Randomised Controlled Trial (RCT) is a type of scientific experiment which aims to reduce bias when testing a new treatment. The people participating in the trial are randomly allocated to either the group receiving the treatment under investigation or to a group receiving standard treatment (or placebo treatment) as the control. By use of a control or placebo group, it is possible to specifically measure the effect of such an intervention and, “cause and effect” can be established.
In a double blinded RCT the treated individuals and the researchers do not have knowledge of which treatment they are undertaking respectively observing. In the area of nutrition, few studies are double-blinded RCT’s as it is obvious when a change to the diet is made. Nevertheless there are some very high quality nutrition-related RCTs in the literature.