The stimulus piece

Health psychologists are interested in what is called the obesogenic environment - that is, the combination of environmental and biological factors that promote obesity in individuals or populations.  The environmental factors include the physical neighbourhood environment, media and advertising, food tax policies, access to health care and the home environment. The home environment and parenting can influence a child's health by shaping dietary and physical behaviours, such as providing access to fruits and vegetables or encouraging kids to play outside.

In this case study, Østbye and his team examined the relationship between the home environment and behaviours related to obesity -- dietary and exercise habits -- among preschoolers. The study was carried out in North Carolina from 2007 to 2011. Women were recruited from a previous study of overweight and obese women, also carried out by Østbye. In order to be in the study, the women had to have someone living in their home who shared parenting responsibilities (i.e., a “partner”).

The researchers studied data from 190 children, ages two to five, whose mothers were overweight or obese. They collected information from the mothers on the children's food intake, with foods rated as healthy or “junk food.”  To gauge their levels of physical activity, the children wore accelerometers for a week, which measured moderate to vigorous physical activity as well as sedentary time.

The mothers were asked to fill in a questionnaire which asked about family policies around food and physical activity, accessibility of healthy versus junk foods, availability of physical activity equipment, and whether they model healthy eating or exercise for their kids.

The researchers looked at socioeconomic factors of the mothers, including their education levels and whether they worked, to see if this had an effect on the children's behaviours. The mother's socioeconomic factors did not affect their kids' physical activity but had mixed results when it came to their dietary habits. Among children of mothers with no college education and not working, limiting access to unhealthy foods and role modelling reduced 'junk' food intake scores whereas parental policies supporting family meals increased 'junk' food intake scores.  Overall, the home environment had more influence on the children's dietary habits than on their physical activity levels.

Østbye, T, R Malhotra, M Stroo, C Lovelady, R Brouwer, N Zucker, B Fuemmeler. The effect of the home environment on physical activity and dietary intake in preschool children. International Journal of Obesity, 2013; DOI: 10.1038/ijo.2013.76