A wide range of health issues, including quite severe mental health problems, was prevalent in treatment-seeking young adults with severe obesity. These are likely to constitute a major treatment challenge, including options relating to bariatric surgery.

Mean body mass index was 39.2 kg/m 2 (SD = 5.2). We found evidence of poor mental health, including present psychiatric diagnoses (29%), symptomatology of anxiety (47%), depression (27%) and attention-deficit/hyperactivity disorder (37%); low self-esteem (42%), attempted suicide (12%), and low quality of life (physical component score = 46, SD = 11.2; mental component score = 36, SD = 13.9, P<0.001 for difference). Variables independently associated with present anxiety symptomatology (R 2 = 0.33, P<0.001) included low self-esteem (P<0.001) and pain (P = 0.003), whereas present depressive symptomatology (R 2 = 0.38, P<0.001) was independently associated with low self-esteem (P<0.001), low cardiorespiratory fitness (P = 0.009) and obesity-related problems (P = 0.018). The prevalence of type 2 diabetes was 3%, and hypertension 2%. Insulin resistance was present in 82%, lipid abnormality in 62%, and poor cardiorespiratory fitness in 92%. Forty-eight percent had at least one micronutritional deficiency, vitamin D being the most common (35%).

Data collection at admission of present and life-time health issues including symptomatology of anxiety, depression (Hospital Anxiety and Depression Scale) and attention-deficit/hyperactivity disorder (Adult ADHD Self-Report scale); self-esteem (Rosenberg Self-Esteem Scale), suicide attempts, health-related quality of life (Short Form-36 Health Survey), psychosocial functioning related to obesity (Obesity-related Problems Scale), cardiorespiratory fitness (Astrand´s bicycle ergometer test), somatic and psychiatric co-morbidities, cardiometabolic risk factors, and micronutritional status. We used multiple regression analysis to identify variables independently associated with present anxiety and depressive symptomatology.

Copyright: © 2015 Dreber et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Our primary aim was to comprehensively characterize treatment-seeking young adults (16–25 years) with severe obesity, with a specific focus on mental health in order to provide the practitioner with clinical data on an understudied but vulnerable patient category. We also aimed to clarify factors associated with present anxiety and depressive symptomatology in young adults with obesity, independently of body mass index.

Previous clinical characterizations of young adults with obesity have mainly focused on physical health and/or included only pre-bariatric surgery patients or a limited number of participants [ 17 – 19 ], showing higher prevalence rates of cardiometabolic risk factors and psychiatric diagnoses compared to the general population.

Despite the importance of young adults in the obesity epidemic, this population has been overlooked in clinical obesity research [ 9 ], resulting in limited knowledge for clinicians.

Evidence suggests that young adulthood is a vulnerable period for weight gain [ 8 , 9 ], possibly due to young adults´ susceptibility to food marketing as well as to social influences on meal patterns [ 9 , 10 ]. Lifestyle change programs for young adults have proven challenging [ 11 ] while bariatric surgery may result in favorable short-term weight reductions [ 12 ]. However, mental health challenges post-bariatric surgery, such as alcoholism and suicide [ 13 – 15 ], cause concerns especially for young adults since the incidence of psychiatric disorders peak at 24–27 years of age [ 16 ].

Young adulthood is not defined by chronological age but is characterized sociologically by a transformation to independence, identity building and establishment of behaviors that last into adulthood [ 6 ]; and neurologically by a reward-seeking and risk-taking behavior [ 7 ].

Obesity (body mass index ≥30 kg/m 2 ) is a global health threat associated with reduced life expectancy and quality of life [ 1 , 2 ]. In developed countries, the most rapid weight gain occurs in young adulthood with prevalence rates of 8.3% in women and 8.9% in men for 15–19 year-olds, and 13.2% in women and 12.2% in men for 20–24 year-olds (extracted data) [ 3 ]. Obesity among young adults is associated with negative metabolic, social and economical consequences in later adulthood [ 4 , 5 ].

Method

Subjects and recruitment This cross-sectional study was conducted at the multidisciplinary young adult section of the Obesity Center at Karolinska University Hospital, serving all municipalities of Stockholm. Patients are referred from outside medical specialists, dietitians or school nurses. Referral requirements to the young adult section of the obesity center are age 16–25 years (definition of young adulthood by Stockholm health care), body mass index (BMI) ≥35 kg/m2 or BMI ≥30 kg/m2 with obesity-related co-morbidities (somatic or psychiatric). Patients with known eating disorders according to DSM-IV criteria [20], are referred directly to eating disorder specialist clinics for treatment prior to programme initiation at the Obesity Center. Treatment options at the Obesity Center include behavioral management programme or pre-bariatric surgery care. Patients referred to the young adult section of the Obesity Center, were invited to participate in the study following oral information at their first visit to the clinic. Exclusion criteria: patients in need of a language interpreter or with known diagnosis of an intellectual disability, i.e. patients who were not able to fill in questionnaires independently. Eighty-seven percent (n = 236) out of 270 patients accepted for clinic enrollment met the study inclusion criteria. Seventy percent (n = 165) of eligible patients chose to participate, and provided written and oral consent. For participants <18y, parents’ written consent was obtained. At the first visit to the Obesity Center, participants were given a self-administered questionnaire to fill in at home, were referred for blood chemistry testing and invited to an enrolment day. On the enrolment day (second visit) the participants were interviewed and examined by a team of obesity professionals. Data from questionnaires, blood tests and clinical interviews/examinations were checked by a physician. In total, the participants visited the Obesity Center twice as part of the study. The study, including consent providal, was approved by the Stockholm Regional Ethical Review Board (2012/1154-31/4). All data were collected September 2012 –November 2014.

Clinical data collection Anthropometry in light clothing and without shoes was assessed by a trained nurse. Body weight was measured to the nearest 0.1 kg using a digital calibrated scale. Height was measured to the nearest 0.5 cm using a wall-mounted stadiometer. BMI was calculated as weight/height2 [21]. For participants <18y, class I obesity was calculated according to the definition by Cole et al [22], and class II obesity was calculated according to Kelly et al [23]. Class III obesity was defined as BMI ≥40 kg/m2. For participants 18–25 years old, standard World Health Organization BMI categories were used [24]. Waist circumference was measured to the nearest 0.5 cm at the mid-point between the lower margin of the lowest rib and the top of the iliac crest. Blood pressure was assessed once after five minutes rest in sitting position using a manual instrument (Boso manometer, Henry Eriksson AB, Stockholm/Jungingen). Cardiorespiratory fitness was measured by Astrand´s submaximal bicycle ergometer test for the prediction of VO 2 max [25]. The results (ml VO 2 /kg*min) were classified as either very poor, poor, average or fair; taking gender and age into account in the calculation [25]. A semi-structured interview covering present and life-time incidence of obesity-related comorbidities, medications and treatments; and psychosocial problems was conducted by a physician. Co-morbidities were reported if present in the referral notes or the patient health record (coded according to International Statistical Classification of Diseases and Related Health Problems–Tenth Revision–SE [26]). Medications were classified according to the Anatomic Therapeutic Chemical classification system [27]. Adverse childhood experiences were classified independently by three physicians into no adverse event, absent parent (physical), family history of substance abuse, act of omission (failure to provide for a child´s basic needs) and/or act of commission (words or overt actions that cause harm) [28]. Identical classification by all three doctors was interpreted as a case.

Questionnaires/self-assessment The form consisted of widely used questionnaires and single questions. Upon completion, the questionnaire was checked twice together with the participant, firstly by a nurse and secondly by a physician. The main assessment of mental health problems was symptoms of anxiety and depression, which were examined by using the Hospital Anxiety and Depression Scale (HADS) [29]. HADS is a validated 14-item likert scale used for detection of both anxiety and depression in adults and adolescents [30]. Items are scored 0–3 points and summarized into a continuous variable or categories as follows: no impairment (≤7 points), subclinical (8–10) or clinical impairment (≥11 points) [29]. The Rosenberg Self-Esteem scale [31] was used to detect low self-esteem. The scale includes 10 items, with a four-point likert scale (0–3 points) for scoring, and has been validated in young adults [31, 32]. Low self-esteem was defined as ≤15 points according to the most commonly used cut-off value. Psychosocial functioning related to obesity was evaluated by using Obesity-related Problems Scale (ver. 1.2), which has been validated in ≥18y and used in ≥13y [33, 34]. The questionnaire comprises eight questions on a four-point likert scale and measures the degree to which participants currently experience obesity-related botherings during daily activities, such as when swimming or socializing. The scores were summarized and transformed into a score of 0–100. A score of <40 points indicates mild, 40–59 points moderate, and ≥60 points severe impairment in obesity-related psychosocial functioning [33]. Health-related quality of life was assessed using the Short Form-36 Health Survey (version 1.0) (SF-36) [35], which has been validated in Swedish 15–93 year-olds [36]. SF-36 is composed of 36 questions about functional health in the last four weeks and the responses are transformed into eight domains and two summary measures (a mental and a physical component score), each ranging from 0 to 100. A score of 100% equals optimal health. The non-norm based scoring system was used in the present study. Part A of the Adult ADHD Self-Report Scale [37] was used to assess concentration and hyperactivity associated with attention-deficit/hyperactivity disorder (ADHD). The scale was constructed for ≥16y and has been validated in ≥18y [38]. Responses are summarized into a score of 0–6 points. Four points or more is associated with ADHD disease. Suicide attempt was assessed by a question that had been used and tested in the Swedish National Health Survey [39]: “Have you ever tried to commit suicide”, with the response options of “never”, “yes, more than one year ago”, “yes, past year” or “yes, past week”. Sleep impairment was assessed by the Karolinska Sleep Questionnaire [40]. The questionnaire is validated in ≥18y and consists of 18 items that are calculated into four subscales of a mean score of 0–5 points: sleep quality, non-restorative sleep, sleep apnea and sleepiness. High values indicate more impairment in the last three months [40]. Prevalence of insomnia was calculated by combining items which correspond to the DSM-IV-criteria [41]. Separate questions were included to assess economic strain, nationality, occupation, pain as measured by EuroQol 5-dimensions (reported as mild or severe) [42], daily tobacco use, alcohol and cannabis use, sexuality, social support, and skin type as measured by Fitzpatrick scale [43]. Apart from the latter, the separate questions followed the same outline as in the Swedish National Health survey [39]. See table in S1 Table for further descriptions.

Metabolic risk factors and nutritional status Blood samples of metabolic risk factors and micronutritional status were obtained by venous puncture after overnight fasting. See table in S2 Table for specification of the included blood samples and threshold values. Insulin resistance was calculated by using the homeostasis model assessment (HOMA-index) [44].