Effects of open-label placebos on weight loss and feelings of hunger in obesity

• Applicant: Professor Dr. Michael Schaefer, Ph.D.
• Subject Area: Nutritional Sciences
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 543087150

In the last decades overweight and obesity have become one of the leading public health problems in populations worldwide, associated with morbidity and mortality as well as an economic burden. Different approaches to reduce weight are discussed, including dieting, drug interventions, and surgery. Moreover, it has been demonstrated that a placebo treatment may have an impact on weight loss or feelings of hunger when trying to reduce weight. Since placebos are given in a concealed way, ethical concerns with respect to the patient–healthcare provider relationship are known. However, intriguing recent studies show that placebos can be effective even when one knows that a placebo is being administered (open-label placebos). This has been demonstrated, for example, in depression, chronic pain, anxiety, and stress. In a recent pilot study with 71 participants we have demonstrated that open-label placebos successfully reduced hunger and increased perceived social support in non-obese participants who wanted to lose weight. The present proposal ties in there and aims to examine the impact of open-label placebos in obese individuals. We will examine whether an open-label placebo will help to reduce weight and hunger feelings compared with a control group. Moreover, we want to compare the effects of open-label with those of conventionally concealed placebos and examine the role of expectation and belief in open-label placebos. Finally, we will observe how long-lasting the changes are. The results of this first study on effects of open-label placebos in obesity will contribute to our understanding of placebo effects and represent another step toward possible new ways to help obese patients, an ever-growing group and one of the greatest challenges for our health system.

• DFG Programme: Research Grants