I wish I could scrutinize but all my knowledge comes just from reading stuff on the internet and there’s absolute need of better and serious research on this stuff.
But since you’re working on the recipes then it can be useful to discuss.
As I previously said the current “weaknesses” of jimmyjoy-plennyshake appear to be these: too high protein content, many doubts about the GI, ratio of calcium/phosphorus, manganese too high (and maybe better source of omega 3 and rising the amount of vitamin D).
There was in Italy an article on an important newspaper (don’t know if it was just online, though), the guy drank only Jolent for a few days, felt sick, gave an overall very negative review and included some comments from medics that warned about a too high protein content.
The article was pretty bad, but this just to say the high protein content is something that can be superficially seen a a negative, possibly bad for the health. Now, if you actually read online about protein and kidneys you always read there no real “upper limit”, and that they could never find a proof that a high intake of protein is bad, even in the longer term.
Still, the overwork of kidneys with a high protein intake is a fact, and it is a serious risk under certain conditions, like diabetes. In general if you are not an athlete it makes little sense to have a so high protein intake.
This is what Rhinehart a few weeks ago with the presentation of Soylent 1.6:
https://www.reddit.com/r/soylent/comments/4sou6w/i_am_ceo_rob_rhinehart_ama/d5azri3
"Not all carbs are equally bad or good (soylent is low GI) and 20g protein / serving is quite a lot. There is also a risk of nitrogen imbalance from too much protein in the diet."
This after Soylent rose the amount of protein from 1.5 to 1.6, now it’s 105g compared to jimmyjoy-plennyshake 137g. But take Queal and Huel as examples and we have 148g and 146.7g. That’s what I mean when I say competitors have their own big issues. Both Huel and Queal go even higher that jimmyjoy-plennyshake, and Huel is even higher than 148g, because you have to count is compared to 2000kcal instead of the 2100 of Queal and jimmyjoy-plennyshake.
And if you go look that guy that has a blog, using JUST jimmyjoy-plennyshake for the past six months as an experiment… If you dig into the details you see he’s fine, but he still has certain issues that show in his bloodwork and they seem all tied to kidney activity, intake of vitamin D and dehydration. He explains a bit of this if you read his blog too.
All this seems to point to problems in the same areas: too high protein content, issues with vitamin D, and issues with Calcium/Phosphorus balance. All of these converge in the activity of the kidneys, and the use of Calcium depends on vitamin D. So all these small imbalances in the jimmyjoy-plennyshake recipe tend to lead to a single overall issue.
This is all made worse because jimmyjoy-plennyshake is structured around the idea of three meals a day. That means the high protein concentration goes in all at once, and again it’s the kidneys that have to deal with that. It might not be an health issue, but it certainly causes stress that we could do without, striving for a better recipe. At least Soylent is 4 meals, and 2000 calories, that means 25g of protein at once, compared to the 45g of protein in jimmyjoy-plennyshake.
So, if I can give a suggestion this is what I would focus on. Lowering protein under 100g a day to lighten up stress on kidneys, see if there’s a way to reduce the phosphorus levels, increase a little bit the amount of vitamin D.
The thing about vitamin D is that it’s mostly based on exposition to the sun, and adding it in the diet probably doesn’t have a substantial effect. But most recommendations (Italy for example sets it at 10ug) exceed that in jimmyjoy-plennyshake and there are absolutely no negatives about rising it even as high as 20ug. It’s one of those cases where adding more than necessary is not a risk. And because of other issues around Calcium specifically in jimmyjoy-plennyshake might mean that lots of vitamin D in jimmyjoy-plennyshake might be a very good thing to balance it all out.
And of course lowering the GI. There were always concerns about jimmyjoy-plennyshake using too much maltodextrin, and it’s a fact that a lot of effort in the recent Soylent formulas was all about lowering the GI as much as possible. jimmyjoy-plennyshake should try too.
If you lower protein it might be a good idea, if possible, to add more fat.