[_xiaz]

Not really.

You could create several cohort with different co-controlled fixes for each: more calories, more protein, more fiber, more nutrients.

Then evaluate the percentage of successfully treated patients in each cohort.

It's of course a difficult study, since someone with a bad diet will lack practically everything, so more things will work than not. I'd also be curious to see how you would design a real food diet high in micronutrients without accidentally adding a bunch of fiber in the process