During the pre-operative assessment process, it is important to assess the patient's knowledge of, and expectations for bariatric surgery to determine if they are realistic, provide education about the typical outcomes following surgery, and discuss the post-operative dietary guidelines that the patient will need to adhere to for an optimal outcome.

Bariatric surgery is not a magic bullet. Although it is currently the most effective treatment for severe obesity, long-term changes to dietary intake and physical activity are required to maintain significant weight loss. Difficulties making and sustaining these lifestyle changes account for some of the variability in weight loss outcomes that are observed following bariatric surgery. Although bariatric patients typically lose 20% to 30% of their total body weight and experience significant improvements in their physical and mental quality of life, a subset of patients does not achieve the expected weight loss and/or they experience significant weight regain (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3955952/).

Most weight loss occurs within the first year following surgery, and motivation may dwindle as the weight loss begins to plateau. It's important to acknowledge that food (particularly hyperpalatable ultra-processed food) is highly rewarding and serves important functions for many people, such as regulating negative emotions, providing a sense of comfort, or distracting from boredom. Surgery alone does not directly address some of the factors contributing to weight gain, such as emotional eating. It is recommended that patients are assessed for psychosocial factors that may contribute to weight regain (e.g., emotional eating, binge eating, depression) during the post-operative period and offered psychosocial interventions such as motivational interviewing (MI) and cognitive behavioural therapy (CBT) before significant weight regain occurs (David, Sijercic, & Cassin, 2020).

Our research has shown that motivational interviewing can improve readiness and confidence for change, binge eating, and some measures of dietary adherence among post-operative bariatric surgery patients who were having difficulty adhering to the post-operative dietary guidelines (David, Sockalingam, Wnuk, & Cassin, 2016), and CBT can improve disordered eating and psychological distress (e.g., depression, anxiety) among pre- and post-operative bariatric patients (Cassin, Sockalingam, Du, Wnuk, Hawa, & Parikh, 2016; Sockalingam, Leung, Hawa, Wnuk, Parikh, Jackson, & Cassin, 2019).

The prevalence of food addiction is higher in pre-operative bariatric patients than in post-operative bariatric patients, and food addiction symptoms do tend to improve following bariatric surgery for many individuals. Our research suggests that those who continue to experience food addiction following surgery have greater severity of food addiction symptoms and experience greater binge eating and psychological distress in comparison to bariatric patients who do not experience food addiction following surgery (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7598202/). Our preliminary research suggests that CBT delivered following bariatric surgery can help to improve the severity of food addiction symptoms immediately following the intervention.

Body image tends to improve following bariatric surgery; however, post-operative bariatric patients still report more negative body image on average in comparison to the general population. Some patients experience "phantom fat" or "mind-body lag," a phenomenon where they perceive their bodies to be larger than they are because it takes a while for the mind to adjust to the physical changes that occur in response to rapid weight loss. See our chapter on body image (Cassin & Friedman, 2017) in Psychiatric Care for Severe Obesity (https://www.amazon.ca/Psychiatric-Care-Severe-Obesity-Interdisciplinary/dp/331942534X).

It can be challenging to assess body image following bariatric surgery. In comparison to their pre-surgery bodies, bariatric patients may feel satisfied with their weight loss and improved physical functioning while also feeling dissatisfied with the excess skin that develops as they lose weight. Most patients who undergo bariatric surgery experience excess skin to varying degrees as a result of drastic weight loss. Some patients may choose to undergo body contouring surgery to remove excess skin, particularly if it impairs their physical functioning (e.g., makes it difficult to exercise). Body contouring surgery has been shown to improve physical functioning and psychological wellbeing following bariatric surgery (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6153583/). Cognitive behavioural therapy may improve body image by shifting the focus from body appearance to body functionality (i.e., from what the body looks like to what it is capable of doing) and helping the patient confront situations they had been avoiding as a result of poor body image.

Some patients experience worsening of a pre-existing alcohol use disorder following bariatric surgery, whereas others without a history of problematic alcohol use may experience a new onset of alcohol use disorder (See attached Parikh et al., 2016). One reason this may occur is that bariatric patients may have been using food to cope with negative emotions, and they may turn to other substances or addictive behaviours if they are unable to cope using food following surgery.

Bariatric candidates may be motivated to underreport their alcohol use during the pre-operative assessment process for fear that surgery will be denied or significantly delayed. It is important to discuss the rationale for screening for alcohol use (as well as other issues that may impact bariatric outcomes) and to communicate that the goal of the assessment is to ensure that it is an optimal time for the patient to undergo bariatric surgery and that supports are in place to increase the likelihood of a successful outcome.

Regular alcohol consumption increases caloric intake without any nutritional benefits and can lead to nutritional deficiencies. Gastric bypass surgery (a common type of bariatric surgery) is associated with accelerated alcohol absorption, higher maximum alcohol concentration, and longer time to eliminate alcohol (Parikh et al., 2016). There is an increased risk of developing alcohol use disorder and experiencing adverse effects of alcohol consumption (e.g., driving under the influence) following gastric bypass.

Motivational interviewing and cognitive behavioural therapy are both effective in the treatment of alcohol use disorder. Motivational interviewing can be used to examine ambivalence about reducing alcohol consumption and increase self-efficacy in one's ability to reduce their drinking. Cognitive behavioural therapy can be used to teach a variety of coping strategies that may be used to manage negative emotions without relying on alcohol and to cope with urges to drink.

Cognitive behavioural therapy is an evidence-based treatment that focuses on the development of coping skills. The basic premise is that thoughts, emotions, and behaviours are all interconnected, and the way an individual thinks about or appraises an event impacts their emotions and their behaviours. For example, a person who thinks "I’ll never be able to lose weight” may feel hopeless in response. Feelings of hopelessness do not motivate behaviour change. Instead, hopelessness may increase vulnerability for weight promoting behaviours, such as emotional eating and sedentary behaviour. These behaviours, in turn, provide some evidence to support the thought, “I’ll never be able to lose weight.” The goal of CBT is to replace maladaptive thoughts and behaviours with more adaptive ones.

Some components of effective CBT interventions for bariatric patients include education about the relationship between thoughts/emotions/behaviours and the regulation of body weight, goal setting, meal planning, recording food consumption and physical activity, tracking weight, problem-solving, challenging negative thoughts, and relapse prevention (Cassin, Sockalingam, Du, Wnuk, Hawa, & Parikh, 2016; Sockalingam, Leung, Hawa, Wnuk, Parikh, Jackson, & Cassin, 2019).

CBT is an “action-oriented” treatment, which assumes that people are ready to make changes. However, people often feel ambivalent about making changes for a variety of reasons. For example, their current maladaptive behaviours may serve important functions (e.g., using food to cope with negative emotions or to reward oneself), or they may feel skeptical that change is possible due to low self-efficacy given previous unsuccessful attempts at making lifestyle changes. Motivational interviewing can be used prior to CBT to explore ambivalence about change, bolster self-efficacy, and increase intrinsic motivation for change by having the patient vocalize the reasons for change, so their behaviour aligns with their values. When the patient feels ready to take action, CBT strategies can then be introduced to help the patient make lifestyle changes. Our book, Psychological Care in Severe Obesity (https://www.amazon.ca/Psychological-Care-Severe-Obesity-Integrated/dp/1108404049), includes several chapters on using MI and CBT to help patients make lifestyle changes and improve disordered eating.

Cognitive behavioural therapy focused on the treatment of obesity typically results in a total weight loss of 5% to 10%. In addition to weight loss, CBT has also been shown to improve disordered eating and psychological distress among individuals with obesity and among bariatric surgery patients specifically (Cassin, Sockalingam, Du, Wnuk, Hawa, & Parikh, 2016; Sockalingam, Leung, Hawa, Wnuk, Parikh, Jackson, & Cassin, 2019). We conducted a review of psychosocial interventions for bariatric surgery patients and found that cognitive and behavioural interventions had the strongest support for improving disordered eating (e.g., binge eating, emotional eating) and psychological functioning (e.g., depression, anxiety, quality of life) (David, Sijercic, & Cassin, 2020).

Bariatric surgery patients report very high rates of childhood maltreatment, including emotional, physical, and sexual abuse (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6481306/; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2893145/). Some patients experience post-traumatic stress disorder (PTSD) as a result of these experiences. It is important to assess for trauma during the pre-operative assessment because patients may require additional support while they are going through the surgery process. If their symptoms are severe or unstable, a trauma-focused CBT intervention, such as Cognitive Processing Therapy, may be warranted to improve PTSD symptoms before proceeding with surgery. Post-operative follow-up is recommended because some patients may experience a re-emergence or worsening of PTSD symptoms. Some people who have experienced trauma turn to food to cope with negative emotions and may have difficulty regulating their emotions following bariatric surgery. In addition, some people with a history of sexual trauma report that the weight loss process can feel scary because they felt somewhat protected while living in a larger body and feel more vulnerable as their body becomes smaller and they receive more attention and comments about their body.