Definitions
- Overweight: BMI 85th–94th percentile for age/sex
- Obese: BMI ≥95th percentile for age/sex
- Severe obesity: BMI ≥120% of 95th percentile
- Must use age/sex-specific growth charts — NOT adult BMI cut-offs
BMI in children is plotted on centile charts and interpreted per age/sex band — not by the adult 25/30 cut-offs.
Causes
| Category | Examples |
|---|
| Lifestyle (most common) | High-calorie diet, sedentary lifestyle, >2h/day screen time |
| Genetic predisposition | Family history, maternal obesity, FTO gene |
| Endocrine (<1%) | Hypothyroidism, Cushing's, growth hormone deficiency |
| Genetic syndromes (rare) | Prader-Willi (hypotonia + hyperphagia), Bardet-Biedl |
Suspect endocrine/syndrome cause if: short stature, developmental delay, dysmorphic features. Always check TFTs.
Clinical Assessment
- Height + weight → BMI centile on growth chart
- Waist circumference ≥90th percentile = central adiposity
- Blood pressure (correct cuff size for age/height)
- Acanthosis nigricans at neck/axilla = insulin resistance marker
- Hepatomegaly = NAFLD; hip pain/limp = SCFE; snoring = OSA
Investigations
| Test | Reason |
|---|
| Fasting glucose + HbA1c | T2DM / pre-diabetes |
| Fasting lipids | Dyslipidaemia (↑TG, ↓HDL) |
| LFTs + USS abdomen | NAFLD |
| TFTs | Exclude hypothyroidism |
| Vitamin D + iron | Common deficiencies in GCC |
| Polysomnography | OSA if snoring/sleepy |
Psychosocial Assessment
- Screen for depression, anxiety, bullying, social isolation
- Screen time hours/day; physical activity habits
- Family dietary habits; parental BMI
Use weight-neutral language — focus on health behaviours, not weight. Never use the word "fat" in consultations.
Complications
| System | Complication |
|---|
| Metabolic | T2DM, pre-diabetes, metabolic syndrome, dyslipidaemia |
| Liver | NAFLD → NASH → cirrhosis (long-term) |
| Cardiovascular | Hypertension, early atherosclerosis |
| Respiratory | OSA (obstructive sleep apnoea) |
| Musculoskeletal | SCFE (hip pain/limp), Blount's disease (tibial bowing) |
| Neurological | Pseudotumour cerebri (headache + visual changes) |
| Psychosocial | Depression, anxiety, bullying, low self-esteem |
| Endocrine | PCOS in girls, early puberty |
SCFE: Obese child + hip/knee pain + limp = SCFE until proven otherwise. Non-weight-bearing + urgent X-ray + orthopaedic referral immediately.
GCC countries have some of the world's highest childhood obesity rates — UAE ~35%, Saudi Arabia ~30–40% of school-age children. Rapid urbanisation, AC indoor culture, high-calorie diet, and reduced outdoor activity due to extreme heat all contribute.
Post-Iftar high-calorie meals, late-night eating, and disrupted sleep during Ramadan can worsen obesity in at-risk children. Counsel families on balanced Iftar/Suhoor. Younger children not fasting may still experience household dietary disruption.
UAE: Dubai Fitness Challenge (30×30), school health programmes (OSHC). Saudi Arabia: Vision 2030 healthy living targets, school canteen regulations. Qatar: National Health Strategy childhood obesity priority. School nurses are key for BMI surveillance and referral pathways.
In many GCC cultures, a chubby child is seen as healthy. Parents may resist weight management discussions. Frame conversations around health, energy, and wellbeing — not appearance. Engage both parents; father's buy-in is often critical in GCC family dynamics.
High-Yield Exam Points
- Childhood obesity = BMI ≥95th percentile (NOT adult cut-offs)
- Acanthosis nigricans = insulin resistance marker
- SCFE: obese child + hip pain + limp → non-weight-bearing + X-ray
- Prader-Willi: neonatal hypotonia + hyperphagia + short stature + intellectual disability
- First-line: family-based lifestyle intervention
- Orlistat licensed from age 12
- Physical activity target: ≥60 min/day; Screen time: <2 h/day
1. A 10-year-old boy has BMI on the 97th centile, fasting glucose 6.2 mmol/L, and dark velvety patches at his neck. Most important next investigation?
A. TFTs
B. Cortisol
C. Oral glucose tolerance test
D. Insulin level
✓ Acanthosis nigricans + raised fasting glucose = insulin resistance/pre-diabetes → OGTT to confirm.
2. An obese 13-year-old girl has 2 weeks of right hip pain and a limp. She is afebrile. Immediate action?
A. Reassure — likely growing pains
B. Non-weight-bearing, urgent hip X-ray, orthopaedic referral
C. NSAIDs and physiotherapy
D. MRI knee
✓ SCFE — obese adolescent + hip pain + limp = SCFE until proven otherwise. Missing it risks avascular necrosis.
3. First-line treatment for a 9-year-old with obesity?
A. Orlistat 120mg with each meal
B. Very low calorie diet <800 kcal/day
C. Family-based lifestyle intervention
D. Bariatric surgery referral
✓ Family-based lifestyle intervention is always first-line. Orlistat is only licensed from age 12.
4. Features of Prader-Willi syndrome include:
A. Tall stature, hyperactivity, normal intelligence
B. Neonatal hypotonia, hyperphagia, short stature, intellectual disability
C. Macrocephaly, seizures, normal weight
D. Early puberty, rapid growth, high BMI only
✓ Prader-Willi (chr 15q11-13) = neonatal hypotonia → hyperphagia from childhood → obesity + short stature + intellectual disability.