Well, get this. The entire concept of Soylent is geared toward weight loss. With the rare exceptions due to medical complications or genetic abnormalities (and I mean rare), the key to effective weight loss is about calories in vs out. Take myself as an empirical example. I am a type II diabetic and I weighed 315 lbs in August 2014. Soylent started shipping and I got my first box around September. Without adding any workout routine or needing a special formula that catered to my diabetes, I wieght around 285 lbs by March of 2015.
What Soylent provided me was a simple and effective way to gauge exactly how many calories I was taking in. The price and convenience were secondary benefits, but very important to me.
I started working out in March of 2015 and was able to start playing hockey again later that year. Currently I have gone through a 6 month period with no exercise due to two surgeries and am just this week starting back at the gym. And get this... I actually lost a little weight during that time. Granted, some of that is probably muscle, but I didn't blow back up to my pre-Soylent weight because I was still using Soylent during this period.
So exercise isn't even the best way to lose wieght. Ever heard the saying, "You can't outrun a bad diet"? It is pretty accurate.
I will concede one point, a higher protein content would be welcome, but I use a protein supplement that I mix into my Soylent powder and that takes care of that. The high protein version would be better served in the premade since it is kinda problematic to put powder in those bottles.