improving land use efficiency by causing a shift of land from livestock and livestock feed production to production of nutrient dense, high yield plants for humans to eat.
A meal of Soylent currently costs about $3 (some of the DIY people claim formulations that are down to about $1). What follows is a recipe for a healthy (although admittedly not "nutritionally complete", but I'll try to work out something along those lines for a future post just to prove that it can be done) meal with a total cost somewhere between $0.50 and $0.80 or so per meal.
I call this "Rice and Sprouted Beans". Sprouted beans are more nutritious than unsprouted beans, having better amino acid profiles, higher levels of vitamins, and fewer anti-nutritional factors like phytates. If making this recipe not on an extremely tight budget, I'd recommend adding some carrots and broccoli, and something acidic (for flavor) like a few tablespoons of vinegar or lime juice.
1.5 cups rice (I used white rice, you should use brown rice)
1 saucepan bottom of beans to sprout (a 1:1 ratio of lentils to mung beans works out well I also added some lupins because I have a bunch)
3 tbsp of oil (I used Canola)
Iodized Salt (to taste)
Soak and sprout the beans (3-5 days)
Pan fry the sprouts in oil (or you could steam or simmer them, or even use them raw, but I recommend cooking them somehow)
Cook rice in salt water
mix everything together
My price estimate is rough, but dried lentils, mung beans and rice can all be acquired for $2 or so per lb. All together, I used less than 1 lb of dried ingredients, even factoring in the oil and seasonings (and stove energy), the whole pot of food is no more than $2. Again, guesstimating (sorry for not being scientific here, I'll weigh out my ingredients and save my receipts next time...) there are between 1500 and 2000 calories in this pot, which is 3-4 500 calorie meals, making the price per meal about $0.50 to $0.67.
For a cheap beverage, go with tea, or herbal tea (or just water). It's not hard to find bulk tea for less than $10 a pound (for example, here), assuming 2 grams of tea per cup, that works out to less than 5 cents a cup. I like hibiscus tea because it has lots of vitamin C (and is delicious).