Diet quality, as one of the key dimensions of food security, plays a decisive role in the health, productivity, and sustainability of rural household livelihoods. This study aimed to spatially and structurally analyze diet quality in rural areas of Iranian provinces. The data used included eight nutritional indicators (calories, carbohydrates, protein, iron, vitamins A, B1, and C, and calcium) and a set of rural socio-economic indicators extracted from official sources for the year 1403. The results showed that the first component (PC1) explains a dominant share of the total variance of nutritional data and is significantly loaded with most macronutrient and micronutrient indicators; this component was interpreted as the "general diet quality index." The spatial distribution of PC1 was examined at the provincial level, and Moran's global spatial autocorrelation test showed that the pattern of distribution of diet quality does not follow a meaningful spatial clustering and that nutritional differences between provinces are not necessarily influenced by geographical proximity. The clustering results divided the provinces of the country into three distinct clusters, each reflecting a specific pattern of interaction between diet quality, agricultural production, income inequality, and food cost pressures. The findings indicate that provinces with higher nutritional quality are not necessarily provinces with higher incomes, and in some cases, local agricultural production and rural consumption patterns have been able to compensate for economic constraints to some extent. In contrast, in some provinces, despite higher levels of economic development, dependence on food markets and the weakening of local food systems have led to a decline in diet quality.