Over the past 40–50 years, obesity and overweight have become a growing public health challenge in Norway (1). Bariatric surgery can be a suitable treatment for people with morbid obesity whose attempts at conservative treatment have failed and who have a BMI ≥ 35 kg/m2 with comorbidities or BMI < 40 kg/m2 (2). Gastric bypass is roughly as common as sleeve gastrectomy, and these two procedures accounted for nine out of ten operations in 2021 (3).
Several literature reviews show an increased risk of alcohol use disorders (AUDs) and problematic alcohol consumption following bariatric surgery (4–6). However, these studies are difficult to summarise due to differences in follow-up times, surgical methods and samples (4). A Norwegian registry study of the incidence of post-operative AUDs found that after a gastric bypass and sleeve gastrectomy, 6.36 % and 4.54 % of patients respectively developed AUD per 1000 person-years (7). The risk of developing alcohol dependence after bariatric surgery is higher for gastric bypass, and for men, smokers, those with a pre-operative regular alcohol intake and younger people, as well as with the use of illegal drugs and a lower sense of belonging (4, 8).
Enhancement processes related to the consumption of alcohol change after bariatric surgery and can increase the likelihood of developing AUDs (4, 9). Post-operative anatomical changes intensify and accelerate the effect of alcohol due to the reduced breakdown of alcohol and faster gastric emptying, particularly in the case of gastric bypass (10, 11). A recently published study by Engel et al. (12) with measurements pre-operatively and one year post-operatively identified changes in the rewarding effects and pharmacokinetic effects of alcohol as possible causes of increased risk of AUD after gastric bypass. Enhanced reward reactions to alcohol can occur independently of altered pharmacokinetics, possibly mediated by changes in appetite-regulating peptides in the stomach (11).
Other proposed explanatory models are symptom substitution and addiction transfer, where alcohol triggers the same reward responses in the brain that food did previously (10, 11). Several studies have investigated possible connections between pre-operative food addiction and the development of post-operative AUD. The results show that food addiction among bariatric surgery candidates is relatively common, but the theory of addiction transferral has not been verified (13). In summary, several qualitative studies show increased post-operative sensitivity to alcohol, with faster intoxication, which in turn can lead to less control over alcohol intake (10, 14–16). Other qualitative studies show how problematic alcohol consumption after bariatric surgery is related to unresolved mental health challenges, negative self-image, challenges in dealing with food restrictions, little social support and lack of preparation for the effects of alcohol post-operatively (10, 15). The lifetime prevalence of mental disorders and psychosocial problems among both bariatric and non-bariatric patients with obesity is higher than in the general population (9).
Bariatric surgery involves major lifestyle changes in the form of food restrictions (15) and a change in identity that requires an adjustment to the new post-operative body (17). Following bariatric surgery, where the body is changed, the experience of being accepted in public can also change (18). One hypothesis is that increased social participation can mean easier access to alcohol for some patients, which in turn can boost consumption (9).
Few studies have focused on patients' own experiences with developing alcohol problems. As far as we know, no studies have been conducted in a Norwegian context. In this study, we wanted to examine how post-bariatric patients receiving interdisciplinary specialised treatment for substance use disorders (referred to here as SUD treatment) describe their experiences with developing alcohol problems. We wanted to explore this based on a biopsychosocial understanding of the phenomenon (19, p. 120), starting from a critical realist scientific position, where the complexity of the phenomenon and the interplay between biological, psychological and social mechanisms are highlighted (20).
The following research question was formulated: What are the experiences of post-bariatric patients who received a referral for SUD treatment for alcohol consumption pre- and post-operatively, and why do they think that their alcohol consumption became problematic?