How do I know if my child is overweight?

Unlike adults, overweight and obesity in children is not defined by a fixed BMI number — it depends on the child's age and sex. Your GP plots your child's BMI on a growth chart and compares it to other children of the same age and sex using CDC centile charts. Overweight is BMI at or above the 85th centile; obese is at or above the 95th centile. A single reading is less informative than the trend over time — whether the BMI centile is rising, stable, or falling matters more than any one measurement.

What is the most important change a family can make?

The evidence consistently points to eliminating sugar-sweetened beverages as the single dietary change with the clearest effect on BMI in children. This includes soft drinks, fruit juice, cordial, sports drinks, and flavoured milk. A can of soft drink contains approximately 150 calories with no nutritional benefit, and liquid calories do not produce the same sense of fullness as solid food. Replacing all these drinks with water and plain milk can meaningfully reduce energy intake without restricting meals, and is the recommended starting point before any other dietary change.

Can medications like semaglutide be used for a teenager with obesity?

Semaglutide (Wegovy) is TGA-approved in Australia for adolescents aged 12 and over with obesity, based on the STEP-TEENS trial showing approximately 16% BMI reduction over 68 weeks. However, as of mid-2026, semaglutide is not PBS-listed for obesity at any age — the cost is around $300–400 per month privately. It is not a first-line treatment: intensive lifestyle intervention should be the foundation. When pharmacotherapy is considered for adolescents with severe obesity and significant comorbidities, this involves a paediatric specialist and careful monitoring.

Is childhood obesity a parenting failure?

No. Obesity is a chronic medical condition shaped by genetics, environment, food systems, socioeconomic factors, and biology — not a failure of willpower or parenting. Children from lower socioeconomic backgrounds, families with food insecurity, and communities with limited access to fresh food and safe outdoor spaces are disproportionately affected. Weight stigma — the judgement attached to body size — independently worsens health outcomes and is itself a clinical harm. GP management is always non-stigmatising, family-centred, and focused on health behaviours rather than treating weight as a moral issue.

When does a child need to see a specialist?

Refer to a paediatrician or paediatric endocrinologist when: the child's height is not keeping pace with expected growth alongside weight gain, suggesting an endocrine cause such as hypothyroidism, Cushing syndrome, or growth hormone deficiency; there are features of a genetic syndrome such as developmental delay, unusual facial features, or hyperphagia onset before age 5; significant comorbidities are present such as type 2 diabetes, obstructive sleep apnoea, elevated liver enzymes, hip pain, or slipped upper femoral epiphysis; or there is no meaningful improvement after 6–12 months of structured family lifestyle intervention.

Childhood and adolescent obesity

Childhood and adolescent obesity: the AU general-practice framework

By Dr HB Lo, FACRRM Reviewed 18 July 2026 10 min read

Childhood obesity: overweight ≥85th BMI centile, obese ≥95th, severely obese ≥120% of the 95th centile. About 25–27% of Australian children are above a healthy weight; Aboriginal and Torres Strait Islander children are affected at roughly twice that rate.

Family-centred lifestyle intervention is first line: eliminating sugar-sweetened beverages is the most impactful dietary change. A GP Chronic Condition Management Plan funds dietitian, exercise physiologist, and psychology care. Daily activity ≥60 minutes and screen time ≤2 hours are the behavioural targets.

Semaglutide is TGA-approved for adolescents ≥12 years but not PBS-listed for obesity; private access costs ~$300–400 per month.

Childhood obesity is one of the most prevalent chronic conditions presenting to Australian GPs — about 25–27% of children and adolescents aged 5–17 years are overweight or obese, according to AIHW surveillance data. The overall prevalence has plateaued since approximately 2015, but the socioeconomic gradient is widening: children in the lowest socioeconomic quintile are approximately twice as likely to be obese as those in the highest quintile. Aboriginal and Torres Strait Islander children experience obesity at roughly twice the rate of non-Indigenous children.

The condition is not simply a risk factor — it is itself a chronic, relapsing disease with significant consequences in childhood: type 2 diabetes, obstructive sleep apnoea, non-alcoholic fatty liver disease (MASLD), slipped upper femoral epiphysis, depression, and bullying. Approximately 80% of obese adolescents will be obese adults.

The GP encounter is the primary opportunity for early identification, family counselling, and coordinated care. The guiding principle throughout is non-stigmatising, family-centred, person-first communication — obesity develops in environments, not through moral failure.

A. Core clinical — the AU general-practice framework

Classification by BMI centile

Unlike adult BMI thresholds, paediatric obesity is defined relative to age and sex:

Overweight: BMI ≥85th and <95th centile for age and sex
Obese: BMI ≥95th centile
Severe (Class II) obesity: BMI ≥120% of the 95th centile or BMI ≥35, whichever is lower
Class III obesity: BMI ≥140% of the 95th centile or BMI ≥40

Use CDC growth charts for children aged 2 years and older (AU convention). Use WHO growth standards for under 2 years.

Plot at every visit — single static BMI misses trajectory crossings, which carry clinical significance before crossing the 95th centile line. Waist circumference is a useful adjunct for visceral adiposity in older children.

Red flags that must not be missed

These patterns suggest a secondary cause of obesity and require urgent investigation or referral:

Height deceleration alongside weight gain — endocrine cause: hypothyroidism, Cushing syndrome, growth hormone deficiency; check TSH, 8 am cortisol, IGF-1
Dysmorphic features + developmental delay + hyperphagia onset before age 5 — genetic syndrome: Prader-Willi (confirmed by DNA methylation), Bardet-Biedl (polydactyly + retinal dystrophy), MC4R or LEPR monogenic obesity
Acanthosis nigricans + hypertension + polyuria — screen for type 2 diabetes: fasting glucose + HbA1c
Hip or knee pain in an overweight pubertal child — slipped upper femoral epiphysis (SUFE): orthopaedic emergency
Snoring, witnessed apnoeas, daytime sleepiness, school performance decline — obstructive sleep apnoea
Suicidality, eating-disorder features, severe bullying — psychological emergency: Mental Health Care Plan

History

The history explores energy balance drivers without blame:

Dietary pattern — typical day, sugar-sweetened beverage (SSB) intake (cans of soft drink, juice boxes, cordial, sports drinks), snack frequency, take-away food, eating at the table versus in front of screens
Physical activity — minutes of moderate-vigorous physical activity (MVPA) per day, organised sport, active transport to school
Screen time — combined daily non-school hours (TV + phone + tablet + gaming console)
Sleep — bedtime, wake time, hours, snoring or restless sleep
Mental health — mood, anxiety, body image, binge eating or loss-of-control eating episodes, school bullying
Family history — obesity, type 2 diabetes, cardiovascular disease under 55, bariatric surgery in parents
Medications — glucocorticoids, antipsychotics (olanzapine, risperidone, quetiapine), antiepileptics (valproate, gabapentin), tricyclic antidepressants, insulin
Social determinants — food security, housing stability, parental mental health, family violence
Pubertal status and, if post-menarchal, cycle regularity

Examination

Height, weight, BMI plotted on CDC chart — show the curve to the child and parent
Blood pressure with a correctly sized paediatric cuff; compare to paediatric centile tables
Waist circumference
Tanner staging
Acanthosis nigricans — neck, axillae, knuckles (marker of insulin resistance)
Dysmorphic features: facies, hands, eyes
Cushingoid features — moon facies, buffalo hump, striae, proximal weakness
Tonsillar grade (Brodsky) for OSA risk
Hip and knee gait — SUFE
Skin — striae, intertrigo, hidradenitis suppurativa

Investigations

Per AAP 2023 CPG and NHMRC 2013 guidelines:

All children aged ≥10 years with BMI ≥95th centile:

Fasting glucose and HbA1c
Fasting lipid panel (TC, LDL-C, HDL-C, triglycerides)
ALT (MASLD screen)
TSH

Severe obesity or suspicion of secondary cause: add 8 am cortisol, IGF-1, PCOS workup (if post-menarchal), sleep study if symptoms, liver ultrasound if ALT elevated.

B. Evidence appraisal — what works

Family-centred intensive lifestyle intervention

The Cochrane review by Mead 2017 — 70 RCTs in children aged 6–11 — demonstrates that combined diet, physical activity, and behavioural intervention significantly reduces BMI z-score compared to control. Family-based interventions outperform child-only approaches. The AAP 2023 CPG recommends intensive health-behaviour and lifestyle treatment (IHBLT) of ≥26 contact hours per year as the evidence-based standard.

The critical honest caveat for Australian general practice: the MBS GP Chronic Condition Management Plan allows access to 5 allied health sessions per year (10 for Aboriginal and Torres Strait Islander patients), which is well below the IHBLT threshold of 26 hours. Community and school-based supplementation is needed to bridge the gap.

Sugar-sweetened beverage elimination

Eliminating sugar-sweetened beverages is consistently identified as the single most effective individual dietary intervention for paediatric obesity. The Heart Foundation and WHO both recommend restricting free sugars to less than 10% (ideally under 5%) of energy intake. Liquid calories — from soft drink, juice, cordial, and sports drinks — bypass satiety signalling in a way solid food does not.

GLP-1 receptor agonists in adolescents

The STEP-TEENS trial (Weghuber NEJM 2022) — 201 adolescents with obesity on semaglutide 2.4 mg weekly versus placebo over 68 weeks — showed:

BMI reduction of 16.1% versus +0.6% in placebo
73% achieved ≥5% weight loss versus 18% on placebo

Semaglutide (Wegovy) and liraglutide (Saxenda) are both TGA-approved for adolescents aged 12 and over with obesity. Neither is PBS-listed for obesity in Australia as of mid-2026. Private cost is approximately $300–400/month for semaglutide. Rebound on cessation is substantial, and long-term effects on pubertal development and bone mineral density require ongoing surveillance.

Bariatric surgery in severe adolescent obesity

The Teen-LABS trial (Inge NEJM 2016) — 242 adolescents — demonstrated 28% BMI reduction at 3 years; 95% type 2 diabetes remission, 86% dyslipidaemia remission, and 76% hypertension remission with sleeve gastrectomy or Roux-en-Y gastric bypass. Five-year follow-up confirmed durable outcomes. Surgery is appropriate from age ≥14 years with severe obesity and significant comorbidities, at tertiary paediatric centres (RCH Melbourne, Sydney Children’s Hospital, Westmead, Queensland Children’s Hospital). Lifelong micronutrient monitoring is mandatory.

C. Management approach

The stepwise approach in Australian general practice:

Step 1 — All children above healthy weight:

Universal BMI plot at every encounter; share the centile chart with the family
Non-stigmatising conversation using person-first language (“a child with obesity” not “an obese child”)
SSB elimination as the first dietary goal — concrete, measurable, effective
Australian Dietary Guidelines: 5 vegetables + 2 fruit + wholegrains + lean protein; minimise ultra-processed foods
Australian 24-Hour Movement Guidelines: ≥60 min MVPA daily; screens <2 h/day non-school; appropriate sleep hours

Step 2 — Obese (≥95th centile) or overweight with comorbidities:

Investigations (above)
GPCCMP (items 965/967 post-1 July 2025): open a care plan and access allied health
Dietitian (MBS item 10954), exercise physiologist (10953), psychology (10968) — 5 sessions/year (10 for ATSI)
Mental Health Care Plan (items 2715/2717) if mental health comorbidity or eating-disorder concern
Review at 3 months; adjust plan

Step 3 — Severe obesity or obese without improvement at 6–12 months:

Paediatrician referral for specialist-led assessment
Tertiary weight management programme if available
Pharmacotherapy consideration ≥12 years under specialist guidance (private cost; not PBS for obesity)
Bariatric surgery consideration ≥14 years with comorbidities at tertiary paediatric centre

Language and communication:

Never use weight as a moral category
Frame all conversations around health behaviours and family wellbeing, not appearance or willpower
Co-design goals with the child and parents; avoid parental blame
Screen for disordered eating at every step — weight-focused intervention can trigger restrictive or binge eating patterns in susceptible individuals

D. Australian operations

MBS items (verify before billing)

Standard consultations: 23 / 36 / 44 (level B/C/D)
Healthy Kids Check (age 4): item 709 — opportunity to plot growth and initiate a weight conversation
ATSI Health Assessment: item 715 + follow-up 10987 — 10 allied health sessions/year under CDM for ATSI patients
GPCCMP: preparation 965, review 967 — obesity with chronic comorbidity (type 2 diabetes, MASLD, OSA, hypertension, psychological) qualifies
Allied health under CDM: dietitian 10954, exercise physiologist 10953, psychology 10968 — 5 sessions/year total (10 for ATSI)
Mental Health Care Plan: 2715 / review 2717 — psychology up to 10 sessions; critical when body image, eating disorder, or depression is present
Paediatric pathology bundle: HbA1c + fasting glucose + lipids + ALT + TSH — verify current item numbers
Sleep study: paediatric item 12203 (via paediatrician or sleep physician referral)

PBS medications

Orlistat — PBS Authority for adolescents aged ≥12 with obesity meeting criteria; GI side effects (steatorrhoea) frequently limit use in practice
Metformin — PBS for type 2 diabetes; off-label for PCOS in adolescents; modest weight effect in insulin-resistant patients
Semaglutide (Wegovy), liraglutide (Saxenda) — NOT PBS-listed for obesity; TGA-approved adolescents ≥12; private cost $300–400+/month — a significant equity barrier
Levothyroxine — PBS general if hypothyroidism is identified as a secondary cause

ATSI considerations

Aboriginal and Torres Strait Islander children experience obesity at approximately twice the rate of non-Indigenous children. Every 715 ATSI Health Assessment is an opportunity to plot growth and initiate a culturally safe weight conversation. Community-led programmes such as Deadly Choices are more effective than adapted mainstream models. Ten allied health sessions per year are available under CDM for ATSI patients. Engage local Aboriginal Community Controlled Health Organisations (ACCHOs) where available.

E. Special populations

Aboriginal and Torres Strait Islander children. Culturally safe, community-led approaches are essential; dietary advice must account for cultural food practices, food security, and community resources. The higher allied health allowance (10 sessions) under CDM for ATSI patients provides a meaningful advantage.

Rural and remote families. Telehealth dietitian, psychologist, and paediatrician consultations substantially extend reach. Set a lower threshold for tertiary paediatric referral given scarce local MDT services.

Children on weight-promoting medications. Children on antipsychotics, antiepileptics (valproate), or chronic corticosteroids require proactive growth monitoring. Wherever possible, involve the prescribing specialist in weight-sparing alternatives and work within the MDT to balance psychiatric or neurological needs against metabolic risk.

Adolescents transitioning to adult care. Coordinate the handover at approximately 16–18 years: link to adult obesity management services, update the care plan, and ensure comorbidities are transferred with the patient. The adult obesity management framework is addressed in the obesity-metabolic-syndrome article.

Children with eating-disorder features. Obesity and disordered eating frequently co-exist. Binge eating disorder, loss-of-control eating, and restrictive eating all warrant specific management. If disordered eating is present, a weight-neutral or Health At Every Size approach may be appropriate; specialist ED assessment via a Child and Adolescent Mental Health Service (CAMHS) may be needed before pursuing intensive weight-focused intervention.

When to escalate

Urgent / same-day:

Suspected SUFE — atraumatic hip or knee pain in an overweight pubertal child; do not delay orthopaedic referral
Suicidal ideation or active self-harm in an adolescent with obesity
Severe eating-disorder presentation — admission may be needed

Early paediatric or specialist referral:

Suspected endocrine cause (height deceleration + weight gain): paediatric endocrinology
Suspected genetic syndrome (Prader-Willi, Bardet-Biedl, monogenic obesity): paediatric genetics
Significant comorbidity — type 2 diabetes, OSA requiring CPAP, MASLD with elevated ALT, severe hypertension: paediatrician
No improvement after 6–12 months of structured GP-led family intervention: paediatrician
Severe obesity ≥120% of 95th centile or BMI ≥35: tertiary weight management programme
Mental health comorbidity with eating-disorder features: CAMHS

What this article is and is not

This is general health information drawn from current Australian and international guidelines — the NHMRC Overweight and Obesity CPG, RACGP SNAP guideline, Australian Dietary Guidelines, AAP 2023 CPG, and major trials. It is not personal medical advice and does not replace assessment by your child’s GP or treating clinician.

Decisions about specific investigations, referral, and pharmacotherapy are made through the treating clinical relationship. For Australian consumer resources: HealthDirect — Childhood obesity, Better Health Channel.

Sources cited

Frequently asked questions

How do I know if my child is overweight?

Unlike adults, overweight and obesity in children is not defined by a fixed BMI number — it depends on the child's age and sex. Your GP plots your child's BMI on a growth chart and compares it to other children of the same age and sex using CDC centile charts. Overweight is BMI at or above the 85th centile; obese is at or above the 95th centile. A single reading is less informative than the trend over time — whether the BMI centile is rising, stable, or falling matters more than any one measurement.
What is the most important change a family can make?

The evidence consistently points to eliminating sugar-sweetened beverages as the single dietary change with the clearest effect on BMI in children. This includes soft drinks, fruit juice, cordial, sports drinks, and flavoured milk. A can of soft drink contains approximately 150 calories with no nutritional benefit, and liquid calories do not produce the same sense of fullness as solid food. Replacing all these drinks with water and plain milk can meaningfully reduce energy intake without restricting meals, and is the recommended starting point before any other dietary change.
Can medications like semaglutide be used for a teenager with obesity?

Semaglutide (Wegovy) is TGA-approved in Australia for adolescents aged 12 and over with obesity, based on the STEP-TEENS trial showing approximately 16% BMI reduction over 68 weeks. However, as of mid-2026, semaglutide is not PBS-listed for obesity at any age — the cost is around $300–400 per month privately. It is not a first-line treatment: intensive lifestyle intervention should be the foundation. When pharmacotherapy is considered for adolescents with severe obesity and significant comorbidities, this involves a paediatric specialist and careful monitoring.
Is childhood obesity a parenting failure?

No. Obesity is a chronic medical condition shaped by genetics, environment, food systems, socioeconomic factors, and biology — not a failure of willpower or parenting. Children from lower socioeconomic backgrounds, families with food insecurity, and communities with limited access to fresh food and safe outdoor spaces are disproportionately affected. Weight stigma — the judgement attached to body size — independently worsens health outcomes and is itself a clinical harm. GP management is always non-stigmatising, family-centred, and focused on health behaviours rather than treating weight as a moral issue.
When does a child need to see a specialist?

Refer to a paediatrician or paediatric endocrinologist when: the child's height is not keeping pace with expected growth alongside weight gain, suggesting an endocrine cause such as hypothyroidism, Cushing syndrome, or growth hormone deficiency; there are features of a genetic syndrome such as developmental delay, unusual facial features, or hyperphagia onset before age 5; significant comorbidities are present such as type 2 diabetes, obstructive sleep apnoea, elevated liver enzymes, hip pain, or slipped upper femoral epiphysis; or there is no meaningful improvement after 6–12 months of structured family lifestyle intervention.

Source quality

Sources grouped by evidence tier. AU primary tier first; international where AU is silent or lagging; named-author reconstruction where guidelines have not yet caught up. How tiers work.