The 'gold standard' in nutritional and medical studies is the random controlled trial (RTC) which relies on the fact that neither the experimenters nor the subjects are aware of which subjects are getting the actual intervention or are receiving a placebo (an inert preparation that is indistinguishable from the real substance being tested, be it a pill, an injection, etc.). The idea is that this will control for the bias of both the experimenters and the subjects so that their preconceived...