Synopsis
Measure adiposity accurately, discuss it with permission and without stigma, identify severe early-onset or secondary causes and complications, and offer family-centred multicomponent support that addresses food, activity, sleep, mental health and structural barriers.
- Ask permission to discuss growth, use person-first language and explain that health is influenced by biology, medicines, environment and resources. Do not blame the child or family.
- Measure height and weight accurately and plot BMI centile for age and sex on an appropriate UK chart; adult BMI cut-offs must not be applied to children.
- NICE uses the 91st centile for overweight, 98th for clinical obesity and 99.6th for severe obesity when assessing an individual child.
- Confirm trajectory and growth velocity. Review family history, diet, activity, sedentary time, sleep, medicines, development, puberty, psychosocial wellbeing and social determinants.
- Secondary endocrine causes are uncommon. Reduced linear growth is a key clue; consider genetic disease when obesity is very early, severe or accompanied by hyperphagia or syndromic features.
- Assess blood pressure, sleep-disordered breathing, acanthosis and diabetes risk, lipids, liver disease, puberty and PCOS features, musculoskeletal symptoms and emotional health according to age and severity.
- First-line treatment is family-centred multicomponent support: sustainable dietary pattern, age-appropriate activity, less sedentary time, sufficient sleep and behaviour-change techniques, adapted to culture, disability and family resources.
- Focus on household routines and health outcomes rather than rapid weight loss. In a growing child, weight maintenance with continued height gain can reduce BMI centile.
- Preschool care works through the caregivers. Offer affordable changes such as regular meals, water, fruit and vegetables, less energy-dense drink and snack exposure, active travel and consistent sleep.
- Refer to a specialist service for severe obesity, significant complications, early-onset hyperphagia, suspected secondary disease or unsuccessful primary-care support where services exist.
- Medicines are not routine primary-care treatment. Paediatric pharmacotherapy requires specialist eligibility, current NICE guidance, reproductive counselling where relevant and continued lifestyle support.
- Bariatric surgery is exceptional in young people and requires a specialist multidisciplinary centre, physiological maturity, severe disease and careful long-term nutritional and psychological follow-up.
Key red flags
Polyuria, polydipsia, weight loss, vomiting, abdominal pain or deep breathing requires same-day glucose and ketone assessment for diabetes.
Loud snoring with witnessed apnoea, morning headache, daytime somnolence or school impairment suggests obstructive sleep apnoea.
Severe obesity before age 5, extreme hyperphagia, developmental difference, dysmorphism or a strong monogenic pattern warrants specialist genetic and endocrine assessment.
Poor height velocity alongside weight gain suggests endocrine or systemic disease; simple obesity usually has preserved or increased linear growth.
Headache, visual symptoms, very high blood pressure, hepatomegaly or significant hip or knee pain may indicate an urgent complication.
Bullying, depression, self-harm, binge eating, purging or severe dietary restriction requires direct mental-health and eating-disorder assessment.
Investigation priorities
Confirm weight status and detect disproportionate linear growth.
Management branches
Growth measurements indicate a high BMI centile.
- Confirm height and weight and show the age- and sex-specific trajectory neutrally.
- Ask permission to discuss health, preferred words and the child's priorities.
- Assess causes, complications, mental health and contextual barriers without blame.
The family is ready to work on one or more health behaviours.
- Agree specific affordable changes across food or drinks, movement, sedentary time and sleep.
- Use behaviour techniques such as goals, self-monitoring, problem solving and household environmental change.
- Arrange active follow-up and revise goals from experience, not perceived compliance.