Diet, gym, supplements, or maybe it is all in your mind? A systematic review and meta-analysis of studies on placebo and nocebo effects in weight loss in adults.

The findings suggest a possibility that the nocebo effect may occur when an intervention has a medical context. In contrast, the placebo effect can be observed in cases where the intervention is of a different nature. However, considering the low number of studies analyzing the use of placebos in weight loss, new primary research is needed.