A scientific experiment that changes one thing at a time is all but useless when it comes to trying to improve human health. The misleading conclusions can be downright harmful to our health. Our clinical trials are prime examples of this – useless and harmful- and terrible wastes of money! I simply would not fund any univariate experiments.
We have to use common sense, realize how incredibly multivariate biological phenomena are, and do shotgun experiments. After a successful multivariate intervention, that is, a shotgun experiment, we can reverse one thing at a time to gauge how big the individual effects are. But only after a successful intervention!