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The team behind a NSW longitudinal study examining the link between poor diet in early childhood and obesity and tooth decay says tackling such problems demand an integrated policy approach. By Kathy Graham
At school entry age, around one quarter of Australian children are overweight or obese and around 40 per cent already have tooth decay. Both these conditions negatively impact children, their families, and the healthcare system and often persist into adulthood. Which is why Amit Arora, Associate Professor in Public Health at Western Sydney University, started the Healthy Smiles Healthy Kids study in 2010, in collaboration with the former Sydney South West Area Health Service, investigating infant and young children feeding patterns and their links with obesity and tooth decay in early childhood.
In what has since become a multi-institutional collaboration, A/Prof Arora’s team is examining longitudinal data from 1035 infants in Greater Western Sydney, recruited six to eight weeks after their birth.
A/Prof Arora explains that the process of data collection started when the children were aged two months, then continued at four and eight months, followed by 1-2 years, 3-4 years, and then 7-9 years of age. More data will be collected when the children are 12-13 years old.
Although there is global evidence of the link between obesity and tooth decay as they share common risk factors such as diet, A/Prof Arora says that “a better understanding of the diet trajectories of healthy and unhealthy foods in early life and their impact on subsequent obesity and tooth decay will help guide prevention strategies and policy changes”.
So what has the data revealed so far?
Twelve per cent of infants received ‘core’ foods before 17 weeks of age. Core foods (such as fruits and vegetables) are essential to meet an infant’s increasing nutritional and developmental needs, but the team observed many children started consuming them too early. “Before 17 weeks is very concerning as Australian Infant Feeding Guidelines recommend introduction of such foods at around six months of age, and that mothers should exclusively breastfeed their baby until then,” says A/Prof Arora. “There is a lot of global evidence that children who start solid foods before 17 weeks are at an increased risk of developing obesity, allergies and other adverse health outcomes.”
A/Prof Arora explains that when they interviewed mothers about why they started solid foods early, the main responses were that breastfeeding was too difficult, mums had to return to work, and they felt their child wasn’t satisfied by breast milk alone. “Health professionals need to continue to get the message across to the community on the benefits of breastfeeding,” A/Prof Arora says. “Moreover, women at risk of stopping breastfeeding early need additional support.”
‘Discretionary’ foods (e.g. foods high in sugar, fat or salt) are considered unhealthy and do not have a high nutritional value. Current Australian recommendations state that these should be avoided in the first year of life. Yet worryingly A/Prof Arora and his team found when they analysed the data that a whopping 95.3 per cent of infants were given such foods before they were one year old. “We also found that family’s socioeconomic status (SES) was a key factor. So those who were at a social disadvantage were almost four times more likely to introduce discretionary foods before the recommended age than those who weren’t. This is very concerning as this puts infants at risk for developing obesity and tooth decay in later years.”
Dr Narendar Manohar, a PhD student under A/Prof Arora’s supervision, and Prof Andrew Haven, examined the dietary patterns of children at 4, 8, 12, 24 and 36 months of age.
“We observed that intake of core foods increased rapidly in the first year of life, followed by a decline in the frequency of intake after age two years, whereas the intake of discretionary foods progressively increased from the time of introduction until age three years,” Dr Manohar says.
The team also found that children who continued to be high consumers of discretionary foods from an early age were twice as likely to be overweight or obese later on.
Mum’s education, country of birth, being a single parent, having three or more children, and low SES significantly contributed to the child’s dietary intake trajectories.
Low SES had an equally profound effect on both obesity and dental decay in early childhood. “So if you were socioeconomically disadvantaged, you were three times more likely to be overweight or obese and to have dental caries,” says Dr Manohar.
“What we found was discretionary food patterns were linked with being overweight and obese. Breastfeeding beyond 12 months was linked with caries. And socio-economic disadvantage was linked with both.”
When the team interviewed mothers to better understand their diet related decisions for their children, they found many lacked nutrition-related knowledge. “Some parents don’t realise the amount of sugar in a glass of fruit juice,” says A/Prof Arora. “And many don’t know how to read and understand nutrition labels on packaging.”
They also found that children’s diets are influenced by what parents and siblings consume, the child’s preferences and demands, availability of food in households, how much time parents have to prepare healthy meals and snacks, and media advertising.
Here education is paramount. “But rather than telling the parents what is required, we need to work with them to develop health promotion programs that best suit their needs,” says A/Prof Arora.
“We’ve been able to show that unhealthy dietary patterns start early, and the consumption continues to increase into early childhood, highlighting the importance of establishing healthy patterns early in life. What we need now is a collaborative approach where dental and medical professionals, the food industry, and policy makers work together with families to promote healthier age-appropriate alternatives for their children and themselves.”