Managing obesity in children and adolescents
Obesity during childhood and adolescence is associated with poorer health outcomes in adulthood. Management of obesity during childhood and adolescence can help address current and future health impacts. Diagnosing obesity in this age group can be challenging due to changes in body composition associated with growth and development. Treatment options include behaviour change interventions, intensive dietary approaches, medication and bariatric surgery.
Key Evidence
Behaviour change interventions, including changes to dietary patterns, increased physical activity and decreased sedentary behaviours, is the first-line treatment for children and adolescents living with overweight or obesity
For post-pubertal adolescents with more severe obesity, there may be a need for intensive dietary approaches, medication therapy and bariatric surgery
Interventions should be tailored to the child or adolescent’s developmental stage and delivered in a way that is age-appropriate, engaging and accessible for both the child or young person and their caregivers
Access to high-level care for children and adolescents living with obesity in Australia is limited
While prevention is key to ending obesity in the long term, effective treatment, including weight management, during childhood and adolescence is also vital. It helps to address current and future risks and complications as well as the risk of overweight or obesity persisting into adulthood. Compared to adults, the diagnosis and monitoring of obesity during childhood and adolescence can be challenging due to the rapid growth and development occurring at this time. Body composition also varies by age, sex and stage of growth, for example, pubertal status. As a result, single cut-points cannot be used to define the severity of obesity.1
It's particularly important when assessing, treating or supporting children and adolescents living with overweight or obesity that efforts are made to limit contributing to weight stigma and reducing the associated harms. For more information, see Weight stigma, bias and discrimination.
Assessment
Routine assessment of child growth should be part of standard paediatric clinical practice. When done routinely, abnormal growth patterns are easier to recognise.2 There are various ways of diagnosing overweight and obesity, as discussed below.
1. Body mass index (BMI) is a measure of weight adjusted for height, calculated as weight (kg)/height (m)2. It is the preferred simple screening measure to determine overweight and obesity in children and adolescents. For children, BMI should be plotted on age and sex specific BMI growth charts, such as those from the United States Centers for Disease Control and Prevention (US-CDC) or the World Health Organisation.
Classification of weight status based in this case on the US-CDC growth charts is listed in Table 1.23
Table 1: BMI categories based on US-CDC growth charts
US-CDC Growth Charts
BMI categories based on US-CDC growth charts (percentile) | Recommended terminology |
---|---|
Less than 5th | Underweight |
5th–84th | Healthy weight |
85th–94th | Overweight |
95th-98th | Obesity |
99th onwards | Severe obesity |
2. BMI as a standard deviation score or z-score is used to calculate how far a child’s BMI is above or below the mean (a z-score of 0 is the same as a 50th percentile). It can provide a more accurate representation of change over time than using BMI percentiles alone, particularly for children and adolescents living with overweight or obesity.
For children and adolescents living with severe obesity, BMI expressed relative to the 95th percentile (BMI%95 percentile) is recommended. For example, a child with a BMI%95 percentile of 150 would have a BMI equivalent to 1.5 times the 95th percentile.
3. A waist-to-height-ratio (waist circumference divided by height) of greater than 0.5 is a useful indicator of central adiposity and is predictive of cardiovascular risk in school-aged children and adolescents.4
A thorough clinical history is central to the assessment of a child’s or adolescent’s current and potential future health complications, as well as for assessing their modifiable lifestyle practices. Assessment of psychological and social health should be included. Children and young people living with obesity are especially at increased risk of a range of associated health problems, including poor self-esteem, depression and eating disorders, including binge eating disorder, bulimia nervosa and atypical anorexia nervosa.56 Several brief self-report questionnaires can be used to screen for the possible presence of eating disorders such as Eating Disorder Examination Questionnaire – Short Form (EDE-Q 7), the Eating Disorder Screen for Primary Care (ESP), and the InsideOut Screener. If screening suggests an eating disorder is present, a follow-up comprehensive assessment is recommended. When an eating disorder is confirmed, this should be prioritised in line with the guidelines.
Clinical investigations of potential obesity-associated complications are appropriate in most adolescents living with obesity, and in all people living with severe obesity, with clinical signs or history suggestive of complications, or with a family history risk of type 2 diabetes or premature heart disease. Investigations normally include liver function tests and HbA1c and fasting glucose, lipids and possibly insulin levels. Assessment of micronutrient deficiencies should also be considered.27
Management approaches
The primary aim of obesity management may include a change in weight-related outcomes such as BMI maintenance, reduction or an altered BMI trajectory. In pre-pubertal children living with overweight, and some living with obesity with no weight related complications, weight-related outcomes should centre on weight maintenance rather than weight loss, allowing the child to grow into their body size.8 Other aims may include improvements in obesity-related complications and/or a reduction in markers relating to risk of future complications.9
The first-line approach for child and adolescent obesity management involves behavioural modification to manage weight. In addition, particularly for post-pubertal adolescents living with more severe obesity, there may be a need for intensive dietary approaches, obesity management medications and/or bariatric surgery in combination with support for behaviour change.
Behaviour change intervention
Behaviour change intervention incorporates changes to diet, physical activity and sleep, underpinned by strategies to support behaviour change.
This approach to weight management has several overarching principles7 including:
- management of associated risks and complications
- family involvement
- a developmentally appropriate approach
- long-term behaviour modification:
- dietary change
- increased physical activity
- reduced sedentary behaviours
- improved sleep behaviours
- planning for longer-term weight maintenance.
Dietary counselling should focus on shifting dietary patterns to those that align with the Australian Guide to Healthy Eating, and may include dietary education alone or combined with an energy prescription. Principles of dietary education may include increased intake of fruit and vegetables, reductions in energy-dense nutrient-poor foods and sugar-sweetened beverages, and improved mealtime routines.
Recommendations for physical activity, sedentary behaviour and sleep should be in keeping with the Australian 24-Hour Movement Guidelines for Children and Young People. Addressing physical activity may include incorporating physical activity into daily routines, participation in structured exercise programs or extra-curricular sports/activities and encouraging active transport (e.g. walking or cycling to school). School-aged children and adolescents should incorporate 60 minutes or more of moderate to vigorous physical activity into their day, as well as several hours per day of light activities. Furthermore, recreational screen-time should be limited to less than two hours per day. Changes to improve sleep quality and duration may include modifying bedtime routines and reducing screen time in the evening.
Table 2: Australian physical activity guidelines for children and adolescents
Australian Government Department of Health, Disability and Ageing
https://www.health.gov.au/topics/physical-activity-and-exercise/physical-activity-and-exercise-guidelines-for-all-australians
- | Young Children (2-5 years) | Adolescents (5-17 years) |
---|---|---|
Physical Activity | At least 3 hours per day, with 1 hour being energetic play. | At least 1 hour of moderate to vigorous activity involving mainly aerobic activities per day. |
Vigorous activities should be incorporated at least 3 days per week. | ||
Several hours of light activities per day. | ||
Strength | At least 3 days a week. | |
Sedentary time | Do not restrain for more than 1 hour at a time. | Minimise and break up long periods of sitting. |
No more than 1 hour per day of recreational screen time. | No more than 2 hours per day of recreational screen time | |
Sleep | 10 to 13 hours. Some will still need naps. | 5-13 years: 9 to 11 hours |
14-17 years: 8 to 10 hours |
Strategies to support behaviour change include:
- Goal setting using SMART goals (Specific, Measurable, Achievable, Realistic, Time-bound)
- Parental modelling of the desired behaviour
- Stimulus control (modifying the environment)
- Self-monitoring of behaviour (e.g. food, activity or sleep diaries).
Behaviour change interventions are effective at treating overweight and obesity in the short-term with few studies reporting on long-term outcomes. The 2017 Cochrane reviews1011 found behaviour change interventions to be beneficial for reducing weight, BMI and BMI z-score in children 6-11 years and adolescents 12-17 years living with overweight or obesity. These reviews drew on studies that followed children for up to three years and adolescents for up to two years.
Behaviour change interventions also lead to improvements in physiological and psychological health. Total cholesterol, triglycerides (a type of fat found in blood) and measures of insulin resistance improve following behaviour change interventions.12 Reduced prevalence of obstructive sleep apnoea and increased sleep duration have also been reported.13 Similarly, improvements in psychological health have been seen for most participants, including reduced symptoms of depression and anxiety14, improvements in body image, self-esteem15 and quality of life16 and reduced risk of developing eating disorders17.
Importantly, all such improvements in physiological and psychological health relate to professionally administered programs delivered in a clinical setting or as clinical trials. Access to this type of high-level care in Australia is limited. Little is known about how young people may be managing living with obesity on their own. Observational data suggest that this is predominantly done through dieting with the intention of weight loss. These behaviours, when unsupervised, may be associated with further weight gain, disordered eating and symptoms of depression. Additionally, adolescents may lack appropriate knowledge about physical activity leading to unrealistic or inaccurate beliefs about physical activity, especially over-exercising, and may increase their risk of injury.18 This highlights the importance of increasing access to high quality care.
Intensive dietary approaches
Adolescents with obesity-related risks or complications or more severe obesity may benefit from more intensive dietary approaches. Very Low Energy Diets (VLEDs), consisting of a significantly reduced energy intake of approximately 800kcal/day, and often involving the use of nutritionally complete meal replacement supplements, are one such option. VLEDs are designed to induce ketosis and therefore suppress appetite. Children and adolescents experienced weight reduction in the short-term (up to 20 weeks), with greater weight loss in adolescents, with the use of formulated meal replacements in an inpatient setting.18 Restrictive diets such as these should only be prescribed for short-term use by experienced multidisciplinary teams.
Low-carbohydrate dietary approaches are re-emerging as as a popular method of weight reduction in adults. These typically include a carbohydrate restriction of 30-120g of carbohydrate per day. In adolescents, short-term (< 6 months) low-carbohydrate approaches may have a greater reduction in BMI and BMI z-score when compared to a low-fat intervention, but in the longer term they do not appear to have a more beneficial impact on weight than a standard reduced calorie approach.19 Low-carbohydrate diets may benefit young people with pre-diabetes or type 2 diabetes, insulin resistance or non-alcoholic fatty liver disease and research in these areas is underway.
International paediatric obesity guidelines consistently advise that dietary approaches alone should be avoided, and a multicomponent approach should be recommended in the management of obesity.820
Family-based interventions
The attitudes, beliefs and behaviours of parents and caregivers play a key role in the development and management of obesity in children and adolescents. Parents and caregivers are usually the main decision makers about which foods are available to children at home, and how they are prepared. Parents influence the development of food preferences and eating habits in children. Family-meal times provide an opportunity for parents and caregivers to role model healthy food related behaviours and healthy eating habits. Thus, parents and caregivers are regularly targeted in child weight management interventions.21
Family-based interventions include a range of strategies targeted at parents, such as nutrition and physical activity education sessions, role modelling and behavioural management techniques. Interventions may involve both the parent and child or alternatively the parent only.
An 2019 umbrella review of systematic reviews published between 1990 and 2016, showed that family-based behavioural interventions were effective in achieving successful weight change outcomes (zBMI and percentage overweight) in children and adolescents aged 2-18 years of age.21
Sleep interventions
Poor sleep quality and short sleep duration are emerging as factors in the development of childhood obesity.22 A reduction in sleep duration disrupts the hormonal control of satiety resulting in increased food intake due to inducing hedonic eating or ‘eating for pleasure’ rather than hunger driven eating. Additionally, poor sleep quality and short sleep duration result in fatigue, which in turn lowers energy expenditure and therefore a positive energy balance.2223 Therefore, sleep based strategies have been identified as an approach in the management of obesity in children and adolescents, where earlier bedtime and increased sleep duration may improve eating behaviours and changes in body composition.
A 2020 systematic review reviewed the efficacy of sleep interventions, focusing on either sleep duration or sleep quality interventions or both, for the management of overweight and obesity in children and adolescents23. Only one study identified in the review studied sleep in isolation, with participants being instructed to extend sleep duration by 1 hour and receiving recommendations on sleep hygiene. This study showed that children in the experimental group had a significantly greater reduction in weight and waist circumference, compared to those children in the control group.22
Mixed results were seen in studies where sleep was part of a multicomponent intervention. In these studies, sleep was included as part of education material along with nutrition, physical activity and parenting advice. A meta-analysis comparing behavioural or multicomponent interventions with a sleep component compared to standard care, showed no significant effect on children’s BMI (Cohen’s d 0.18, 95% CI= -0.04, 0.40).22
Drug interventions
Official guidelines for the use of obesity management medications to treat obesity in children and adolescents are not currently available in Australia but are expected to be released late 2025. The Australian Therapeutic Goods Administration (TGA) has approved several drugs for the treatment of obesity in adolescents (12-18 years): phentermine and semaglutide; however none of these medications is listed on the Pharmaceutical Benefits Scheme for obesity management. In combination with behaviour change interventions, obesity management medications may be prescribed if conventional approaches alone have been unsuccessful. Currently, the availability of obesity management medications is very limited, with many having only been trialled in adults.
Metformin (off-label indication) may be prescribed in adolescents with insulin resistance and obesity, and may be associated with diarrhoea, mild abdominal pain or nausea.24
Phentermine remains on private script as an obesity management medication from 12 years of age but is infrequently prescribed. It is not recommended for use in younger children due to its stimulant properties and associated risks including addiction. However, evidence from clinical trials in adults suggest the addiction potential of long-term phentermine use is low.25
Semaglutide (widely known under the brand names Ozempic and Wegovy) is a glucagon-like peptide 1 (GLP1) agonists, approved in Australia for use in type 2 diabetes and obesity management. It is administered as a once weekly subcutaneous injection. Side effects include nausea, abdominal pain, and diarrhoea. Patients may also develop vitamin B12 deficiency. A clinical trial addressed the safety and efficacy of semaglutide in adolescents living with obesity (STEP TEENS). The mean change in BMI over 68 weeks was -16.1% with semaglutide, compared to 0.6% with the placebo.26
Metabolic and bariatric surgery
Guidelines for use of metabolic and bariatric surgery to treat Australian adolescents living with obesity suggest that surgery should be considered:
- in adolescents older than 15 years,
- in those with a BMI >40 kg/m2 or 140% of the 95th percentile without a weight-related complication.
- In those with a BMI >35 kg/m2 or 120% of the 95th percentile with severe weight-related complications, and
- following at least six months of supervised lifestyle modification and obesity management medication.
The adolescent must be able to provide informed consent and understand the operation, potential risks and the need for long-term follow-up.27
Surgical procedures including gastric sleeve, and gastric bypass have shown success in predominantly female adolescents with severe obesity. The mean (95% CI) BMI (kg/m2) change at 36 months post-surgery was −13.0 (−11.0, −15.0) after gastric sleeve and −15.0 (−13.5, −16.5) after gastric bypass.2819 It is important to note that current surgical techniques are associated with complications, including the need for reoperation, the development of excess skin, unpleasant gastrointestinal side-effects (e.g. vomiting) and risk of nutritional deficiencies and osteoporosis.29
In Australia, access to metabolic and bariatric surgery is very limited for adolescents, especially in the public system. A challenge for health care systems in Australia is how to ensure equitable access to appropriate bariatric surgery services for affected adolescents.2
Resources
The NSW Government has developed resources to help health professionals manage children above a healthy weight on the Healthy kids for professionals website
These resources may be particularly useful:
- Guides on how to raise the issue with families in a non-judgemental and supportive way
- Short, free training modules on aspects of child and adolescent obesity for health professionals
- Infographics on eight healthy habits for children and adolescents, available in different languages
- The Go4Fun community treatment program available as a face-to-face program in NSW and online
Weight stigma
Individuals with high body weight experience weight stigma across Australian society, including within education and healthcare systems.30 Body shaming and weight stigma are highly prevalent in children and adolescents with high body weight. They are often targets of teasing, bullying, and weight-based victimisation from their peers, parents and educators, with up to 60-78% of youth with high weight reporting they have experienced weight-based teasing.30
Body shaming and weight stigma increases the risk of psychological distress (particularly symptoms of depression, low self-esteem, and suicidal ideation), poorer social and academic outcomes and, adverse physical health outcomes in youth with high weight.3132 This is further exacerbated by their often lack of engagement in preventative and therapeutic healthcare services.33
A study of secondary school students in Rome, Italy, showed that adolescents who reported experiencing body shaming had higher levels of internalised weight bias (Cohen’s d = −1.128), eating disorder symptoms (Cohen’s d = −1.116), and body size dissatisfaction (Cohen’s d = 0.706) compared to those who did not report body shaming experiences.32
Additionally, weight stigma in youth can also have a long-lasting effect into later life with disordered eating and unhealthy weight control persisting into adulthood.3435
The negative impacts of body shaming and weight stigma on children and adolescents, highlight the need for sensitive and tailored overweight and obesity management support.33 Further information can be found at Weight stigma, bias and discrimination.
Content for this page was written by Eliza Raeburn at Deakin University, and reviewed by Louise Baur Director, NHMRC Centre of Research Excellence in the Early Prevention of Obesity in Childhood - Translate and Consultant Paediatrician, Weight Management Services, The Children’s Hospital at Westmead, NSW; and reviewed by Professor Kate Steinbeck, The University of Sydney and Dr Shirley Alexander, The Children’s Hospital at Westmead, NSW. For more information about the approach to content on the site please see About | Obesity Evidence Hub.