Hey, just some input on research methods and possible research avenues for rob and other DIYers.
First, something to keep in mind throughout the research process: dietary science is largely economically driven. many fundamental beliefs in the field are untested, and/or do not reflect actual research. Example: pretty much anything that comes out of Dr. Oz’s mouth. A particularly good example is the resveratol craze, which was caused by a study that showed a slight improvement in mice when fed a diet that included something like half their body weight in resveratol. So read the journal articles yourself instead of referring to conventional sources of information.
First area of research: macro nutrients. USDA reccomendations on macronutrient ratios are not based on thorough research, and are highly disputed. it is probably a good idea to do at least a single blind test of different ratios. make several mixes with different ratios of fat/carbs/protein, cover the labels, shuffle the tubs and then label by number. try each for a week or two and then take the cover off the winner to see what mix it was.
Second, electrolytes, minerals, and pH balance. electrolytes affect each other in complex ways. For example, a lower pH caused by other electrolytes and macronutrient intake will cause your body to use more calcium to raise the pH again. If you don’t have enough calcium in your diet, it will get the calcium from your bones. another example is simple electrolytes like sodium and calcium. more of one will make your body excrete more of both. Adding more K might actually lower your Na. so much like macro nutrients, the ratio here is actually more important that the total intake - keep this in mind while experimenting with these things.
Finally a word of encouragement. While the body is a very complex system, it’s also very resilient. While I’m sure soylent has some ways to go before it is perfected, it’s already way healthier than the standard american hot pockets and mountain dew diet. So if college students aren’t dropping dead from nutritional deficiency, soylent users should be totally fine. So please disregard nutritionist fearmongering. Good luck!