The association of food security with psychological distress in New Zealand and any gender differences.

Food security (access to safe, nutritious, affordable food) is intrinsically linked to feelings of stress or distress and it is strongly associated with socioeconomic factors. However, the impact of food insecurity on mental health, independent of confounding socioeconomic factors, is not clear. We investigated the association of food insecurity with psychological distress in New Zealand, controlling for socioeconomic factors. Secondarily, we examined the association in males and females. We used data from the Survey of Families, Income and Employment (SoFIE) (N = 18,955). Respondents were classified as food insecure if, in the last 12 months, they: used special food grants/banks, had to buy cheaper food to pay for other things, or went without fresh fruit and vegetables often. Psychological distress was measured using the Kessler-10 scale dichotomised at low (10-15) and moderate to high (16+). Logistic regression analyses were used to investigate the association of food insecurity with psychological distress using a staged modelling approach. Interaction models included an interaction between food security and gender, as well as interactions between gender and all other covariates (significant at p-value < 0.1). Models were repeated, stratified by gender. A strong relationship between food insecurity and psychological distress was found (crude odds ratio OR 3.4). Whilst substantially reduced, the association remained after adjusting for confounding demographic and socioeconomic variables (adjusted OR 1.8). In stratified models, food insecure females had slightly higher odds for psychological distress (fully adjusted OR 2.0) than males (fully adjusted OR 1.5). As such, an independent association of food insecurity with psychological distress was found in both males and females--slightly more so in females. However, we cannot rule out residual confounding as an explanation for the independent association and any apparent gender interaction.