Childhood Obesity - The Facts and What We Can Do About It

Healthy Living

A doctor checking the heart of an obese child

Childhood obesity is a serious health problem. Many governments have tried to kerb the epidemic by banning junk food ads that target children or imposing sugar taxes but one in five American and Australian children are obese.

If we don’t change our lifestyles, we could see the first generation of people who live a shorter life than their parents because they were obese from an early age.

Parents can do their part and reduce the risk of their children suffering a lifetime of health problems.

How Serious is the Childhood Obesity Problem?

The World Health Organisation (WHO) defines obesity as excessive fat accumulation that may impair health.

It considers childhood obesity to be one of the most serious global health challenges of the 21st century. There were an estimated 124 million obese children and adolescents globally in 2016, a 10-fold rise in 40 years. Many countries have agreed to targets for halting the increase in childhood obesity and some have succeeded in levelling-off obesity rates but, in most places, the problem is growing.

One in five school-aged children in the US has obesity. According to a Centers for Disease Control and Prevention study, the prevalence of obesity has increased by nearly 20% in the 18 years to 2016 in children and teenagers.

In Australia, the numbers are just as serious with one in five children and adolescents considered being overweight or obese. The number of obese children has more than tripled in the ten years to 1995.  

How is Obesity Calculated?

The Body Mass Index (BMI) is widely used to calculate where a person’s weight falls in one of four categories – underweight, healthy weight, overweight and obese. Health professionals still use it 150 years after its introduction but it does have it limitations - critics say it doesn’t take into account different body types, builds and shapes. The WHO published statistics (based on BMI) in 2018 that found global obesity has tripled since 1975.

The Body Mass Index (BMI)

Around the world the BMI is used to calculate weight in adults and children. BMI is calculated in both imperial and metric. The two formulas are:  

Imperial BMI Formula

Weight (lbs) x 730 / height (in2)

Metric BMI Formula

Weight (kg) / height (m2)

The weight-to-height index uses a different method of calculation for adults and children. As children grow at different rates, we measure their BMI against children of the same age and gender. The result is a body mass percentile. If a child is in the 50th percentile, then half of all children of the same age have the same BMI or less. A child on the 80th percentile means 80% of all children of the same age have the same BMI or less so the child is at risk of being overweight.

According to the CDC, children who are above the 85th percentile and below the 95th percentile are overweight while children who are above the 95th percentile for people of the same age and sex are obese.

Causes of Obesity in Children

The simplistic view of the cause of childhood obesity is kids are consuming far more energy than they expend. The body stores this extra energy as fat. The real causes are more complex and nuanced than that, including:

  • An increase in food portion sizes

  • More families with both parents working leaves less time for after school sport

  • Marketing of junk foods to children and parents

  • Eating more meals away from home

  • Availability of high-calorie foods and drinks

  • Genetics

  • Metabolism

  • Poor quality sleep

  • An increase in amount of time spent in front of screens

Fast food with large amounts of saturated fat

Health Problems Linked to Obesity in Children

Excessive weight has the potential to impact on all parts of a child’s life now and in their future as adults. Children with obesity can suffer a range of physical health problems including:

  • High blood pressure

  • High cholesterol

  • Asthma and sleep apnea

  • Heartburn

  • Fatty liver disease and gallstones

  • Joint problems

  • Low-grade inflammation

Children with obesity can suffer psychological problems including:

  • Anxiety and depression

  • Low self-esteem and bullying

  • Self-harm

Future Health Risks

When obesity begins in childhood, rather than adulthood, people are at greater risk of a shortened lifespan because of disease and the high toll excess weight has on the body.

Obese Adults

Obese children are more likely to become obese adults. Multiple studies in the US have shown two-thirds of children in the highest BMI quartile stay in the highest quartile as young adults. Getting weight under control in childhood means they are less likely to be overweight adults who may suffer from serious health problems.  

Chronic Disease

Children with obesity have increased risk of suffering from a chronic disease at an earlier age than someone in the healthy weight range. Research has found childhood obesity causes premature vascular aging and heart disease.

Being overweight can cause insulin resistance (pre-diabetes) and Type 2 diabetes can follow. Researchers have linked some cancers such post-menopausal breast, bowel, pancreatic, liver, upper stomach, gallbladder and thyroid have been linked to obesity. A large UK study also found some links between obesity and leukaemia, multiple myeloma and non-Hodgkin lymphoma in both men and women.  The longer a person is obese, the greater the chance they will develop a chronic disease but more research is needed to find the preventative effect of intentional weight loss.  

Pressure on Body’s Organs

Obesity can place several human organs at risk. The most obvious is the heart because it may need to work much harder in an obese person than it does in someone who is a healthy weight range. Years of strain can lead to blockages in the veins or the heart.  

Reducing the Chance of Childhood Obesity

For some children obesity is difficult to avoid due to the genetic lottery. If parents are obese, it’s more likely their children will be too.

However, genes don’t explain the increase in population rates of overweight and obese children. For many children, their environment is the main factor contributing to their obesity.

By changing what children eat and how they spend their time, parents can reduce the likelihood of their child being obese.

Increase Exercise

A sedentary lifestyle is one of the major causes of obesity. The less humans move, the more likely they won’t burn the calories consumed.

The Physical Activity Guidelines for Americans recommends children over the age of six do at least 60 minutes of physical activity every day. Make after school a time where your child takes part in a team or individual sporting activity at least one night a week and on the weekend. You may need to try a few different activities before they find one they like. On other days encourage kids to do unstructured physical activities they enjoy like walking the dog or playing at the park.

These activities also give you valuable time to connect with your children. Model good exercise habits so they realise it’s a normal daily activity. Try to walk part or all of the way to and from school to increase the amount of regular exercise the family has.

Any kind of movement is better than sitting. Make it fun by recording the number of steps each person in the family does each day then add up the tallies at the end of the week to see who did the most.     

Two children sitting on the couch playing video games

Decrease Screen Time

iPads, Playstations and Xbox have taken the place of a bat and ball for many kids around the world. Some kids are sedentary for most of their waking hours with much of this time spent looking at a screen and being disengaged from others. In a scientific statement by the American Heart Association, it links sedentary behaviour to the amount of screen time children have.

The American Academy of Pediatrics (AAP), give the following guidelines for the amount of screen time children should have:

  • Children under 18 months should avoid screen time completely

  • Between 18 months and 2 years children can watch or use high-quality programs or apps if adults are with them to ensure the child understands what they’re seeing

  • Children aged 2-5 years should have no more than one hour of screen time per day with adults watching or playing with them

  • Children aged 6 years and older should have consistent limits on the time they spend on electronic media.

In Australia, the screen time recommendation is no more than two hours per day for all children over the age of five. They do not recommend any screen time for children under two years of age.

To help with monitoring screen time you can create a Family Media Plan and access a Media Time Calculator provided by the AAP. Try to model good behaviour by putting down your phone as much as possible when you are with the kids. They are always watching what you are doing. Tell them you are putting down your phone and going outside for some fresh air or making a healthier choice on how you will spend your leisure time.  

Choose Healthy Foods and Drinks

Our children’s diets have changed over the years. They eat far fewer whole foods than their parents and enjoy far more processed foods high in calories and low in nutrients. According to the US NCBI, in 1977 snacks accounted for 18% of the total energy consumption of children aged six to 11 years of age. By 1996 snacks energy consumption had increased to 24% of their diet. Marketing processed foods has increased since the 1990s and governments worldwide are looking at advertising to children. Parents and health advocates have called for big food and drink companies to stop pushing the billion dollar industry of junk food options on to children.    

A young girl consuming fast food and a milkshake

You can offer healthy snack options like fruit, yoghurt and home-baked goods rather than processed snack foods loaded with fat and sugar. Be careful that your child isn’t filling up on snacks throughout the day to where they aren’t eating their more nutritious lunch and dinner.  

Try to follow the 2015-2020 Dietary Guidelines for Americans to ensure you are providing a nutrient-packed diet that contains a variety of vegetables, fruits, whole grains, lean protein, and low fat dairy.

Foods consumed away from the home are more likely to be higher in fat and sugar than meals you prepare and eat at home. Try to reduce the number of takeaway and restaurant meals your children consume by eating at home as often as possible. You and your children need not feel you are missing out on eating your favourite foods. There are healthier substitute takeaway meals you can make at home that are still tasty without the kilojoule overload. Check out these homemade meals of pizza, fish and chips and burgers and chips that are sure to be a hit with the kids.

Offer water to drink rather than orange juice, cordial, sports drinks and cool drink that are empty calories kids don’t need.  

Help for Parents

If you have concerns about your child’s weight, see your GP or pediatrician for an assessment and advice.  

Tammy George

Please note: Tammy's blog is general advice only. For further information on this topic please consult your healthcare professional.

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