Definition and epidemiology
Childhood obesity is excess adiposity carrying health risk, operationalised through body mass index (BMI) for age and sex because direct fat measurement is impractical. India now reports one of the world’s largest absolute burdens of childhood overweight, driven by urbanisation, energy-dense diets and reduced activity, while undernutrition persists — a dual burden. Obesity tracks into adulthood and clusters with insulin resistance, dyslipidaemia, hypertension and non-alcoholic fatty liver disease, with the metabolic risk emerging at lower BMI thresholds in South Asian children.
Clinical features
Most childhood obesity is exogenous (lifestyle-driven): the child is tall for age with advanced or normal bone age, normal development, and a family history of obesity. Look for acanthosis nigricans (insulin resistance), striae, hip/knee pain (SCFE, Blount disease), snoring/daytime somnolence (OSA), menstrual irregularity and hirsutism (PCOS in adolescent girls), and psychosocial distress. By contrast, short stature with obesity or developmental delay points away from simple obesity toward an endocrine or syndromic cause.
Diagnosis
Plot BMI on the correct reference. For children under 5 years, use WHO weight-for-length/height standards (overweight >+2 SD, obesity >+3 SD). For 5–18 years in India, the IAP 2015 BMI charts are preferred over international references because Indians develop cardiometabolic risk at lower BMI: cut-offs are adjusted to adult equivalents of 23 kg/m² (overweight) and 27 kg/m² (obesity). Using CDC/WHO references, overweight is BMI ≥85th and obesity ≥95th percentile for age and sex (WHO 5–19y: overweight >+1 SD, obesity >+2 SD). Severe obesity is ≥120% of the 95th percentile. Assess waist circumference, blood pressure, and screen comorbidities (fasting glucose/HbA1c, lipids, ALT, plus thyroid/PCOS work-up where indicated).
See the full criteria: Childhood Obesity
Red flags
- Short stature or declining height velocity with weight gain — endocrine cause (hypothyroidism, Cushing, GH deficiency)
- Developmental delay, dysmorphism, hyperphagia — syndromic obesity (e.g. Prader–Willi, monogenic leptin/MC4R defects)
- Early-onset severe obesity before age 5 years
- Headache/papilloedema (idiopathic intracranial hypertension), hip/knee pain (SCFE), severe OSA
- Polyuria/polydipsia or acanthosis with symptoms — type 2 diabetes
Management overview
Management is multidisciplinary, family-centred lifestyle intervention targeting sustainable diet quality, reduced screen time, ≥60 minutes of daily activity, adequate sleep and behavioural support — with weight maintenance (allowing height to “catch up” BMI) often the goal in growing children rather than weight loss. Screen and treat comorbidities. Pharmacotherapy (e.g. GLP-1 receptor agonists in adolescents) and bariatric surgery are reserved for severe obesity with comorbidity in specialist settings, after structured lifestyle measures. Avoid stigmatising language; engage the whole family, as parental habits strongly predict outcome. Re-plot growth at each visit and watch for the red flags above signalling a secondary cause.
References
- IAP. Indian Pediatr. 2023;60:1013 (pediatric obesity consensus guidelines).
- Khadilkar V, et al. Indian Pediatr. 2015;52:47–55 (revised IAP 2015 growth charts).
- WHO Child Growth Standards / Growth Reference 5–19y; CDC Clinical Growth Charts.
Decision support for qualified clinicians only — verify against current primary guidelines and your clinical judgement.