2026 Theses Doctoral

The Relationship Between Food Insecurity and Ultra-Processed Food Intake Among U.S. Children Aged 5–12 Years: Evidence from NHANES 2001-2023

Kahwaji, Sandra H.

Ultra-processed foods (UPFs) contribute a significant portion of total energy intake in the United States, particularly among children from low-income and racially/ethnically marginalized households. While UPF consumption has been linked to lower diet quality and adverse health outcomes, few studies have examined how food insecurity and federal nutrition assistance program participation (FNAP) influence UPF intake among U.S. school-aged children. Despite its implications for long-term health disparities, this intersection remains understudied.

This dissertation examined associations between food security status and UPF consumption among U.S. children aged 5–12 years using nationally representative data from the National Health and Nutrition Examination Survey (NHANES) (2001–2023). The study had three aims:

Aim 1: To examine the association between food security status and UPF consumption among U.S. children aged 5–12 years.
Aim 2: To examine whether participation in FNAP modifies the association between food security status and UPF consumption.
Exploratory Aim 3: To examine temporal trends in UPF consumption among U.S. children aged 5–12 years.

UPF intake was classified using the Nova system and measured as percent energy from UPFs (% kcal) and percent grams from UPFs (% grams). Food security was assessed using the U.S. Food Security Survey Module. Survey-weighted multivariable regression models were conducted to estimate associations between food security status and UPF intake, assess effect modification by sociodemographic characteristics and FNAP participation, and examine temporal trends while accounting for the complex NHANES sampling design.

A total of 13,850 children met the inclusion criteria of having at least one complete, reliable 24-hour dietary recall, no missing UPF data, and no missing food security data. A major finding based on the descriptive statistics is that UPFs accounted for approximately two-thirds (66%) of total energy intake among U.S. children aged 5–12 years.

Aim 1 Results: First, food insecurity was associated with a higher percentage of energy intake from UPFs (+1.9 percentage points), in models adjusting for sociodemographic and NHANES survey cycle. Second, there was a positive association between food insecurity and percent energy from UPFs observed among Non-Hispanic White children and, to a lesser extent, Non-Hispanic Black children, whereas no clear association was observed among Hispanic children. Third, when 10 subgroups of UPF were analyzed, food insecure children had higher energy contributions from ready-to-eat/ready-to-heat mixed dishes and industrial grain products. Fourth, higher Healthy Eating Index-2020 (HEI-2020) scores were associated with lower UPF consumption, and when the models were adjusted for HEI-2020 scores the UPF to food security relationship remained significant.
Aim 2 Results: First, FNAP participation modified the association between UPF and food security status, with differences in both the magnitude and direction across food security groups. Second, age and Poverty Income Ratio (PIR) further modified this relationship. Stronger associations were observed among food-insecure children participating in FNAP, particularly those aged 8–10 years and those with lower PIR. However, the highest UPF intake was observed among food-insecure children who did not participate in FNAP and had lower PIR.
Exploratory Aim 3 Results: The temporal analyses of UPF consumption showed that intake increased from 2001–2008 to 2009–2016 and declined modestly in 2017–2023. However, changes in the UPF subgroups consumption were more evident than changes in overall intake, with increases in some subgroups and declines in others. Four subgroups increased over time: industrial grain foods, sweet snacks & desserts, ready-to-eat/ready-to-heat mixed dishes, and savory snacks. Whereas four subgroups decreased over time: sugar sweetened beverages, flavored dairy products, potato products, and other UPF decreased. Changes in UPF intake following the 2013 revision of school meal standards were similar among National School Lunch Program participants and non-participants.
In summary, findings suggest that while food insecurity is associated with small differences in UPF intake, children’s high reliance on UPFs appears to reflect broader structural characteristics of the U.S. food environment rather than food security status alone. The relationship between food insecurity, UPF consumption, and FNAP appears complex and needs further research. These findings highlight the need for policies and interventions to address both food insecurity and the broader food system factors that influence children’s dietary patterns.