Are low-income kids at greater risk for obesity?

Children from low-income families are 3 times more likely to be obese than children raised in higher income households, according to a report from the United Kingdom.

The study used data from more than 11,000 children and investigated family income, maternal health behaviors, children’s physical activity, sedentary behaviors, and diet.

Researchers found that children in the lowest income bracket at age 5 years had a 2.0 increased relative risk of obesity and a 3.0 increased relative risk by age 11 years compared to children in the top income brackets.

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Researchers considered a number of maternal health behaviors in the prenatal and infant periods, including smoking during pregnancy, duration of breastfeeding, and when infants were introduced to solid foods. The study also reviewed physical activity levels, including frequency of exercise, active playing with a parent, hours watching television, time spent on a computer, frequency of playground use, weekday bedtimes, whether the child regularly ate breakfast, fruit consumption, sweet drinks consumption, and maternal body mass index (BMI).

In addition to tying increased obesity prevalence to children in lower-income households, the study also found that children from lower-income households were more likely to have mothers who smoked; were not breastfed or breastfed for only a short time; were introduced to solid foods earlier; and had mothers with higher BMIs. Children in lower-income households also were less likely to play sports, engage in active play with a parent, use playgrounds or ride bikes, spent more time watching television and playing on computers, ate less fruit and did not have regular breakfasts, and did not adhere to regular or early bedtime routines.

Children on the early end of the spectrum were a little better off, according to the study, with children in the 5-year-old study group having more physical activity and less risk of being overweight than the 11-year-olds.

The study notes that in examining the risk factors for obesity across the cohort, income was not a prominent risk factor among 5-year-olds, but it was in the 11-year-old group.

The study authors also investigated trends that led to weight gain in children who were not overweight at age 5 years, but added weight by age 11 years. Research revealed that earlier bedtimes, and increased fruit consumption worked against weight gain, while maternal smoking and early introduction to solid foods were noted to contribute to weight gain over the years.

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“We show, consistent with prior studies, stark income inequalities in the risk of obesity throughout childhood, the emergence of inequalities in the risk of overweight by age 11 years and that inequalities became more pronounced between age 5 and 11 years,” according to the report. “Multiple family health behaviors and environmental risk factors were relevant when attempting to explain income inequalities in overweight and obesity amongst children. The results suggest that both markers of physical activity and diet at ages 5 and 11 years were particularly relevant in attenuating inequalities throughout childhood. However, maternal health behaviors in early childhood were relevant too as on their own in the model, they attenuated inequalities in child obesity between the bottom and top income quintiles by around 20%.”

The effect of some risk factors was different at various stages, for example skipping breakfast and fruit consumption contributed to weight gain at age 5 years, but had little impact at age 11 years, according to the report. Additionally, playing sports more than 3 times a week had a larger impact on weight at age 11 years than at age 5 years.

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The revelation that children in low-income households were more likely to gain weight throughout their childhood suggest that more efforts be made to offer early interventions for disadvantaged children, according to the report. Such interventions may include educating parents about not smoking during pregnancy and the importance of earlier bedtimes.

“Greater efforts are needed to investigate which interventions might contribute to reduce the prevalence of child overweight and obesity. In particular, more research and evaluations are needed to understand which changes in family and children’s routines might contribute to a reduction in socioeconomic inequalities in children’s adiposity at different ages and their widening across childhood,” according to the report. “Based on the findings of this study, interventions focusing on family physical activity and ‘healthier diets’ could be of benefit, for instance these could include family sport days, distribution of gym passes and cookery classes.”

Although the study focused on children in the United Kingdom, its data is applicable to children in the United States.

Roughly 17% of children and adolescents aged 2 to 19 years in the United States are now obese-accounting for more than 12.7 million individuals, according to the Centers for Disease Control and Prevention (CDC). Prevalence is higher among Hispanics and blacks, in households where the adults have been poorly educated. The CDC says obesity levels of children in households whose head of the house completed college were half that of those who head of the household did not complete high school. Poverty is also a factor, notes CDC, revealing that obesity prevalence in young children was highest in families living at or below the poverty threshold.

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Increased obesity prevalence among children in low-income households is a result of several factors, according to the non-profit Obesity Action Coalition (OAC). These children are not always able to participate in extracurricular activities-leading to decreased physical activity; parents may rely on convenience foods high in calories, fat, and sugar to feed their children; and parents with little to no education may not have the best information on proper nutrition and healthy food choices to implement within their households or pass on to their children, according to OAC.

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Stephen Cook, MD, MPH, FAAP, FTOS, a child obesity expert at the Golisano Children’s Hospital at the University of Rochester Medical Center in Rochester, New York, says the UK study is not surprising, and obesity associated with low income has also been described in both US adults and children.

“The big concerns we have are the access to affordable, healthy food. Poor neighborhoods typically have higher density of fast food outlets, and even the small corner stores or grocery stores don't have many healthy options,” Cook says. “They also don't have many larger supermarkets that can competitively price healthier foods at a lower price. Families in poorer neighborhood also have a lot more concerns of safety in their neighborhoods. Even if their crime rates are not as high, the perception of lack of safety is also high, either from crime, drug activity as well as traffic and walkability.”

Cook also noted the study’s observation of the link between maternal behaviors such as poor eating habits in pregnancy and smoking and childhood obesity.

“For practicing pediatricians, I hope it helps us to stop and think a second more about what the parent’s health and lifestyle behaviors are like also. When thinking of preventing obesity or treating a child with obesity, we have to include the parents, they have to want to be on board and motivated for change,” Cook says. “We are also 'treating' the family. So advice and recommendations for getting more activity, cutting back on screen time, and improving eating patterns, has to apply to everyone in the house, including the parents.”