*Geek Box: Open Label Trials & Within-Person Comparisons
‘Open label’ means that both the researchers and the participants know what intervention the participants are receiving. Consequently, it is completely unblinded, compared to a single-blind trial, where the researchers know what intervention the participants are receiving, or a double-blind trial, where neither researchers or participants know. Open-label trials are often used to compare treatments, or interventions.
For example, comparing Drug A vs. Drug B, or comparing Diet A vs. Diet B. While blinding is desirable as a means to reduce bias being introduced into a study, it is not always feasible, particularly in nutrition research where participants are being asked to comply with a specific intervention. In the present study, the researchers wanted to compare the effects of consuming breakfast to skipping breakfast and fasting until lunch. It would have be unfeasible, given the testing protocols involved, to blind researchers and participants to this; hence the trial was conducted as an open-label study, with participants randomised to either the breakfast or breakfast skipping group first, before crossing over to the opposite of which intervention they started with.
‘Within-subject’ means that each subject was compared against themselves; their data from one intervention compared to the other. It means the results are less influenced by differences from person to person.