The big thing that sticks out here, and makes all the science hard to prove or disprove, is that no-one actually sticks to the diet they are assigned in a trial

The big thing that sticks out here, and makes all the science hard to prove or disprove, is that no-one actually sticks to the diet they are assigned in a trial! Almost everyone agrees that you shouldn't eat the processed crap - but after that, the results become harder to get out of trials.