Changes in Food at Home Purchases in Mexico Associated With the North American Free Trade Agreement: An Interrupted Time Series Analysis

Summary

This study used interrupted time series analysis to evaluate the association between NAFTA implementation (1994) and changes in Mexican household food purchases over 34 years (1984–2018). The analysis revealed that NAFTA was associated with immediate reductions in purchases of healthier staples (milk, basic foods) and sustained increases in less nutritious options (sugar-sweetened beverages, energy-dense foods), suggesting trade policy substantially reshaped household food consumption patterns in ways potentially adverse to population nutrition.

Regional applicability

This study conducted in Mexico is not directly applicable to United Kingdom conditions, but offers relevant methodological and policy insights: it demonstrates how trade agreements can reshape food supply chains and purchasing behaviour at population scale. The findings may inform UK policy discussions on food security and dietary quality in relation to trade agreements post-Brexit, though the socioeconomic and agricultural contexts differ substantially.

Key measures

Quantity of milk (ml/AE), basic foods (g/AE), sugar-sweetened beverages (ml/AE), nonessential energy-dense foods (g/AE), cereals (g/AE), tortillas (g/AE), and plant-based foods (g/AE) purchased per adult equivalent

Outcomes reported

The study measured changes in quantity of food and beverages purchased by Mexican households before and after NAFTA implementation in 1994, using interrupted time series analysis from 1984–2018. Key outcomes included reductions in milk and basic food purchases and increases in sugar-sweetened beverages and energy-dense foods.

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