Association Between the Nutritional Quality of Food Purchases and Household Food at Home Expenditures in Mexico.

Background: Poor-quality diets are a major risk factor for noncommunicable diseases. Few studies in Mexico have tested whether higher expenditures are needed to purchase high-quality food.

Objective: The objective of the study was to assess how dietary quality of food purchases was associated with household food at home expenditures.

Design: This study was a secondary analysis of cross-sectional data from the National Household Income and Expenditure Survey (EncuestaNacional de Ingresos y Gastos de los Hogares [ENIGH] 2018).

Participants/setting: The study included 74 469 households with information on food and beverage purchases in Mexico in 2018.

Main outcome measures: Quarterly household food at home expenditures by adult equivalent (AE) for all food groups that were scored with the Global Dietary Quality Score (GDQS) for food purchases expressed in dollars/quarterly/AE.

Statistical analyses performed: Adjusted generalized linear models were used to evaluate the association between GDQS for food purchases (expressed in tertiles: low, mid, and high) and quarterly food expenditures. The analyses were performed at the national level by place of residence and income quintile.

Results: At the national level, the difference in food expenditures between the high- and the low-GDQS groups was +$13.85/AE. By place of residence, the difference between the high- and the low-GDQS groups was +$17.31/AE in urban and +$5.12/AE in rural areas. For income quintile 1 (lowest), there was a statistical difference of -$4.79/AE and +$43.25 for quintile 5 (highest).

Conclusions: Quality of food purchases can be associated with higher or lower expenditures depending on the specific food purchased. High GDQS is associated with lower expenditures among the lowest-income households as they purchase less expensive options compared with high-income households.