Infants in US households with very low food security face higher risk of obesity, finds study
While the reasons for the association between food insecurity and greater obesity risk are not yet understood, they may be related to poor nutrition and overfeeding, say experts
Food insecurity during infancy has been linked with overall poor health. However, a research team has now found that food insecurity in infancy is associated with obesity and being severely overweight. Led by a researcher at Johns Hopkins Bloomberg School of Public Health, the study reveals that infants from households reporting very low food security, a measure of access to adequate and healthy meals, tend to weigh more than those from households with relatively high food security.
The team, which also includes experts from the University of South Carolina, tracked over 660 infants in North Carolina over their first year of life, with regular interviews of the infants' mothers. They found that when mothers reported very low food security as per a standard government questionnaire, the infants were more likely to have above-average body mass indices (BMIs), higher fat levels and other measures indicating greater obesity.
Among infants from food-secure households (high and marginal food security), the percentage of infants at risk of being overweight decreased from 46.8% at 3 months to 33.1% at 12 months, whereas among infants from food-insecure households (low and very low food security), the percentage increased from 53.2% to 66.9% during that period.
The results suggest that household food insecurity may be especially hazardous for infants, given that diet and weight gain in infancy are thought to have a potentially large impact on the future risks of obesity and related health conditions, say experts.
According to the study, while the reasons for the association between food insecurity and higher obesity risk are not yet understood, they may be related to poor nutrition and overfeeding. They believe that larger and longer-term studies are needed to resolve the many questions about food insecurity and obesity, including whether the association in infancy continues into later childhood.
The experts emphasize that the findings are especially relevant today when there is such widespread food insecurity in the US due to the coronavirus pandemic. "During the Covid-19 pandemic, there have been a record number of families experiencing food insecurity. This research is especially relevant right now, because food insecurity may be contributing to rates of obesity in very young children. The health effects resulting from the Covid-19 pandemic will take years to fully explore, but increases in the numbers of children with obesity may be one of them," lead author Dr Sara Benjamin-Neelon, the Helaine and Sidney Lerner Professor in public health promotion in the Bloomberg School of Public Health, tells MEA WorldWide (MEAWW).
Dr Benjamin-Neelon, who is also an associate professor in the Bloomberg School’s Department of Health, Behavior, and Society, says that vulnerable families may be most impacted by the pandemic. "Many businesses, schools, and child care programs have closed, resulting in high rates of unemployment and increased poverty. More people, especially families with children, are experiencing food insecurity. Young children – including babies – who would typically have access to regular meals and snacks in schools and child care, are most at risk," she tells MEAWW.
Preventing food insecurity in young children in the US is an important public health goal because there are both immediate and long-term adverse health consequences, explain researchers. Infants may be especially vulnerable to food insecurity because infancy is a time of rapid growth.
Household food security is defined by the US Department of Agriculture as all members having readily available, nutritionally adequate, and safe foods at all times. An estimated 12% of households were food insecure in the US in 2017. That same year, nearly 3 million or about 8% of households included children who experienced food insecurity. “In a recent report by the US Department of Agriculture, it was estimated that nationally, 7.1% of food-insecure households had children aged 6 years and younger who experienced food insecurity in 2018,” state the findings published in Pediatrics.
In the current research, participants were from the Nurture Study, a birth cohort of 666 racially diverse women and their infants residing in the southeastern US. Most of the infants (68.6%) were African-American, 14.9% were White, and 55.4% of the households reported annual incomes below $20,000. Between 2013 and 2017, the authors enrolled pregnant women, reconsented them after delivery, and conducted home visits when infants were 3, 6, 9, and 12 months. Women completed questionnaires via telephone in months 1, 2, 4, 5, 7, 8, 10 and 11. The goal of the Nurture Study was to assess feeding, physical activity, sleep, and stress and associations with weight gain in infancy, exploring the role of food security.
The researchers compared the weight and length of infants in the study to a global population of healthy infants from eight counties to determine "at risk of overweight". They found that infants from households categorized as low and very low food security tended to move into this overweight risk category over the 3-month visit to the 12-month visit period (53.2% to 66.9%). On the other hand, infants from households with high and marginal food security — those with moderate access to adequate, healthy food — tended to move out of this category (46.8% to 33.1%) during the period.
The findings also reveal that infants in households with low and very low food security were generally more likely (1.72 and 1.55 times more likely) to be at risk of overweight. Additionally, infants from very low food security households were significantly heavier by comparison with infants from food-secure households and had more fat accumulation by standard caliper-based measures.
There are several potential explanations for the findings. One may relate to maternal feeding behaviors in the absence of an adequate supply of healthy foods, says the analysis. Some previous studies suggest that food insecurity may influence obesity and excess adiposity through inappropriate infant feeding practices and less healthy diets.
According to Dr Benjamin-Neelo, food insecurity is associated with lower quality diets that promote obesity, although infants, especially in the first six months of life, should be consuming limited foods, mainly just human breastmilk or infant formula. "Many people may believe that food insecurity is simply a lack of food. However, food insecurity includes insufficient access to healthy food as well. It is well-established that healthier foods like fruits and vegetables cost more than less healthy foods. But, what we feed babies may be just as important as how we feed babies," she says.
The author emphasizes that for all families, but especially those experiencing food insecurity, how they feed babies may be contributing to obesity. "Practices like propping up a bottle during feedings and encouraging babies to finish the bottle do not allow babies to stop eating when they are full. Adding cereal to the bottle is also a way to feed extra calories that may not be needed and could actually increase the risk for having obesity. A key recommendation for all parents and caregivers is to listen and watch carefully: feed babies when they are hungry and stop when they are full. And, breastfeeding is best, if possible, for both mothers and babies," Dr Benjamin-Neelon tells MEAWW.