How Does Bariatric Surgery Affect Social Experiences and Well-being - The BaSES-study

Nonrandomized controlled trial to assess whether or not sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) affect social experiences and biomarkers of well-being differently 6 weeks and 1 year after surgery. The decision whether SG or RYGB will be performed is determined by medical decision making.

Hypotheses Bariatric surgery influences social experiences and well-being through changes in body image, reward responsivity and gut hormones .

These changes may differ between gastric bypass (RYGB) and sleeve gastrectomy (SG).

Explanation for choice of comparators

Obesity is one of the world's most serious public health problems. Conservative weight reduction methods alone (diet, exercise) often show disappointing results, as the majority of people who lose weight regain it after a shorter or longer period of time. The currently most effective measure to achieve a durable weight-loss is bariatric surgery.

When investigating the effectiveness of bariatric surgery, the focus has most often been on weight loss and obesity-related complications, while effects on social interaction and subjective experience have received much less attention. A large body of evidence has demonstrated that (supportive) social relationships benefit health. Individuals with low compared to those with high levels of social connectedness are more likely to die prematurely; and social relationships can also affect a range of other health conditions such as cardiovascular disease, cancer, and immune function. Importantly, individuals with obesity may experience social interactions as less positive than normal-weight individuals. They recount avoiding social events and relationships, but also career opportunities, shopping and other activities where they feel observed because of weight stigma. Such avoidance behavior can lead to a "chronic disengagement" with many aspects of social life, which in turn might decrease interpersonal skills. Further investigations into the link between social behavior and eating found that greater emotional eating is associated with greater social avoidance. Eating was described a means to cope with loneliness on the one hand, while on the other hand aggravating feelings of being alone due to the stigma associated with obesity. This way, loneliness and obesity can create a vicious circle. In terms of how bariatric surgery influences social interactions, one 10-year follow up study found improvements in social interactions for bariatric surgery, but not for conventional weight loss treatment. In qualitative studies, many participants mentioned that they received more positive social feedback following bariatric surgery, and that they enjoyed social activities more than before, although they also describe ambiguous feelings.

The present study will investigate whether and how two types of bariatric surgery improve the response to a range of social aspects of patients' daily lives. Further, it aims to determine potential mechanisms leading to these effects, namely changes in body image, gut hormones, and reward responsivity.

Eligibility Criteria:
Inclusion Criteria:

* scheduled for bariatric surgery and eligible for sleeve gastrectomy or gastric bypass
* able to give consent
* understand written and spoken Norwegian

Exclusion Criteria:

* pregnancy and breast-feeding
* chronic disease (endocrine, heart, neurological, lung, gastrointestinal, kidney)
* cancer
* acute psychotic episode