A real liquid diet taken with a grain of salt

Rob Rhinehart claims he has almost completely eliminated food from his diet. The 24-year-old software engineer has developed a drink he calls “soylent”– a chemical cocktail containing the essential vitamins, nutrients,  the body absorbs from food.

The name “soylent” was first used in a 1966 science fiction novel called “Make Room, Make Room!” This futuristic food source, originally made of soy and lentil, evolved into something more ghoulish in the 70’s film adaptation “Soylent Green.” In a future world plagued by overpopulation, soylent green becomes a means of ‘recycling’ human beings. Rhinehart doesn’t seem particularly troubled by the allusions, though. His mixture is actually sweet – “like thin cake batter” or “melted ice cream,” he wrote in a blog comment.

Last month, Rhinehart stopped eating entirely to judge the effectiveness of this total meal replacement. He consumed a few daily shakes and documented his feelings, recipe changes and blood work on his personal blog. The blog has now collected hundreds of comments from critics and eager participants alike, many vying for a spot in the next step of his experiment – a trial with six participants.

In a full month of not eating, Rhinehart claims to have felt better. In his blog, he wrote that his skin was smoother, his energy levels were up, and he didn’t crave the greasy street-corner Mexican food he usually did. He said he felt sharper mentally, with quicker reaction time and a 30 per cent jump on one online ‘brain-training’ tool. “It’s like finding a new partner you really care about,” he wrote. “When all your needs are met, you don’t have a desire to stray.” He now only eats socially, once or twice a week.


He’s not merely looking to survive – he’s looking for something “ideal.”

Toxicologist David Miller suggests these results may be overhyped. It’s not that Rhinehart exaggerated them – in a way, it’s actually the opposite. These results are quite normal.

“We eat too much,” Miller said. “Everyone would feel a hell of a lot better if they cut their calories.” Both he and Rhinehart also mentioned the body can survive for a very long time on very little. But Rhinehart is not merely looking to survive – he’s looking for something “ideal.”

A quest like this comes with its share of danger. Overdosing or underdosing on certain chemicals could have tragic consequences, Rhinehart hinted in an early blog post. He, himself, got sick at the beginning when he was adjusting and optimizing the amounts of raw ingredients in soylent. Now, with the six-person trial under way, he’s continuing to tweak the recipe for different physiologies. The three women had more trouble adjusting to it than the men did, he wrote.

Rhinehart has received a range of criticism – from highly critical (“you’re not getting any boron, and there is evidence boron is an essential nutrient!” someone commented, he told Vice Magazine) to more repulsed outbursts from naturalists and “foodies” insisting the body “can’t live on powders and chemicals!”


Miller: “Food is much more than the sum of the parts we know about.”

However dismissive Rhinehart may be of the latter criticism, Miller suggested there is weight behind it.

He used the example of lycopene, an antioxidant found in tomatoes that greatly reduces the risk of prostate cancer. Such a property creates tremendous incentive to take the stuff out of the tomato and put it in a pill – not unlike what Rhinehart has done. But a 2003 study published in the Journal of the National Cancer Institute found that the extract simply could not compare to the whole tomato. The risk of prostate cancer was significantly higher in rats that were fed the lycopene extract compared to those fed whole tomato powder. Though the lycopene is responsible for the decreased risk in prostate cancer, there are chemical mixtures in the tomato that impact its effectiveness.

In other words, there is something – some mixture in the whole food – that could not be accounted for. “To actually understand all of that would require so many resources that we don’t even try,” Miller added.

And this is just one example. Miller pointed out that there are many more studies on lycopene that support this finding, and lycopene is only one of a great range of chemicals that affect our health.

Rhinehart has already included lycopene extract as one of the “non-essential” soylent ingredients. Whether or not he’s accounted for all the body’s needs won’t be clear for a while – certainly not after one month, Miller said. The effects of more obscure ingredients like lycopene wouldn’t become evident for many years.

But the complexity of the experiment extends beyond what’s in the drink. There are also questions about mechanics to consider. How would an almost entirely liquid diet affect the function of the large and small intestine, which have evolved to process solid food? A few meals a week may be enough to maintain the system short term but opinions diverge after that. What about the microbiome, the vast population of bacteria in our bodies that outnumber our own cells by a factor of 10? Many thrive in our gut, nestle themselves in the fibre we consume, and play an essential role in our body’s function. Miller said they would absolutely be affected by this new kind of diet, but at this point, we cannot know how.

Considering the lack of oversight, the inherent risk, and the dilettante nature of the experiment, Miller is far from convinced that this is the best way to find out.

*Front Page Photo Courtesy of Vice Magazine

Comments are closed.