A few members of the PhDish have started using Soylent, a nutritional supplement drink designed to include most of your basic dietary needs, theoretically able to replace some meals and packaged into a cute white bottle. As a person who spends a large part of her day fantasizing about lunch (and then enjoying consuming it), the idea of having a meal-in-a-bottle baffled me. So, as any good scientist would, I decided to investigate the draw of nutritional drinks like Soylent by asking our PhDish writers and a doctor at Mt. Sinai hospital (who also uses the drink) about their experiences… and ultimately trying it myself.

Here’s what I found:

Soylent 1.5. Credit Ryan Ozawa on Flickr.

First – what the heck is it? From their website, I learned that Soylent 2.0 is a mixture of soy protein, algal oil (for fatty acid needs), isomaltulose (a beet-derived sugar), and a combination of vitamins and minerals. It is vegan and lactose and nut-free, but not fully organic, kosher, gluten or GMO-free. Each bottle is 400 calories, with no trans fat or cholesterol. Soylent 1.5 (editor's note: updated to v1.6 since the time of these interviews), also available for purchase, is a similar product in powdered form that requires blending with water.

To learn more about it, I asked our interviewees about what nutrional supplement drinks are like, as well as the science implications. (I have also included a summary paragraph at the end of the article.) Michael, Sanchit, and Amy use version 2.0, while James uses v1.5.

The Soylent company has no knowledge of or financial backing of this article.

The When and the Why

Everyone I interviewed has been using Soylent in some capacity for at least 6 months, and use it primarily for convenience and cost. Here are their specific comments:

Dr. Michael Schreiber (PhDish writer/editor): Both my spouse and I find the convenience of not having to plan breakfast and lunch to be a major benefit. We also save money by not eating out as much for lunch, which means we can spend more on nice dinners together.

James Lohner (PhDish writer): The idea of breaking [nutrition] down into its smallest units and building from there is intriguing. Also, knowing I have a decent balance of micronutrients, not too much simple carbs, and adequate fiber (probably the biggest challenge in a ‘normal’ diet).

Amy Jobe (PhDish writer/editor): Regarding its easy digestion, I have a sensitive stomach. A lot of foods give me stomach pain, as does eating quickly or eating after waiting too long between meals. Before I used Soylent, on particularly bad days, I’d be reduced to eating bread and chicken broth. But Soylent is very mild and I can drink it at my own pace, so I can stay mostly pain-free and still get balanced nutrition. Last, Soylent is so convenient: one bottle will fit in my purse in case I get hungry while I’m out. The best part for me is that Soylent makes it easy to save money. While I’m relying on Soylent for a given period of time, I don’t even have to think about how to avoid going over budget.

Dr. Sanchit Gupta (doctor at Mt. Sinai hospital): I had been looking for a cost-effective, reliable snack. Soylent is more filling and cheaper than all the granola/snack bars I could find.

Soo…. what’s it really like?

Amy: It’s more sweet than savory. Its texture is like that of any other meal replacement…you can also mix Soylent with other drinks, even coffee, to change its taste. I have to admit, though, I’ve asked several friends to give it a try, and after a sip, most people say that it tastes all right but that they wouldn’t drink it again!

James: The flavor is essentially cake batter, if you left out most of the sugar. The texture is much improved since they’ve incorporated granular fats into the powder mix (they used to be supplied in a separate bottle of algae oil).

Michael: It tastes a lot like milk that has had cereal like Cheerios blended into it. It has a very breakfast-like feel to it.

Sanchit: Soylent doesn't really taste like anything and has a thick texture, thicker than milk, but not as thick as a smoothie. The lack of flavor doesn't make it appealing, but also makes it harder to get sick of.

Is it weird to not chew your meal?

Sanchit: I use Soylent primarily as a snack, so it's easier for me to think of it as a shake for the road. I will substitute it for breakfast if I'm in a big rush, and it certainly is disorienting not to eat solid food for a meal.

Amy: I want to first point out that I don’t often think in terms of ‘meals’ when I’m using Soylent, especially if I’m drinking multiple consecutive bottles. Drinking Soylent is more of a grazing activity for me. But, no, the lack of chewing doesn’t feel strange to me. I do wonder if not chewing can physiologically or psychologically affect my feeling of fullness, but I haven’t looked far into the research about this.

Michael: I don’t think so. It doesn’t bother me.

James: Not at all. I think most people have had a smoothie for a meal at some point. It’s not a big deal.

Any drawbacks?

James: The fiber/carb blend in v1.0 was brutal on my gut microbiota. For the week it took my system to adjust I was a constant source of noxious fumes. After the adjustment period there have been no drawbacks that come to mind.

Michael: We’ve encountered some spoilage with a few of our bottles of Soylent 2.0. Lugging massive crates of Soylent 2.0 up to our second floor walkup also is less than enjoyable.

Sanchit: Soylent 2.0, is a liquid and tastes better cold, which means it can be a hassle to store. Similarly, it doesn't travel well (can't take Soylent on planes).

Amy: After several consecutive bottles of it, if I don’t eat regular food between them, I get bored of Soylent and I want to eat something else. I feel a bit tested whenever I walk into the lunch room at lab clutching my Soylent bottle, and I can smell everyone else’s Chinese takeout or homemade leftovers.

Have you used meal supplements/replacements of any kind before? Slimfast, protein shakes, etc? How does this compare? In what way can Soylent improve (nutrition, appeal, etc.)?

Michael: No, I haven’t. I think Soylent could come down a bit more in price, improve its quality assurance, and perhaps add some flavors. I also think Soylent could lower its glycemic index a bit further from where it is at now.

James: In college, I broke my jaw and was on a liquid diet for seven weeks. You get pretty creative with a blender after a while, but a lot of that time was Ensure, Slimfast, etc. Soylent lacks the flavor variety of the other offerings, but leaves me feeling full longer. Personally, I wouldn’t mind shifting some of the carb calories to fats and proteins, but I think they stand to gain more from a flavor perspective than a nutritional one. Releasing chocolate/vanilla/coffee/fruit flavors would go a long way to combating the flavor fatigue that is the one major drawback to Soylent.

Amy: I used to drink whey protein shakes after workouts in order to build muscle. I used them for a more specialized purpose than I use Soylent for, so I can’t compare them directly, but Soylent certainly tastes better. As nutrition research improves, I imagine that Soylent creators will tune their recipe accordingly. Everyone’s nutritional needs vary, and Soylent’s makers will never create infinitely diverse recipes, but it would be great for them to develop specialized compositions for male vs. female adults, and teens.

Sanchit: Compared to unflavored protein shakes [I’ve used before], Soylent tastes pretty similar. The packaging can be cumbersome, since there is both an external wrapper and internal seal to the bottle top. Nutritionally I think Soylent is balanced, and provides a sustained boost through the day.

Let’s talk nutritional science. No meal replacement has ever been shown to be equivalent to actual food before, given the complexity of nutrition in food we don’t even fully understand yet and interaction with gut microbiota. What are your thoughts on this?

Sanchit: There is no processed food that should substitute for "real" food. A balanced diet is much more complex than any replacements, which cannot take into account variety of foods and impact of fresh fruits and vegetables, let alone the flavors that constitute the pleasures of eating and social benefits of eating with people. If someone's diet consists of frozen pizzas for every meal, Soylent may be an improvement. I'm happy to use it as a snack in between real meals.

Amy: First, Soylent probably isn’t complete in terms of micronutrients -- the compounds except for carbohydrates, lipids, and fats -- that we need but only in small amounts, because research on nutrition is always a work in progress. Second, recent research suggests that certain Soylent and any other foods are probably best eaten at certain times of the day or relative to certain activities; perhaps even certain components of food, the macronutrients – those carbohydrates, fats, and lipids – are best eaten at certain separate times of day. Soylent doesn’t come with instructions for when to eat it, and it can’t be separated into its nutritional components. And there are probably nutritional shortcomings in Soylent and other foods that we don’t even know about yet. Third, Soylent does not provide the daily recommended amount of water for an adult – even v1.5, which is blended with water – so users still need to drink water. Fourth, the recipes for Soylent 1.5 and 2.0 are calibrated for a maintenance diet of 2,000 calories per day, so if you’re trying to build muscle, or lose fat, and you need different proportions of nutrients, you won’t meet that need from Soylent alone.

In response to those shortcomings, I’d like to note that Soylent is not meant to be anyone’s sole source of nutrition. It even says in the nutrition facts for v2.0 – and I think this is very important – “While not intended to replace every meal, Soylent can replace any meal [emphasis Amy’s].”

James: The only things that I know are common deficiencies in western diets are vitamin D, some B vitamins for vegans, and fiber. Since Soylent hits all those bases, I’m not terribly concerned. I know I’m doing better in the fiber department than I ordinarily would. I’ve never experienced any symptoms of a nutritional deficiency since starting Soylent (although, I am rarely on a 100% Soylent diet for more than a few consecutive days).

Michael: I think it is a specious argument. People aren’t replacing some mythical idealized gourmet diet with Soylent — they’re replacing whatever mix of fast food and reheated, processed store bought food they normally eat with it. I can’t imagine a diet of Soylent is any worse than eating cereal for breakfast and going to 5 Guys for lunch. In fact, I suspect it is much more balanced and nutritious.

What about in terms of big picture? In what situations do you think Soylent would have the most benefit? One thought is to distribute it to areas in the world that have problems with malnutrition – but this has also been viewed as setting up a “second class” of people for food. Thoughts?

Amy: I’m not an expert, but it seems like Soylent is in a unique position to relieve so much of world hunger. It’s well known that hunger, on a global scale, isn’t a problem of supply (although it can be at the local level), but rather a problem of distribution. One region may not receive enough rain one year and be deficient in all types of food crops; another region may produce an excess of say, starchy cassava root, but lack good sources of protein, fat, and micronutrients; yet another region, like the US, might produce more than enough food but distribute it poorly and subsequently waste much of it. For regions like the first and the second, Soylent distribution might be a great solution because it’s relatively inexpensive, easily portable, and, importantly, because it has a one-year shelf life when unopened. I can see why some people might worry that people in need will be perceived as only deserving or having access to this food that is experimental, not glamorous, and admittedly not that delicious. But the problem of their survival so dwarfs the issue of their class; I can’t imagine keeping Soylent from these people out of worries about classism. The class issue is real, though; perhaps Soylent could act as a symbolic solidifier of class for these people who are already economically poor. I’m not sure what the solution to that could be.

I also think that Soylent could be of great use in nutritionists’ and dieticians’ offices and in eating disorder clinics. In the former case, it would be fairly simple to prescribe and follow diet plans containing at least some Soylent, and patients could easily learn about exactly how many calories of balanced nutrition yield different amounts of energy and feelings of fullness. Second, for those with eating disorders, the psychology surrounding disease and treatment is very complex for these real and physical illnesses. But Soylent might ease treatment for those who struggle to get enough nutrition, because it can be consumed in any amount at a given time, in any place, and it may not carry some of the emotional valence of traditional food. It’s also very simple to keep track of the number of calories consumed.

In terms of sustainability, Soylent’s nutritional sources come from as low on the food chain as possible – the fats in v2.0 are even derived from algae – and this minimizes its carbon footprint. Its packaging is also recyclable.

Sanchit: Soylent is probably ideally used as a snack rather than true meal replacement. Ready- to- use foods have been distributed for famine relief for years, mostly as supplements derived from peanut butter. The urgency of famine relief means that any possible source of nutrition should be utilized to maintain the population's health--, especially for children, who are most vulnerable. However, distributing foods in times of famine is no solution to the various situations and inadequacies that lead to that state.

Michael: I think absolutely giving it to people who are starving is a fantastic idea. I also think it is really questionable to tell a starving person they’re better off starving to death because of political correctness.

James: At the current price point (~$9/day), Soylent isn’t viable as a long-term food replacement for the world’s poor, but still could be useful to deal with temporary stresses on supply chains (especially since it can be dropped from height to hard- to- reach areas). Whether it will ever become cost- competitive with current subsistence diets depends on too many factors for me to comfortably speculate about. If it does, I would consider it an improvement on the current situation insofar as it provides choice to consumers. There are already many classes of people when it comes to food security. I don’t see harm in providing a more complete option to those who struggle to meet all their nutritional needs. I [see] the potential for this product have society-wide effects, whether that be access to safe food in disaster/humanitarian situations, or minimizing the carbon footprint of a subsection of our food supply, or avoiding consuming calories from factory-farmed animals.

Credit 玥視界 on Flickr. — Credit 玥視界 on Flickr.

The experiment and my two cents

After all that, I obviously had to try Soylent myself. I gave v2.0 a shot for a few days, using it in between regular meals as well as one breakfast replacement. It tastes okay but not great, must be served cold in my opinion, and is a valuable snack when there’s nothing else around. Oh! And it’s great for hungover mornings when nothing seems to be palatable. But, I think I love food too much to get into Soylent full-time.

Soy proteins also absorb isoflavones, molecules similar to estrogen (and unlikely to be separated during processing). Data is conflicting on the effect of isoflavones on human hormonal interference, but it’s possible that a diet composed largely of soy (in excess of most normal soy-containing diets) could have contraindications for patients with breast cancer, for example, or women undergoing hormone replacement therapy. It will be interesting to monitor the long-term effects of Soylent in these situations. Soylent also doesn’t contain compounds from spices (like curcumin from turmeric), which have long-term health benefits such as protection from Alzheimer’s and certain cancers, as well as antimicrobial properties.

TL; DR

Soylent is a balanced nutritional drink, and has a mostly neutral taste and texture. A true comprehensive diet is too complex to be substituted by Soylent (and it lacks some beneficial dietary components), but it is really good for snacks and some meals, especially if you’re using it in place of sugary breakfast cereals or fast food. Soylent could also be very useful for people with eating disorders or sensitive stomachs. While possibly too expensive to be a sustainable way to improve malnutrition in the world, it could help alleviate shorter-term famines due to its long room-temperature shelf life. It also has a relatively low carbon footprint!