A new study found that children whose parents have high levels of stress have a Body Mass Index (BMI), around 2 per cent higher than children of parents with low levels of stress.
The children with higher parental stress levels also gained weight at a rate 7 per cent higher than other children.
Although the figures sound low, according to lead author Dr. Ketan Shankardass, they are significant because they are happening in children, whose bodies, eating and exercise habits are still developing. If that weight gain continues and is compounded over their lifetime, it may lead to serious obesity and health issues.
Dr. Shankardass said he believes this is the first study to link parental stress to weight gain in such young children.
Childrens Health Study and Stress
The data studied by Dr. Shankardass, a social epidemiologist, was collected during the Children’s Health Study, one of the largest and most comprehensive investigations into the long-term effects of air pollution on the respiratory health of children.
The childrens' BMI was calculated each year. Parents filled out a questionnaire to measure their perceived psychological stress. They were asked how often in the last month they were able or unable to control important things in their life and whether things were going their way or their difficulties were piling up so high they could not overcome them.
It is not yet clear why the link between stress and obesity exists.
Dr. Shankardass theorises that parents may change their behavior when they are stressed, to reduce the amount of physical activity in the household or increase the amount of unhealthy food available.
Parental stress could also create stress for the children, who cope by eating more or exercising less, or whose stress leads to biological changes that cause weight gain, he said.
Focus on Intervention
Rather than focusing only on getting parents to change their behavior, Shankardass says, it would be more useful to focus on interventions that can support families living in challenging conditions, such as ensuring they have a consistent supply of healthy food, an opportunity to live in a nice neighbourhood and other financial or service resources to help cope with stress.
“Childhood is a time when we develop inter-connected habits related to how we deal with stress, how we eat and how active we are,” Dr. Shankardass said. “It’s a time when we might be doing irreversible damage or damage that is very hard to change later."
He noted that more than half the students followed in the California study were Hispanic, and that the effects of stress on their BMI was greater than children of other ethnic backgrounds. He said this was consistent with other research which has suggested that Hispanic children may be more likely to experience hypherphasia, which is excessive hunger or increased appetite, and sedentary lifestyle.
Further research should examine other reasons that Hispanic children are more susceptible to parental stress, including differences in how Hispanic parents respond to stress or how Hispanic children perceive stressors or cope with stress.
K. Shankardass, R. McConnell, M. Jerrett, C. Lam, J. Wolch, J. Milam, F. Gilliland, K. Berhane. Parental stress increases body mass index trajectory in pre-adolescents. Pediatric Obesity, 2013; DOI: 10.1111/j.2047-6310.2013.00208.x
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