The purpose of the present study was to analyse the evolution of the Spanish population’s global and regional adherence to the Mediterranean diet (MD) since 1987.

A cross-sectional study was conducted analysing food consumption from the Spanish Household Consumption Surveys administered by the Spanish Ministry of Agriculture, Fisheries and Food.

The Mediterranean Adequacy Index (MAI) was applied to measure the adherence to the MD. The significance of the MAI trend was evaluated using a regression model.

The sample comprises a household consumption data set, which consisted of 2500 households in 1987 and increased to 6200 in 2005.

There was a significant decrease in the MAI (P = 0·001) during the past two decades in Spanish households. From 1987 to 1997, MD adherence significantly decreased, but since 1998 it appears to have stabilised. In recent years, the daily household availability of several of the food components of the MD has increased. The MAI was observed to be significantly higher during the entire period in some Mediterranean regions, such as Andalusia, and significantly lower in more inland regions, such as Castile-Leon.

During the past two decades, Spain has experienced a significant downward trend in adherence to the predominant dietary pattern, likely as a result of numerous socio-economic changes. However, a stabilisation and a recent slight recovery have been observed during the past decade.