Income, food expenditure shares, and severe food insecurity in Australia across 21 waves of HILDA.

This study aimed to examine the association between household income and severe food insecurity in Australia and to assess how income-related patterns vary across geographic scales. Using 21 waves (2001-2021) of the Household, Income, and Labour Dynamics in Australia (HILDA) survey, we measured severe food insecurity through reported meal skipping due to financial constraint and food-related economic pressure through the share of household income spent on food. All estimates were weighted using HILDA population weights matched to each outcome. At the national level, weighted prevalence of meal skipping was 3.6% over the pooled sample (3.4% in the most recent wave), with a pronounced income gradient: individuals in the lowest income percentiles had a predicted probability of meal skipping exceeding 7%, compared with <1% at the 95th percentile. Food expenditure share declined monotonically with rising income, with households in the lowest quintile spending more than 30% of equivalized income on food. Among those who ever reported meal skipping in the balanced panel, the experience was episodic for most (5.8% of respondents reported it in exactly one of 21 waves) but recurrent for a nontrivial minority (9.1% in two or more waves). We formally tested whether prevalence in the Illawarra Shoalhaven region differed from the national average and found no statistically significant difference (F = 1.01, P = 0.315), suggesting that the income-gradient finding generalizes across geographic contexts. Severe food insecurity in Australia is strongly and persistently patterned by income, reinforcing income adequacy as the central policy lever for reducing hunger in high-income settings.