The data showed strong associations between certain behavioral factors and likelihood of childhood obesity, such as late or irregular bedtimes and a mother's smoking habit during pregnancy.
Being poor doesn’t just increase a child’s chances of becoming obese. The risk rises with each passing year, according to a study from the United Kingdom that identified specific dietary and behavioral reasons this phenomenon occurs.
The research, published in the European Journal of Public Health, found that things like a mother’s greater likelihood to smoke, late or irregular bedtimes, and skipping breakfast were all associated with greater likelihood of childhood obesity.
The trends take hold early and get worse quickly; the poorest 5-year-olds were twice as likely to be obese as the wealthiest, but by age 11 the poorest were three times as likely to be obese as their well-off counterparts.
Use of data from the Millennium Cohort Study, a sample of the population drawn from all live births from September 2000 to January 2002, allowed researchers to tap into behavior of both mothers and children, to see what behaviors had the greatest associations with childhood obesity. Mothers’ high body mass index (BMI) was very strongly associated with childhood obesity, but researchers noted this could be for genetic reasons as well as dietary and lifestyle factors, and they sought to tease this out in their analysis.
Another behavioral factor strongly associated with childhood obesity was the mother’s smoking during pregnancy.
The fact that maternal health was such a strong influence on early childhood showed researchers that keys to halting childhood obesity would be found early in life, even though some markers were less relevant by age 11.
“For example, skipping breakfast was related to the risk of overweight and obesity, and fruit consumption was related to risk of overweight at age 5, but these factors played a rather minor role at age 11,” they wrote. “In contracts, sports more than 3 time a week played a more important and protective role at age 11 than age 5.”
Because the magnitude of behavioral effects increased between age 5 and 11, the researchers suggested that interventions should start early, because they would help children develop healthy habits. Researcher mentioned British programs, but they are akin to the “Let’s Move” initiative that calls for getting children to get more exercise.
A limitation of the study noted by the authors was the inability to allow for a conclusion regarding why risk factors and income inequality might cause children to be overweight or obese. The researchers called for more work to show what would happen if risk factors were reduced among low-income families.
Goisis A, Sacker A, Kelly Y. Why are poor children at higher risk of obesity and overweight? A UK cohort study [published online December 10, 2015]. Euro J Pub Aff. 2015. doi: 10.1093/eurpub/ckv219.