I was browsing through discussions of that blog post on reddit, and someone pointed out that his formula has inadequate fiber. One batch has 1500ish calories from macronutrients (carbs/protein/fat), and only 5g of fiber. The daily recommended intake for fiber is 38g per day for an adult male, so if you're only consuming Soylent, you'll want to increase the fiber per batch dramatically.
You're absolutely right. I've had a spot of trouble finding a source of fiber that won't expand and turn my version of soylent into a gelatin.
As I understand it, Lent is a holiday where we celebrate the scientific method by changing exactly one variable in our lives for 40 days. This seems like a convenient Schelling point for rationalists to adopt, so:
What variable are you going to change for the next 40 days?
(I am really annoyed I didn't think of this yesterday.)