**4. Discussion**

The present study is, to our knowledge, one of the first to investigate the influence of obesity surgery on psychological burden in patients with obesity. We analyzed possible effects of obesity surgery during the COVID-19 pandemic on mental health burden (PHQ-8, GAD-7, COVID-19-related fear, DCSEB) by comparing patients *with* and *without* obesity surgery. In general, group comparisons showed no differences between these groups, suggesting that the surgery did not affect any psychological state. The two groups only differ at a trend level in generalized anxiety and depressive symptoms, suggesting a slightly increased burden in individuals without surgery. More precisely, in individuals that do not suffer (much) from generalized anxiety, DCSEB does not differ across obesity surgery groups (*with* or *without*). In contrast, people that do suffer from generalized anxiety differ in their DCSEB depending on their obesity surgery status (*with* or *without*), with more DCSEB in people with a surgery. Accordingly, generalized anxiety moderates DCSEB after obesity surgery. The interaction between generalized anxiety and history of obesity surgery shows

that people with obesity already suffering from generalized anxiety symptoms and/or bulimic eating seem to suffer even more compared to people who already underwent the surgery during the pandemic. Thus, generalized anxiety seems to be a risk factor for dysfunctional eating behavior after obesity surgery during the COVID-19 pandemic.

The COVID-19 pandemic still has a deep impact on our social life, quality of life, and mental health [18,36]. COVID-19-related fear and generalized anxiety, particularly for vulnerable individuals, play decisive roles in mental health during the pandemic [17,32,37,38].

Meanwhile, anxiety is linked to all types of eating disorders [39,40] and is the most prevalent emotion obese people with a binge eating disorder experience prior to a binge [41]. The frequency of binge eating episodes is higher in patients with higher anxiety scores than in grade III obesity patients [42–44]. Thus, negative emotions seem to be controlled and regulated by activating the neuronal reward system during the consumption of palatable foods [45,46].

In times of increased mental distress caused by the COVID-19 pandemic, the access to protective resources could be difficult so that people may fall back into old behaviors using the same emotion regulation strategies as before the pandemic. This means that, on one hand, obesity surgery does not offer an increased stress resilience during the COVID-19 pandemic and, on the other hand, mentally stable people who underwent obesity surgery will continue to do so even in times of crisis. For those who already suffer from mental illnesses or instability, mental decompensation can occur more quickly in times of mental distress because of the COVID-19 pandemic. Thus, psychosocial evaluation and support is of particular importance for obesity patients prior to surgery in order to avoid possible dysfunctional stress regulation, consecutive weight gain, and eventually the deterioration of long-term results [47,48]. Before the pandemic, studies showed that in most patients, mental health improved after obesity surgery even in patients with previous psychiatric illnesses. However, underlying mechanisms and psychological factors remain unclear [24,25,49]. Individual psychological resources seem to be one important protective factor for mental health in people suffering from obesity [50].

These results once again underline the need and importance for structured interdisciplinary aftercare in the group of obesity surgical patients suffering from psychological distress during the COVID-19 pandemic, including psychotherapeutic and psychosocial support. Low-threshold support services are required, such as evidence-based cognitive behavioral emotion regulation skills like stress management, meditation, physical exercise, stimulus control, etc. These could increase the likelihood that mental illnesses will turn chronic [51]. Emerging E-mental health interventions could be a helpful tool and an addition to support people with psychological burden [52]. Special consideration should be given to find tailor-made interventions and aftercare support towards patients who continue to show compensatory eating behavior postoperatively in the context of psychological distress.
