Childhood obesity

If you are worried that your child may be above a healthy weight, you’re not alone. In Australia, more than one in 4 kids aged 5-17 years is overweight. Recognising that your child is above a healthy weight and helping them to make changes to their diet and activity levels will improve their health and wellbeing.

How do I know if my child is overweight?

Children’s weight is usually monitored by doctors and other health professionals during regular check-ups from birth. If you are concerned that your child may be overweight, a proper clinical assessment by your general practitioner (GP) is recommended.

See your doctor

Your doctor will ask about your child’s usual diet and how much activity they do. They will also ask about their health in general, and whether they are taking any medicines.

Your doctor will weigh your child and work out whether they are in a healthy weight range using growth charts, also known as percentile charts (see below).

As part of their assessment, your doctor will check whether your child has any other health problems and may also order some blood tests.

Growth charts

Children younger than 2 years of age will routinely have their growth tracked on growth charts to give an indication of whether they are developing and growing as expected for their age.

A child may be overweight if their weight is above the 97th percentile on growth charts and they are gaining weight rapidly. Your doctor or health care nurse will let you know if your child’s weight is outside the healthy range.

Body mass index (BMI)

As children get older, their weight can be checked using body mass index (BMI). Doctors calculate the BMI using the same method as for adults — weight in kilograms divided by height in metres squared (kg/m2). BMI measurements are used to assess weight in children older than 2 years.

BMI results need to be interpreted using an age-adjusted chart or a BMI calculator specifically for children, because normal BMI ranges vary according to the age and gender of a child.

Children above the 85th percentile on a BMI chart are classed as overweight. Those above the 97th percentile on the World Health Organization BMI chart (or the 95th percentile on CDC charts) are classed as obese. If you are told that your child’s BMI is on the 85th percentile, this means that 85 per cent of children of the same age and sex will have a lower BMI than your child.

Waist circumference

Sometimes doctors also measure waist circumference as part of their weight assessment.

Why is my child overweight? Is it lifestyle or genetics?

There are a number of interacting factors that can lead to weight problems in children.

The main external influence on weight gain is energy imbalance. When our energy intake (from food and drinks) is roughly equal to the energy we expend (or burn) through activity, we maintain a fairly constant weight. When the balance moves towards more energy intake, we gain weight; when it moves towards greater energy expenditure or reduced energy intake, we lose weight.

Energy imbalance comes about when we eat too many of the wrong foods and/or don’t move enough. More frequent eating out in restaurants or eating fewer meals as a family can increase the quantity and reduce the quality of the food we eat. And with increasing use of technology among children, it’s not uncommon for screen time to start regularly replacing outdoor activity.

Certain metabolic and hormonal conditions, some of which are genetic, can cause weight problems in children. However, these conditions are rare.

Genetic (inherited) factors can also contribute to a child’s tendency to become overweight. Some medicines can also cause weight gain.

What health problems are associated with being overweight?

As well as the physical discomfort of being overweight, children can experience health problems such as:

  • bone and joint problems;
  • shortness of breath on exertion or asthma;
  • heat intolerance;
  • tiredness;
  • high blood pressure;
  • abnormal blood fat (cholesterol) levels;
  • type 2 diabetes; and
  • obstructive sleep apnoea (episodes of disturbed breathing during sleep) which can lead to problems with concentration and learning performance.

Being above healthy weight is also linked with early puberty.

Overweight children may also experience social problems and psychological distress. They may develop a negative self-image and, in some cases, low self-esteem. This may be related to how they are treated by other children, how they perform at sports and how they look. They may face bullying or teasing from other children and be at increased risk of anxiety and depression.

There are also some long-term health problems associated with being above a healthy weight in childhood. Being overweight as a child increases the risk of you being overweight in adulthood. It can also increase the risk of developing several other health problems as an adult, including:

But you can minimise the risk of developing health problems by adjusting your child’s diet and the amount of physical activity they get each week.

Treating weight problems in children

Your doctor may suggest a healthy lifestyle and weight management programme or refer your child to a dietitian or paediatrician (specialist in children’s health). Weight management in children usually means aiming to slow or stop weight gain, rather than losing weight. That means that your child will achieve a healthy weight as they grow taller.

Losing weight may be recommended for children who have health problems associated with their weight or those who are obese.

Weight management programmes generally involve long-term changes in diet and physical activity. Behaviour modification (altering attitudes towards snacking and mealtimes) and family support for eating and behaviour change are extremely important.

This may involve making time to eat breakfast, changing your shopping and cooking practices and getting your child to take a packed lunch to school. Research has shown that when the family is included in the treatment programme, long-term success rates are much higher than when they are not.

Tips to reach a healthy weight

Reduce energy intake by reducing the amount of fat and sugar in the diet. Start by stopping any soft drinks and other sugar-containing drinks. Encourage your child to eat regular meals, have healthy snacks (such as fruit and vegetables) available, make sure portion sizes are appropriate and remove tempting treat foods from your home.

Increase physical activity to improve both physical and mental health. Find opportunities to be more active day to day. Walking to school or the shops or walking the dog are some ways to build more activity into your week. Organised activities and formal exercise programmes are a good way of keeping active and building self-esteem.

Decrease sedentary (sitting) activities. Limit the number of hours of screen time (including watching television, using computers, smartphones and tablets, and playing electronic games) to a maximum 2 hours per day.

How do I manage my child’s diet without affecting their growth?

Some people worry that their children will miss out on the fuel they need to develop while trying to achieve a healthy weight.

It’s true that it’s important not to exclude foods that your child needs for growth and development - adequate quantities of cereals, vegetables, fruits, lean meats (or alternatives such as fish, eggs, beans, pulses and nuts) and dairy foods are part of a healthy diet. You should avoid being too restrictive or controlling with food.

But there’s little downside to limiting foods and drinks that are high in calories but low in nutrients. These include take away foods, pre-packaged, highly processed foods and sugary drinks (soft drinks, sports drinks, flavoured milk, cordial and sweetened fruit juices). Instead, give your child water to drink and foods that you’ve mostly prepared at home.

A dietitian can also help by giving you information on healthy food choices and the appropriate amounts for your child’s age and stage of development.

Sticking to a healthy eating plan

With young children, it is relatively easy to influence and control their food intake and exercise. Praising and rewarding children (for example with a sticker chart) encourages them to continue to make healthy choices and keep them motivated.

As children start primary school and eventually move on to high school, they are increasingly subject to peer pressure and have access to a wider variety of food when outside the home. However, you can always encourage a healthy and responsible attitude towards food and exercise. For adolescents, this may include involving them in meal choice and preparation; praising their healthy food choices but limiting criticism of less healthy ones; and helping them gain confidence in managing other aspects of their life before they have to take charge of their weight.

Be a role model to your children

As a parent or caregiver, you can help everyone in your family make healthier food choices and be more active just by showing how it’s done. Having a family-focused approach can help children make sustainable lifestyle changes. Try activities that the whole family can do together, such as walking, swimming or playing ball at a local park.

How to talk to your child about their weight

In general, using positive and non-judgemental language is recommended when talking about weight and weight management. For example, talk about making better choices to get fit and healthy, as opposed to talking about getting thinner or losing weight. Try not to use terms such as ‘overweight’ or ‘obese’ when talking to your child. Health professionals should do the same. Remember that the goal is to improve your child’s health and wellbeing, rather than achieving a target body weight. The focus should be on health, not appearance.

Psychologists can help kids who are having trouble at school, socially or with their self-esteem, and give parents strategies on how best to encourage healthy behaviours. Family-based behavioural treatment can be effective in helping children achieve a healthy weight through a range of behavioural strategies. Your GP can refer your child to a psychologist if needed.

So, talk to your doctor if you are worried about your child’s weight. Making some lifestyle changes can benefit the whole family and improve everyone’s health.

References

1. Australian Government Department of Health; National Health and Medical Research Council (NHMRC). Summary guide for the management of overweight and obesity in primary care, 2013. https://nhmrc.gov.au/about-us/publications/clinical-practice-guidelines-management-overweight-and-obesity (accessed Oct 2018).
2. Obesity in children (revised November 2013). In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2018 Jul. https://tgldcdp.tg.org.au/ (accessed Oct 2018).
3. Australian Government; Australian Institute of Health and Welfare (AIHW). Australia’s health 2018. 4.10 Overweight and obesity. https://www.aihw.gov.au/getmedia/4b395076-f554-4818-9150-64ffe2fc3039/aihw-aus-221-chapter-4-10.pdf.aspx (accessed Oct 2018).
4. Royal Children’s Hospital Melbourne. Child growth learning resource. Overweight and obesity. https://www.rch.org.au/childgrowth/Overweight_and_obesity/ (accessed Oct 2018).
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