Quote in the article from Rob:
I look forward to being able to share some more quantified data here. We are setting up processes for gathering and sharing health data as it relates to Soylent consumption. However, for the time being we have had to focus on product development and distribution and have not yet had the resources to run the studies we have planned. However, many of our backers are savvy quantified self enthusiasts and health hackers. If you look around the Web, and especially discourse.soylent.me, you will see loads of health data and experience reports. I will let the users speak for themselves until we have more controlled data to report. Personally, I still use it multiple times a day and feel great.
That at least explains what happened to the rumored studies. I don’t think I had ever seen any official word on those either positive or negative until now.