Effect of Non-Deceptive Placebo on Weight Loss: An Exploratory Study

Abstract

Background: The continued high prevalence of obesity calls for novel treatments or treatment adjuncts. Open-label placebos (OLPs) can improve medical conditions despite that patients know they are receiving a placebo. OLP has not been tested in obesity.

Aim: To explore if OLP augments weight loss.

Methods: N=31 adults, mean BMI 34.9, were assigned to an OLP or no-OLP group during a weight-loss intervention. Body weight, compliance, suggestibility, and perceived importance of theorized factors on weight change were assessed with questionnaires.

Results: OLP failed to augment weight loss. Only 45% of the OLP group took the pills as instructed, consistent with report of little-to-no belief that they affected body weight.

Conclusions: Results question if OLP benefits generalize to conditions requiring action from patients and to studies with objective outcome measures. In either case, it is clear that the potential of OLPs to enhance obesity treatments hinges foremost on increasing belief in them.