The influence of food insecurity on reward neurobiology in children

Project Summary Food insecurity (FI) – i.e., the “lack of consistent access to enough food for an active and healthy life” - is a relatively common type of adversity in the United States and one which disproportionately impacts families in rural counties (e.g., ~17% of rural families experience FI, compared to ~10% of all US families). FI is associated with an increased risk for substance use (SU) in adults and adolescence and SU risk is also generally greater for adolescents in rural areas, compared to their urban and suburban peers. While a causal link between FI and SUD liability has not been established, prior work supports the postulation that the experience of FI might increase the risk for SU via an impact on the neural substrates of reward processing. For example, of the key components of FI (i.e., acute and repeated food deprivation and associated hunger, stress, and poor nutrition), stress and poor nutrition have been shown to influence SU-relevant neurodevelopmental trajectories, while food deprivation in children impacts neural processing for food rewards. Furthermore, in adult humans and animal models, food deprivation increases reward sensitivity and risky decision-making for primary and secondary rewards and increases drug-seeking and craving via functional alterations in reward network areas in the brain (i.e., mesocorticolimbic regions). To more fully understand how food deprivation in the context of FI might influence reward processes, this developmental study will examine whether states of acute food deprivation that are sufficient to cause subjective feelings of hunger enhance sensitivity for food and non-food rewards and increase risky decision-making (Aim 1). Moreover, we will consider how associations between food deprivation and the neural substrates of reward processing are impacted by FI (Aim 2) and whether FI mediates the associations between related factors (e.g., SES) and reward processes (Aim 3) To address these aims, children (8-10 years old) from food secure (N=30) and insecure (N=30) households in rural PA will undergo a counter-balanced, repeated measures fMRI paradigm, once while food deprived (i.e., fasted) and once after a meal sufficient to satiate them (i.e., fed). We will focus on children in order to minimize the impact of aspects of adolescence that might also influence these processes and confound our results (e.g., SU, puberty). During fMRI participants will complete 2 versions of a reward task in which they will make reward-related decisions (i.e., placing a bet of varying magnitude) for food (i.e., candy) and non-food (i.e., money) rewards Data analyses will model the impacts of food deprivation (fasted/fed; Aim 1) and food security status (secure/insecure; Aim 2) on reward neurobiology. Mediation analysis will consider the relative contributions of FI vs. SES (Aim 3) and exploratory analysis will consider potential moderators of FI-related effects (i.e., stress, nutrition, chronicity of FI; Aim 4). By considering whether food deprivation in the context of FI drives functional alterations in reward processes, this exploratory R21 study will constitute a critical first step in identifying pathways by which FI drives SU-liability.