Anne Christenson

Background: Having obesity already at young age is associated with increased risk for cancer, fatty liver disease, cardiovascular disease, diabetes type 2, and premature mortality. Obesity in youth is also associated with negative psychosocial and economic consequences in later adulthood. Between 1980 and 2020, the proportion of young adults (16-25 years) in Sweden with a body mass index (BMI) >30 rose from 0.5% to 3.1% in girls and from 1.4% to 10.1% in boys. There is a large knowledge gap for the age group 16-25 years, regarding long-term effects of medical or surgical obesity interventions. Previous studies focused on children, on younger teenagers (13-17 years) or on adults >25 years. It is therefore important to study the treatment effects on young adults with obesity and how they may be better supported to optimize short- and long-term weight and health outcomes, both with and without bariatric surgery. Methods The Center for Obesity in Stockholm provides specialist medical obesity treatment, supporting patients >16 years in improving their diet and exercise habits. The clinic also offers a pre- and post-surgery program for 16-25-year-old patients who undergo obesity surgery (for weight loss). Epidemiological studies The applicant set up the prospective cohort Swedish Youth with Obesity (SYO) in 2018, to study the health status and weight development in young adults admitted for obesity treatment. The cohort offers a unique opportunity for epidemiological studies on a seldom studied population, and so far the cohort have recruited over 800 participants which is, to our knowledge, the largest cohort of youth with obesity in the world. Participants provide data from blood tests, questionnaires and anthropometric measurements. Data is collected at enrollment, after 18 months and after 3, 4 and 5 years. With a research grant we will perform epidemiological analyses using the already collected, but unpublished, data from the SYO-cohort and answer research questions such as how weight, blood sugar levels or eating patterns are distributed between subgroups of participants, as well as how they change over time after medical and surgical interventions. Qualitative study The grant will also finance a qualitative interview study to follow up how participants perceive their treatment and health and how they think the treatment could be improved. We will recruit participants for individual interviews and focus groups from the Center for Obesity after ethical approval have been obtained. With purposeful selection we will recruit participants with varied backgrounds regarding gender, age, BMI, country of origin, and type of treatment (medical or surgical). The experiences, opinions and wishes from young participants will guide future treatment improvements. Associated professor Stephanie Bonn (KI) will assist the applicant with statistical calculations in the epidemiological studies, and she will also co-perform the qualitative analyses for research triangulation. Ethical considerations People with obesity is a patient group who suffer from weight stigma and discrimination in society as well as within health care. The shame surrounding the disease contributes to a reluctance among patients to seek treatment and they are often hard to recruit to studies. Hence, it is important to gather more information from a population whose voices are seldom heard, about how we may best support this patient group to achieve better health. Ethical approval has allready been obtained for the epidemiological studies. For the qualitative study ethical approval will be applied for.