I've gone on the diet that Giles mentions (Eat to Live by Dr. Fuhrman) and I've also had a significant amount of weight loss, but none of the other benefits Giles experienced (as far as I could tell).
There's actually a meal-replacement shake called Shakeology that is made from all-natural ingredients (among others, I'm sure). The two problems I had with trying to replace one meal a day with a Shakeology shake are 1) at $5 a shake (just for the powder), it's really expensive, and 2) after a week or so, I would get ravenously hungry half an hour after drinking the shake.
It would be interesting to compare Soylent and Shakeology on a vitamin or even chemical basis.
I read this as a thinly veiled "eat whole foods" argument. Same criticism applies to such arguments as was voiced in previous articles about soylent. Just as a simple counter example, I don't like tomatoes and therefore don't eat them, so far I'm doing just fine, so clearly whatever "phytonutrients" exist in tomatoes, the human body clearly doesn't "need" them.
I'm still far more interested in whatever the results of the Soylent guys experiment turn out to be than whatever the results of this guys fad diet turn out to be because at the end of the day, what's being done with Soylent is at least marginally scientific in nature.
Most of my college meals consisted of pizza, ramen, and soda. The human body does pretty well with the shit I often give it. If someone wants to hack their body to improve their health; I'm all for it.
Birthday parties are very strongly correlated with living longer. Party every day, you'll never die, right?