Weight gain and obesity occur when the energy we get from food and drinks is greater than the energy we burn up through physical activity, growing and other body processes. A build up of energy in the body is stored as fat.
In other words, weight gain occurs over time when the ‘energy in’ is greater than ‘energy out’.
Over the last 25 years, rates of obesity have risen in many countries around the world. Some researchers have called it an “international epidemic of childhood obesity”.
In the ten-year period from 1985 to 1995, national surveys showed that the combined number of Australian children who were overweight or obese more than doubled.
In addition, the level of obesity tripled in all age groups – and for both boys and girls – over the same period. In comparison with other times in Australia’s history, the increase in the rates of overweight and obese children between 1985 and 1995 were extremely rapid.
In a major study in 2004, almost 5,500 school-aged students in years K, 2, 4, 6, 8, 10 were surveyed as part of the NSW Schools Physical Activity and Nutrition Survey (SPANS). Similar to national survey findings, the results from SPANS showed that the number of NSW children who were overweight or obese had risen from around one in 10 in 1985 to one in four in 2004.
The NSW Secondary Schools Health Behaviours (SSHB) Survey, involving over 7,000 students in Years 7-12 (SSHB), indicates some progress in dealing with the issue. The survey reports that there was no additional increase in the rates of childhood overweight and obesity in NSW among secondary school students between 2005 and 2008.
Tracking from childhood to adulthood
It is very important to prevent and manage obesity in children as there is a high risk that the problem will persist into adulthood. Obese children have a 25-50% per cent chance of being obese adults, however, this possibility can be as high as 78% for older obese adolescents.
Obese adults who were overweight as adolescents have a higher risk of weight-related ill health and early death than adults who became obese in adulthood.
Being overweight or obese puts a significant strain on our bodies and leads to many health problems in adults, such as muscle and bone complaints, cardiovascular disease, some types of cancer, sleep disorders, Type 2 diabetes and high blood pressure. Many of these health problems are preventable by leading a healthy lifestyle.
Once a child is overweight or obese, it is unlikely that he or she will return to a healthy weight without some deliberate, remedial action. If overweight or obese children do not attain a healthy weight, they are more likely to develop weight-related health problems when they become older.
Obese children and adolescents suffer from an increased range of medical conditions. For example, the rate of Type 2 diabetes is increasing in children and adolescents. Other problems include sleep disturbances, heat intolerance, breathlessness when active, tiredness and flat feet. Obese children, particularly older girls, also tend to have lower self esteem.