In a meta-analysis (looking across multiple studies), the results showed that adding hypnosis increased weight loss by an average of 97 per cent during treatment. In studies of hypnosis versus no hypnosis the average short term weight loss was 6lb for those not using hypnosis and 11.83lb with hypnosis, Moreover, effectiveness increased post treatment by over 146 per cent, with the average weight loss without hypnosis remaining at 6lb, but with hypnosis it jumping to 14.88lb. Thus demonstrating that weight loss hypnosis therapy works even better over time. (Kirsch, Irving (1996).Hypnotic enhancement of cognitive-behavioral weight loss treatments-Another meta-reanalysis. Journal of Consulting and Clinical Psychology, 64 (3), 517-519).
109 17-67 year olds completed a behavioural treatment for weight management either with or without the addition of hypnosis. Results show that, at the end of the 9-week program, both interventions resulted in significant weight reduction. However, at 8-month and 2-year follow-ups, the hypnosis subjects showed significant additional weight loss, while those in the behavioural-treatment-only group exhibited little further change. Hypnosis clients showed significant additional weight loss and were more likely to have achieved and maintained their personal weight goals. (Bolocofsky, David N.; Spinler, Dwayne; Coulthard-Morris, Linda (1985). Effectiveness of hypnosis as an adjunct to behavioral weight management. Journal of Clinical Psychology, Volume 41 (1), 35-41)