Long-term randomized controlled clinical trials for diet interventions are extraordinarily expensive, often last only a few weeks, and are difficult to control due to numerous confounders.

“um and I haven't seen one that tracked you know an entire diet for more than six months most of them are just a few weeks at most this is in in people um so I mean all these other studies you know they tried to change one thing like the like the you know the ones you'd mentioned La American veterans trial the Minnesota coronary survey and the you know they tried to change one thing about the diet but you know you've got all a million confounders really in all those too”