When a Child Is Obese — How Big Is the Problem?

Preamble

A child walks into the clinic and is obviously overweight.

Almost immediately, assumptions begin.

Too much food. Too little exercise. Too much screen time. Perhaps the parents are not doing enough.

But something has changed.

On 7 October 2026, the World Health Organization released its first global guidelines on the integrated management of obesity in children and adolescents. [1][2][3]

Why now?

Because childhood obesity has become a major global health problem—and because WHO identified an important gap in guidance on how to manage it. Obesity is now recognised as a chronic, relapsing disease, arising from complex interactions between biological, environmental, social and behavioural factors. [1][2][3][4]

Malaysia is very much part of this story. NHMS 2024 found that more than one in four Malaysian children and adolescents aged 5–19 were either overweight or living with obesity. [5]

So perhaps it is time to reconsider a familiar question.

When a child is obese, is it the child? The parents? The environment? Could another disease be responsible—or has obesity itself become the disease?

Instead of asking “Whose fault is it?”, perhaps we should ask:

Why is this child gaining excessive weight, is it affecting the child's health, and what can we realistically do about it?

Childhood obesity is influenced by biology, family, diet, physical activity, environment and healthcare. — *Childhood obesity is rarely about one thing. Biology, family, diet, physical activity, the wider environment and healthcare all interact in shaping a child's weight and health.*

1. How Big Is the Problem?

The global numbers are enormous, but what do they mean closer to home?

The National Health and Morbidity Survey (NHMS) 2024: Nutrition gives us the clearest recent Malaysian picture.

Among Malaysian children and adolescents aged 5–19 years, 14.4% were overweight and 13.6% were obese. [5]

Put another way, more than one in four were either overweight or obese.

Obesity was more prevalent among boys, at 16.8%, compared with 10.2% among girls. NHMS used the WHO 2007 BMI-for-age reference for these measurements. [5]

The wider picture is concerning too.

Among adolescents, NHMS 2024 highlighted high levels of physical inactivity and excess dietary fat. The full report also found that approximately two-thirds of adolescents consumed at least one sugar-sweetened beverage a day. [5]

These are not simply statistics about body weight.

They tell us something about the environment in which Malaysian children are growing up.

2. What Exactly Is Childhood Obesity?

Children are not small adults.

For adults, we commonly use fixed BMI cut-offs. In children, BMI has to be interpreted according to age and sex, because body composition changes as a child grows.

For children and adolescents aged 5–19 years, WHO defines: [4][5]

Overweight: BMI-for-age >+1 SD to ≤+2 SD
Obesity: BMI-for-age >+2 SD

NHMS 2024 used these WHO 2007 criteria. [5]

For children under five, WHO Child Growth Standards and different criteria apply.

But one measurement is not the whole story.

The growth trajectory matters.

A child moving progressively upwards across BMI-for-age centiles tells us more than a single weight recorded during one consultation.

3. Before We Blame Anyone

Obesity is visible.

Unfortunately, judgement often follows.

A Malaysian review published in 2026 highlighted persistent misconceptions about obesity among healthcare professionals and healthcare decision-makers. In the surveys cited, 55% of healthcare professionals and 57% of healthcare decision-makers regarded obesity as solely the result of personal behaviour. [7]

If obesity is regarded simply as a failure of self-control, the advice becomes predictable:

Eat less. Move more. Try harder.

Energy balance obviously matters.

But it does not explain why two children living in apparently similar environments can respond very differently.

Nor does it explain why obesity has increased so dramatically within a few generations.

Obesity is not simply a failure of willpower.

And the child did not create the environment in which he or she is growing up.

4. Biology Matters

Appetite is not controlled simply by willpower.

Hunger, satiety and energy expenditure are regulated through complex pathways involving the brain, gastrointestinal tract, adipose tissue and hormones.

Genetics influences susceptibility too.

Rare disorders involving the leptin–melanocortin pathway—including abnormalities involving MC4R, leptin, the leptin receptor and POMC—can produce severe early-onset obesity. [6]

But even without these rare disorders, children differ biologically in their susceptibility to weight gain.

Prenatal influences, early growth, sleep, development and hormonal factors may also contribute.

Our genes have not changed dramatically within a few decades.

Our environment has.

5. Then Is It the Parents?

Parents certainly matter.

They influence what food enters the home, how meals are prepared, portion sizes, sugary drinks and snacks, bedtime routines, screen time, physical activity and the behaviours children see around them.

But parents do not make these decisions in a vacuum.

They are dealing with work schedules, food prices, convenience foods, food delivery, advertising, traffic, concerns about outdoor safety, academic demands and increasingly sedentary lifestyles.

So yes—the family environment matters enormously.

But blaming parents is not the same as helping them.

The better approach is to help the whole family create an environment in which healthier choices become easier.

6. Beyond the Home

A child spends much of the day outside the home.

Schools therefore matter.

So do the foods sold in and around them, opportunities for physical activity, sedentary time and what children learn about nutrition.

Malaysia has previously attempted to address childhood obesity beyond the clinic. One example is Cara Hidup Anda Terbaik (C-HAT), a Ministry of Health and Ministry of Education initiative developed during 2016–2018 to involve parent–teacher associations in healthier eating and physical activity. It illustrates the value of school–family collaboration, but its existence does not establish continuing implementation or long-term effectiveness. [8]

But the problem extends beyond schools.

Can the child walk somewhere safely?

Is there somewhere to play?

Is healthier food affordable and readily available?

What food is being advertised?

How easy is it to order calorie-dense food and sugary drinks to the front door?

The 2026 Malaysian review argues that tackling obesity requires action beyond healthcare, involving education, transport, urban planning, healthier school food and environments that make physical activity easier. [7]

Childhood obesity cannot be treated entirely inside the consultation room.

7. Could It Be Something Else?

Yes—but usually it isn't.

Most childhood obesity is primary or multifactorial rather than the result of a single endocrine disorder. [6]

Nevertheless, occasionally obesity is a clue to something else.

Possible secondary causes include endocrine disorders such as hypothyroidism, Cushing syndrome and growth hormone deficiency; hypothalamic disease or injury; genetic or syndromic disorders; and certain medications. [6]

Rare genetic causes become particularly relevant when obesity is severe, begins very early in life and is accompanied by marked hyperphagia or other unusual clinical features.

The answer is not to investigate every child indiscriminately.

It is to recognise the child whose pattern does not fit.

8. When Should the Alarm Bell Ring?

Look at the growth chart.

One particularly useful clue is height.

A child gaining excessive weight while continuing to grow normally in height is different from a child gaining weight while linear growth is slowing.

Obesity accompanied by poor height velocity or short stature should make us look more carefully for an endocrine or other underlying disorder. [6]

The practical warning signs are a change in the growth pattern, especially slowing height gain; rapid or unusually early weight gain; or neurological, developmental or other unexpected findings. These warrant a closer clinical assessment rather than automatic laboratory screening of every child. [6]

The medication history also matters. Corticosteroids and some antipsychotic and antiepileptic medicines, among others, can contribute to weight gain.

So rather than ordering an indiscriminate battery of tests, ask:

Does the child's growth, development, history or examination suggest that something else is going on?

9. Obesity Can Itself Become the Disease

Even when another disease did not cause the obesity, obesity can eventually become a disease in its own right.

Complications may begin during childhood and adolescence.

These include insulin resistance and type 2 diabetes, hypertension, dyslipidaemia, metabolic dysfunction-associated steatotic liver disease, obstructive sleep apnoea, orthopaedic problems and, in adolescent girls, menstrual abnormalities and polycystic ovary syndrome. [6]

The consequences are not only physical.

There may also be important psychological and social consequences.

That is why childhood obesity should not simply be dismissed as something the child will eventually “grow out of”.

10. Don't Damage the Child While Treating the Weight

There is another complication that doesn't appear on a blood test.

Stigma.

Children living with obesity may be teased, bullied, excluded or shamed—by classmates, relatives and sometimes even healthcare professionals. [1]

The Malaysian literature also describes obesity-related stigma as a potential barrier to healthcare engagement. [7]

So ask about more than weight.

Ask about bullying.

School avoidance.

Anxiety or depression.

Self-esteem.

Body image.

Disordered eating.

Even our language matters. “A child living with obesity” is different from reducing the child to “an obese child”.

We should not damage the child while trying to reduce the child's weight.

The objective is health—not humiliation.

11. What Should We Actually Do?

Malaysia’s 2023 CPG sets out a staged, family-focused approach, with assessment, BMI-for-age measurement, counselling and escalation when needed. For most children, treatment begins with the child and the family. [2][3][6]

Structured management addresses diet, physical activity, sedentary behaviour, sleep and behaviour change.

But that means much more than handing the parents a diet sheet.

What does the family eat?

What does the child drink?

How large are the portions?

How often do they eat outside or order food?

How much does the child sleep?

How much time is spent sitting or looking at screens?

Is physical activity realistically available?

And preferably, changes should involve the whole family rather than isolating the child as the person with “the problem”.

For a younger child who is still growing, success does not necessarily require dramatic weight loss. In some situations, slowing excessive weight gain while height continues to increase can improve BMI-for-age over time. [6]

Parents should seek a medical assessment if a child is gaining weight rapidly, has slowing height growth, snores heavily, experiences significant emotional distress or develops possible obesity-related complications. The aim is to assess growth and health, not simply prescribe a diet. [6]

The target is not simply a lower number on the weighing scale.

It is a healthier child.

12. Age Matters

Childhood obesity is not treated identically at every age.

WHO's new guidance separates children aged 29 days to under 10 years from adolescents aged 10–19 years. [2][3]

For younger children, structured dietary, physical-activity and behaviour-change interventions remain the foundation of treatment. WHO does not recommend pharmacological treatment, bariatric surgery or weight-loss devices for children aged 0–9 years. [2]

For adolescents aged 10–19 years, structured dietary, physical-activity and behavioural care remains the foundation. WHO conditionally suggests pharmacotherapy only when an adolescent has obesity with obesity-related complications and at least six months of structured, supervised multimodal lifestyle intervention has failed to achieve adequate improvement. Prescribing requires a specialised multidisciplinary setting, assessment of physical development and psychological stability, monitoring for adverse effects and long-term follow-up. The evidence supporting this conditional recommendation is of low certainty. [3]

The decision is clinical, not simply a matter of age.

Severity of obesity, associated complications, development, family circumstances and the regulatory approval of any proposed medicine all matter.

13. What About the New Obesity Drugs?

This is where obesity treatment is changing rapidly. WHO issued conditional guidance on GLP-1-based medicines for adults in December 2025, but that adult recommendation does not apply automatically to children or adolescents. Its newer 2026 adolescent guideline permits consideration of pharmacotherapy only under stricter clinical conditions. International recommendations and overseas product approvals do not override Malaysian regulatory indications. [3] [12]

Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of medicines used in obesity treatment. GLP-1 receptor agonists have transformed obesity treatment in adults, and some obesity medicines have also been studied and approved for adolescents in certain countries.

But there is an important trap.

An overseas approval is not a Malaysian indication.

The age indication and current Malaysian-approved product information must be checked for the individual medicine.

In Malaysia, liraglutide 3 mg (Saxenda) is approved for weight management in adolescents aged 12 years and above with obesity and a body weight above 60 kg, together with healthy nutrition and increased physical activity. [9]

The Malaysian product information also specifies that treatment should be discontinued and re-evaluated if BMI or BMI z-score has not fallen by at least 4% after 12 weeks at 3.0 mg/day or the maximum tolerated dose. [9]

This illustrates why we should not simply transfer overseas paediatric indications for drugs such as semaglutide or tirzepatide into Malaysian practice without first checking the current Malaysian product information.

And medication does not replace family-based care.

These are treatments for disease—not cosmetic slimming injections.

14. What Are the Potential Side Effects?

Powerful medicines can produce meaningful benefits.

They can also cause harm.

Common adverse effects of GLP-1 receptor agonists include nausea, vomiting, diarrhoea, constipation and other gastrointestinal symptoms. [9]

More important but less common concerns include dehydration, gallbladder disease and pancreatitis. [9]

In July 2026, Malaysia's National Pharmaceutical Regulatory Agency issued a safety alert concerning severe acute pancreatitis with GLP-1 receptor agonists and dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonists. [10]

Spontaneous adverse-event reports provide important safety signals, but they do not by themselves establish how commonly an event occurs or prove that the medicine caused it.

There is another practical consideration. GLP-1 receptor agonists delay gastric emptying, which may increase the risk of residual gastric contents and pulmonary aspiration during general anaesthesia or deep sedation. [9][11]

A patient receiving one of these medicines should therefore make the treating team aware before undergoing a procedure.

The lesson is simple.

These are medicines. They require proper indication, prescribing, counselling and follow-up.

15. What About Bariatric Surgery?

Surgery in a child sounds extreme.

For most children, it would be.

But severe adolescent obesity can itself be a serious chronic disease.

WHO conditionally suggests bariatric surgery for adolescents aged 10–19 with severe obesity defined by BMI-for-age greater than +4 standard deviations, or greater than +3 standard deviations with obesity-related complications, after at least six months of supervised multimodal lifestyle intervention has not achieved adequate improvement. Surgery should be undertaken only by an experienced multidisciplinary team following assessment of pubertal maturity, final adult height, psychological stability, readiness and long-term follow-up. These are international WHO criteria; Malaysian clinical practice must also take account of the 2023 national CPG and available local specialist services. [3] [6]

The operation is only one part of lifelong care.

Nutritional support, family involvement and continuing follow-up remain essential.

This is not cosmetic surgery.

And it is certainly not a shortcut.

For a very small number of adolescents, however, it may be legitimate treatment for severe disease.

16. So — Is It the Child, the Parents, or the Disease?

Usually, it is not one thing.

Childhood obesity develops through an interaction between biological susceptibility and the environment in which the child grows.

Occasionally, another disease or medication is responsible.

And once established, obesity can itself become a chronic disease.

That is why blame is such a poor treatment.

17. The Kerbside Message

When a child living with obesity sits in front of us, perhaps five questions should come first:

When did it start?

Is the child growing normally?

Could there be an underlying disorder?

Is obesity already affecting physical or mental health?

What can the child, family and environment realistically change?

The arrival of effective obesity medicines is exciting. For carefully selected adolescents, pharmacotherapy—and occasionally bariatric surgery—may now form part of treatment.

But none of this changes the fundamentals.

A child needs a family that is supported rather than blamed.

A school and environment that make healthier choices possible.

And a healthcare system that recognises obesity as a disease without allowing the disease to define the child.

Above all, the child should leave the consultation knowing that we are there to help—not to judge.

Treat the disease. Support the family. Change the environment. Protect the child.

Acknowledgment

I am grateful to Prof Datuk Dr Zulkifli Ismail, Consultant Paediatrician and Paediatric Cardiologist at KPJ Selangor Specialist Hospital and Clinical Professor at KPJ University College of Health Sciences, for his review of this piece and his critical feedback. The judgements and any errors remain mine.

Sources and further reading

Published 45/2026 · 9 October 2026 · No corrections to date · Corrections policy