Poor diet quality exacerbates risks for acute and chronic conditions. People experiencing food insecurity have an increased likelihood of lower diet quality; however, this has not been investigated in the Australian context. The aim of this cross-sectional study was to examine whether the diet quality of Australian adults differed according to their household food security status. Data were analysed from a nationally representative sample (≥19 years; n = 9115) collected as part of the National Nutrition and Physical Activity Survey 2011-12. Household food security status and socio-demographic and health characteristics were assessed using data from an 18-module health interview. A 24 h dietary recall was used to estimate food and nutrient intakes and to calculate the Dietary Guidelines Index (DGI). DGI is a food-based score (0 to 130) that assesses adherence to the 2013 Australian Dietary Guidelines. Survey-weighted linear regression models, adjusted for age and sex, were used to examine diet quality (total DGI and component scores), and total energy and nutrient intake by food security status. Adults from food-insecure households had a mean total DGI score 3.5 points lower (95% CI -5.57, -1.46) than food-secure adults (p = 0.001). Adults from households experiencing food insecurity, when compared to those who were food-secure, had several lower DGI component scores including for dietary variety (1.6 vs. 2.3, p = 0.009), fruit (3.8 vs. 5.0, p = 0.001) and vegetables (3.7 vs. 4.4, p = 0.010). Adults from food-insecure households consumed on average more carbohydrates (45.6 vs. 43.3, p = 0.004) and total sugar (21.8 vs. 19.0, p = 0.003) as a percentage of daily energy and less protein (18.5 vs. 17.2, p = 0.004), mono-unsaturated fats (11.2 vs. 11.8, p = 0.026) as a percentage of daily energy, and fibre (20.1 vs. 23.0, p = 0.003), than food-secure adults. Sub-optimal diet may be one of the contributing factors to, or outcomes of, poorer health in food-insecure populations. Food security interventions are required to better address nutrition in food-insecure households and should be tailored to the health and socio-demographic characteristics of this population.
Keywords: adults; diet quality; food security; nationally representative survey; nutrition inequities.