The statistics are alarming: 21.5 per cent of Canadian preschoolers between the ages of two and five are overweight or obese. Being overweight as a young child increases the risk of being overweight at all other stages of life along with associated health problems. Kathryn Walton, a PhD student in the Department of Family Relations and Applied Nutrition, says some children are already showing signs of early heart disease or type 2 diabetes.
She notes that when it comes to families with preschool children, it’s the parents – not the kids – who decide which foods to buy and serve, or whether they will play at the park or stay inside watching TV. “The home environment can either assist or impede healthy lifestyles,” says Walton. That’s why she believes “it is important to educate and assist parents in providing healthy environments for their children to grow up in.”
For her master’s research, Walton decided to look at the effects of parenting stress on the weight of young children. “Stress, especially ongoing stress, causes the body to release a hormone called cortisol,” she explains. “We know from past research that high levels of cortisol will change the body’s metabolism, encourage the person to eat more, especially foods high in fat, and tend to decrease physical activity. So stress is often associated with weight gain in adults. We are not sure what effect this stress has on children.”
To study this question, Walton used some secondary data from a study done by her advisor, Prof. Jess Haines, who developed a parenting group in Boston called “Parents and Tots Together.” This nine-week course taught parents about general parenting, healthy eating, physical activity and sleep, and also surveyed them about other aspects of their lives.
For Walton’s research, she reviewed the participants’ responses on the parenting stress index scale, which measures the parents’ emotional reactions to some of the challenges of raising children. Her hypothesis was that parents who scored higher would be more likely to have children who were overweight or obese and who engaged in unhealthy behaviours, such as being sedentary, eating a poor diet and not getting enough sleep.
Participants indicated how much they agreed or disagreed with 12 statements, such as “I find myself giving up more of my life to meet the needs of my child than I ever expected,” and “Having a child has caused more problems with my partner than I expected.”
“Based on the results, we could classify about 20 per cent of the parents as experiencing high parenting stress,” says Walton. The parents involved in this group were from a high-risk population, so when the researchers measured the height and weight of the children, they found that approximately 48 per cent were overweight or obese – more than double the number in the Canadian population of preschoolers.
Surprisingly, though, Walton found no connection between children being overweight or obese and parenting stress. However, high levels of parenting stress did seem to be connected to children being less likely to have 60 minutes or more of active play each day during the week, and to parents being less likely to restrict TV time. The children in this group watched an average of four hours of TV per day, more than double the maximum amount recommended for the preschool age group.
It’s possible that the presence of risk factors, such as insufficient active play and less-restricted TV watching may lead to weight problems as children grow older, says Walton. She also points out that her study only examined one type of stress – the stress related to being a parent – and it is possible that other causes were more significant, such as financial or marital difficulties.
“It’s also possible that the majority of parents were able to prevent their stress from disrupting their ability to provide a healthy home environment for their children,” she adds.
Walton’s interest in human nutrition started young: “I was always curious about food and cooking and why people eat what they eat,” she says. As a teen growing up on a farm near Embro, Ont., she naturally rebelled a little against the idea of attending the University of Guelph, since nine members of her family were alumni and constantly urging her to apply.
“To humour them, I agreed to go on a tour,” she says. “Once I saw the campus, though, I realized it was where I wanted to be.” She completed her undergrad and master’s at U of G and was then accepted to a dietetic internship at Sunnybrook Health Sciences and Women’s College Hospital. Her experience there – she had the opportunity to work with dietitians in many areas of the hospital – qualified her to become a registered dietitian. With that extra qualification added to her credentials, Walton will begin her PhD work this fall.
She plans to continue researching the issue of overweight and obese children. “At the childcare centre on campus, we now have a dining room with one-way glass that allows us to observe families eating meals with their young children. We’ll be able to see the interactions and learn what influences how children eat. I’m excited to work with this setting – I believe it is the first of its kind in Canada.”