Obesity and body-image concerns in adolescents — formative SAQs

SAQ 1 — Classification, screening and assessment (10 marks)

A 15-year-old girl is referred because her BMI plots above the 97th percentile. She has acanthosis nigricans and irregular periods. Her mother, who has type 2 diabetes, is anxious and asks whether her daughter is "obese and diabetic." In private, the girl discloses she has been skipping meals to lose weight and feels "disgusting." [1] [8]

Questions

1. Classify her weight status using the correct BMI-for-age definitions, and state the severe-obesity threshold. (3 marks) [1] [7]
2. Outline the baseline comorbidity investigations you would order and why. (4 marks) [1] [2]
3. Describe how you would assess her body-image concern and eating behaviour, including the specific screening tools and the urgency of her restrictive eating. (3 marks) [10] [8]

Model answer

Classification (3). Obesity is defined as a BMI at or above the 95th percentile for age and sex on a CDC or WHO growth reference; this girl plots above the 97th percentile, so she meets obesity. Severe obesity is defined as a BMI at least 120 percent of the 95th percentile, or an absolute BMI of at least 35. I would calculate her percentage of the 95th percentile to determine whether she has crossed into severe obesity, because that threshold triggers escalation beyond lifestyle. At 18 years the classification switches to adult cut-offs (overweight at least 25, obesity at least 30). I would use person-first, weight-neutral language with the family rather than the word "obese" directed at the patient. [1] [7]

Baseline comorbidity investigations (4). Fasting glucose or HbA1c to screen for pre-diabetes or type 2 diabetes, given her family history and acanthosis nigricans. A fasting lipid panel for dyslipidaemia. ALT to screen for non-alcoholic fatty liver disease, with the understanding that ultrasound is insensitive for early steatosis. Blood pressure with an appropriately sized cuff. Given her irregular periods and acanthosis nigricans, I would also consider the overlap with polycystic ovary syndrome and check for biochemical hyperandrogenism. An oral glucose tolerance test is added if fasting glucose is in the pre-diabetes range. [1] [2]

Body-image and eating-behaviour assessment (3). I would use the HEeadsss framework to place her weight inside her whole life. I would administer the EAT-26 (or ChEAT) and the SCOFF questionnaire to screen for disordered eating, and the PHQ-A for depression. Her disclosure of skipping meals to lose weight, alongside body-image distress, raises concern for restrictive eating that could constitute atypical anorexia if it is producing physiological instability. I would therefore assess for bradycardia, orthostatic vital-sign changes, and weight-loss tempo, and escalate to an eating-disorder pathway if there is any instability, because atypical anorexia carries the same medical danger as classic anorexia despite a higher weight. Weight-loss management is held until eating-disorder stability is established. [10] [8] [15]

SAQ 2 — Staged management and weight-neutral care (10 marks)

A 16-year-old boy has a BMI at 130 percent of the 95th percentile, newly diagnosed impaired glucose tolerance, and depression on PHQ-A screening. He reports years of weight-based bullying at school. His father asks "why can't he just eat less and exercise." [1] [8]

Questions

1. Outline the staged management plan, naming each stage and the escalation trigger. (5 marks) [1] [7]
2. Explain to the father, in biologically accurate terms, why this is a chronic disease and not a willpower problem, and justify the role of pharmacotherapy and surgery. (3 marks) [2] [7]
3. Describe the parallel body-image and mental-health track and why it is core management. (2 marks) [8] [15]

Model answer

Staged management (5). Stage 1 is lifestyle for every patient: at least 60 minutes of moderate-to-vigorous physical activity daily, a sustainable healthy eating pattern, sleep optimisation, and reduced recreational screen time, delivered with motivational interviewing and framed around health behaviours rather than weight. Stage 2 is structured multidisciplinary paediatric weight management adding dietetics, psychology and exercise physiology. Stage 3 is anti-obesity pharmacotherapy, which this boy has reached immediately because he has severe obesity with impaired glucose tolerance; options include metformin for his glucose intolerance and a weight-loss agent such as orlistat or a GLP-1 receptor agonist depending on regional availability. Stage 4 is metabolic and bariatric surgery, for which he may be eligible given a BMI well above 35 with a comorbidity; this is performed at a specialist centre. The escalation trigger is failure to improve after three to six months at the current stage, combined with comorbidity burden and the adolescent's readiness. [1] [7]

Disease framing and escalation rationale (3). Obesity is a chronic disease of excess adiposity with a strong polygenic basis and dysregulated hypothalaptic appetite control through leptin and ghrelin signalling; it is not a willpower problem, and framing it that way worsens outcomes. The impaired glucose tolerance demonstrates that his adipose tissue is already metabolically active and harmful. Because severe obesity rarely responds to lifestyle alone, the evidence supports pharmacotherapy and, where eligible, surgery. The Teen-LABS data show that bariatric surgery achieved markedly better type 2 diabetes outcomes than medical therapy in severely obese adolescents, supporting this as evidence-based rather than extreme care. [2] [7]

Parallel body-image and mental-health track (2). This track runs alongside every stage and is core, not optional. His depression and the years of weight-based bullying are independent predictors of poor engagement, disordered eating and worse obesity trajectory; untreated they undermine every other intervention. I would screen and treat the depression, address the bullying with the school and family, refer to psychology, and use weight-neutral, person-first language throughout, because weight stigma itself worsens every outcome. The depression-obesity relationship is bidirectional, so both are treated concurrently. [8] [15]