'I don't know which is the chicken and which is the egg': A qualitative study of weight loss-related beliefs and behaviours among adults with psoriasis and comorbid obesity.

OBJECTIVES: Obesity is a common (30%-40%) comorbidity of psoriasis. Weight loss is shown to improve the severity of psoriasis; however, little is known about the factors that may influence successful weight loss in the context of obesity and psoriasis. The current qualitative study aimed to explore the obesity-associated beliefs, perceptions, and behaviours related to weight loss in psoriasis. Preferences for a weight loss intervention were also explored. DESIGN: Qualitative in-depth semi-structured interviews were conducted with 24 adults (62.5% male) with moderate-to-severe psoriasis and obesity (mean body mass index = 35.2 kg/m2 , SD = 4.1), recruited through a patient organization website in the UK. Data were analysed using inductive thematic analysis. RESULTS: Most participants viewed psoriasis as unrelated to obesity. A well-controlled psoriasis and improvements in psoriasis symptoms were considered as major motivators for engaging in a weight loss program by individuals who viewed psoriasis and obesity as related conditions. Comfort eating was perceived as an escape strategy from the psoriasis-induced negative emotions. Participants shared their dissatisfaction with current weight loss recommendations which were too generic. They suggested that a desirable weight loss program would require both emotional and behavioural support, with an emphasis on psoriasis' burden. CONCLUSION: The findings accentuate the importance of (1) clinicians discussing the link between obesity and psoriasis with patients, (2) weight loss advice to include both behavioural and emotional support, and (3) a weight loss advice to consider the psoriasis burden and the perceived barriers which may potentially lead to improved outcomes to obesity management in psoriasis.

The importance of illness severity and multimorbidity in the association between mental health and body weight in psoriasis: Cross-sectional and longitudinal analysis.

Background: High body weight is common in psoriasis and is associated with depression and anxiety. Past studies are mostly cross-sectional and may underestimate the role of demographic and illness-related factors in the association between mental health and body weight in psoriasis. Objectives: This study explored the association between depression and anxiety with waist circumference and body mass index (BMI) cross-sectionally and at 12 months follow-up, adjusting for demographic and illness-related factors in people with psoriasis. Method: Routine psoriasis care data were combined with data on depression and anxiety from a large specialist psoriasis centre. The analytical samples consisted of patients with complete data on either waist circumference (N = 326 at time 1; N = 191 at follow-up) or BMI (N = 399 at time 1; N = 233 at follow-up) and corresponding mental health, demographic, and illness-related information. Associations between weight-related outcomes and mental health variables were assessed at time one and at 12 months follow-up, after adjusting for demographic and illness-related factors. Results: We found no evidence of associations between mental health and waist circumference or BMI, after adjusting for age, gender and illness-related factors. Higher age, male gender and illness-related factors, specifically multimorbidity and psoriasis severity, were positively associated with waist circumference and BMI at both time points. Conclusion: This study revealed the important role of factors related to illness severity in body weight in psoriasis. The contribution of depression and anxiety to weight was not observed here likely due to the sample and methodology used. Future work should explore other psychosocial factors such as weight-related attitudes and emotional eating in the context of weight in psoriasis, to help inform the development of successful weight-management treatments.