Is food insecurity a predictor of childhood obesity?

In a systematic review, a link between food insecurity (ie, low or very low food security) and obesity or greater weight gain was observed in early childhood. Some studies have pointed to an association specifically in girls and in children experiencing food insecurity at multiple timepoints.

“Addressing food insecurity while promoting healthy body weights among children is a major public health challenge,” said the researchers. “Deeper understanding of the nuances of [the associations between food insecurity and obesity] is critically needed to effectively intervene against childhood obesity.”

“We focused on obesity rather than both overweight and obesity because obesity has a greater sensitivity and specificity for identifying excess body fat and carries a higher risk for adverse health outcomes,” they continued.

The researchers included 13 studies to evaluate longitudinal associations between food insecurity and obesity in US children aged 1–19 years. Of these, five directly looked into the association between food insecurity and obesity, 12 investigated its correlation with BMI or BMI z-score, while three evaluated multiple outcomes. [Pediatrics 2022;150:e2021055571]

 

Food insecurity and higher BMI

Among the studies that used ECLS-K* data, two saw higher BMI increases for girls from food-insecure households. [J Hunger Environ Nutr 2016;11:227-241, J Nutr 2005;135:2831-2839] One of these studies also showed a greater BMI increase in children whose households were food insecure at two timepoints. Another study found lower BMI gains in children whose households transitioned from food secure (ie, high or marginal food security) to insecure across two timepoints. [Pediatr Obes 2021;16:e12762]

 

Food insecurity and higher BMI z-score

Two studies found associations between food insecurity and a higher BMI z-score in either infancy or early childhood. [Pediatrics 2020;146:e20193725; J Acad Nutr Diet 2012;112:1949-1958] These were supported by one study showing an association between food insecurity in the first grade and higher BMI z-score in the third grade. [Nutrition 2018;51-52:1-5] However, in another study, the association was only seen at a later timepoint (between food insecurity in the fifth grade and a higher BMI z-score in the eighth grade). [Int J Epidemiol 2020;49:519-527]

Another study found an association between food insecurity and higher BMI z-score, but only among girls. [Soc Sci Med 2017;181:168-176] According to the researchers, factors driving this association could include different feeding practices by parents or different responses to stress. “Household stress may play an important mediating role in the relationship between food insecurity and weight outcomes.”

 

The pandemic factor

During the first year of the COVID-19 outbreak, food insecurity among US households with children jumped up a notch from the previous year (from 13.6 percent to 14.8 percent). [www.ers.usda.gov/publications/pub-details/?pubid=102075, accessed September 8, 2022] “[This was also] a reversal of the declining trend observed over the previous decade,” said the researchers.

“The increases in food insecurity and accelerated weight gain observed among children during the COVID-19 pandemic indicate that greater understanding of how these two issues interact is of great importance for child health, particularly in terms of associations between food insecurity episodes and weight status over the long term,” they continued.

 

A public health priority

While their data did not allow for drawing broad conclusions, the researchers noted that these could help identify directions for further research. “[Further] studies need to consider interactions between food insecurity and salient demographics and the broader context of the household environment to enable us to meet the dual challenges of reducing childhood obesity and ensuring food security for all families.”

“Irrespective of any future conclusive evidence on the relationship mechanisms between food insecurity and childhood obesity … effective interventions against child food insecurity should be a public health priority to promote the physical, emotional, and cognitive wellbeing of children and parents,” they said.

They also called for further studies that would evaluate the associations in adolescence and early adulthood to help shed light on the differences in the links between food insecurity and weight by sex, given evidence showing a higher prevalence of food insecurity among women with greater adiposity.