Australian children as young as two years old are obese, but many of the health effects associated with the condition don’t emerge until the adolescent years, according to new research by Murdoch Childrens Research Institute.
The study, which looked at the morbidity patterns in over 16,300 normal weight, underweight, overweight and obese children between the ages of two and 18, found that relationships between poor health and weight status vary greatly by age group.
Amongst toddlers and pre-schoolers, poorer overall health was most common in the underweight group. But things reversed for older children, with poorer health most common in the obese. Weight category had little impact on physical health in two to five year olds, but between ages six to 18 years obese children and adolescents experienced markedly poorer overall health.
Prevalence rates of obesity were similar across all age ranges, affecting around 20 to 25 per cent of children at all ages. The study also found five per cent of children were underweight at all ages measured.
The prevalence of underweight was highest in the toddlers (5.3%) and lowest in the teenagers (4.6%) whereas, conversely, obesity was most prevalent in teenagers (6.1%) and least prevalent in toddlers (4.4%). Surprisingly, underweight school-aged children and adolescents were physically among the healthiest in their age groups, while normal-weight children tended to experience the best psychosocial and mental health outcomes.
Lead researcher Professor Melissa Wake said the study confirms previous findings that obese children experience lower health related quality of life than their normal-weight peers, but demonstrates that this association is weak or absent in very young children, emerges convincingly only in the school years, and then steadily strengthens with age.
“Our findings are consistent with research that shows overweight and obese older children and adolescents report poorer global health, more primary health-care needs and higher prevalence of wheeze and asthma than children of normal weight.”
“Importantly, what it also highlights is this period of time between the early onset of obesity – when young children don’t really feel its full health-related effects – and adolescence, when obesity really starts to bite. The positive flip-side of this is that doctors and researchers have a really long window to intervene.”
Researchers say the study highlights the need for effective obesity prevention strategies throughout childhood and adolescence.