Children from low socioeconomic backgrounds are already more likely to be overweight by age four than median income families, but the differences become much more marked as childhood progresses, a new Australian study has found.
People who are overweight or obese in childhood are more likely to suffer health problems as adults and are then unlikely to return to healthy weight without significant intervention, experts have said.
The new study, conducted by the Murdoch Children’s Institute and published in the journal PLOS One, examined data on 4949 children from the Longitudinal Study of Australian Children. Body Mass Index (BMI) was measured at age four to five starting in 2004 and again every two years until 2010.
The researchers compared BMI with data on the study participants' family and neighbourhood socioeconomic status and found that disadvantaged kids were much more likely to be overweight.
“We showed that socioeconomic differences in high BMI already present at age 4-5 years not only persisted but had more than doubled by age 10-11 years,” the researchers said in their paper.
However, lead researcher Professor Melissa Wake, paediatrician and professor at the Murdoch Childrens Research Institute and Royal Children’s Hospital, said these differences were not just confined to the most disadvantaged.
“There was a stepwise gradient in risk, such that children in each quintile further from the most advantaged fifth were progressively more likely to be on a heavier growth pathway from early childhood,” she said.
The researchers said that childhood has become the critical period when socioeconomic inequalities in overweight emerge and strengthen.
“Although targeting disadvantaged children with early overweight must be a top priority, the presence of childhood overweight even among less-disadvantaged families suggests only whole-society approaches will eliminate overweight-associated morbidity,” the researchers wrote in their paper.
Wake up call
Melanie Nichols, a Public Health Research Fellow at Deakin University, said the study reiterated the fact that overweight and obesity are unevenly distributed in Australian society.
“It is a real wake up call, however, that inequalities in obesity prevalence are so stark among such young children. We must do more to support all families to make healthy choices,” said Dr Nichols, who was not involved in the study.
“Only a very small percentage of children who had been overweight returned to a healthier weight status, which really emphasises the importance of primary prevention to keep children healthy. We need to be thinking big picture about creating health promoting public policy and comprehensive, whole of community primary prevention approaches to address obesity in all age groups and all socioeconomic backgrounds.”
Louise Baur, a professor of paediatrics at the University of Sydney said the findings highlight how early the link between obesity and social disadvantage occurs.
“Disturbingly, the social gradient linked to obesity at age 4-5 years, where obesity was more prevalent in socially disadvantaged children, was even more pronounced at age 10-11 years,” said Professor Baur, who was not involved in the study.
“In clinical practice – clinicians working with patients and families living in socially disadvantaged areas, or who experience social disadvantage, should be particularly aware of their higher risk of obesity and obesity-related health problems and the extra support that may be required.”
Pathologising poor families?
However, Darren Powell, a doctoral candidate in Health and Physical Education at Charles Sturt University, said that “the problem with this sort of study is its reliance on BMI.”
“BMI is a highly contested measure, particularly so when measuring children’s fatness and comparing it a ‘normal’ or ‘healthy’ weight. Using BMI as a measure of health is even more problematic, given the research that questions the whole notion that being fat or obese or overweight is inherently unhealthy,” he said.
“My other concern is with the authors' recommendation to target overweight children with a low socioeconomic background. Again poor people and poor families are opened up to further interventions because they are assumed to be unable to make (or be responsible enough) to make the ‘right’ choices, live the ‘right’ lifestyle, or weigh the ‘right’ number of kilograms for their height.”
Mr Powell said that while it is critical to look at health inequalities that are associated with poverty, “I worry that this sort of research and interventions that spawn from it may further stigmatise fat people and effectively pathologise poor families, neither of which address the wider determinants of ill-health and poverty.”