To analyse the factors associated with the level of adherence to a Mediterranean dietary pattern in healthy Spanish women before pregnancy.

A prospective series of 1175 women. An FFQ validated in Spanish populations served to collect dietary data. The Mediterranean Diet Adherence Index was used to assess the level of adherence to a Mediterranean diet pattern. Polytomic regression was performed to identify the associated factors.

Catchment area of Virgen de las Nieves University Hospital, Andalusia, Spain.

The women were invited to participate in the study at the 20th–22nd gestational week. The selection criteria were: Spanish nationality, 18 years of age or older, singleton pregnancy and absence of health problems that required modifying the diet or physical activity.

An inverse relationship was found between women's age and level of adherence to a Mediterranean diet pattern, with a clear dose–response association: a younger age entailed worse adherence (P < 0·001). The habit of smoking and sedentary lifestyle had a positive relationship with low adherence, giving OR = 5·36 (95 % 1·91, 15·07) for women who smoked >20 cigarettes/d and OR = 2·07 (95 % CI 1·34, 3·17) for sedentary women. Higher age, higher educational level, and higher social class of the women were associated with a higher level of adherence to the Mediterranean diet (P < 0·001).

In our sample population, younger age, lower social class, primary educational level and elements of an unhealthy lifestyle such as smoking and lack of exercise were associated with low adherence to a Mediterranean diet.