Introduction The analysis of dietary patterns has become a valuable tool to examine diet-disease relations. However, little is known about the effects of dietary patterns on quality of life.

Objectives To ascertain the major dietary patterns in the SUN cohort and the association of the adherence to these dietary patterns with physical and mental health function.

Methods This analysis included 10 185 participants from the “Seguimiento Universidad de Navarra” (SUN) cohort. Dietary patterns were ascertained through a factor analysis based on 16 predefined food groups. Health related quality of life was measured after 4 years of follow-up with the Spanish version of SF-36 Health Survey. Generalised Linear Models were fitted to asses the mean scores and their 95% CIs (95% CI) of the 8 domains of the SF-36 according successive quintiles of adherence to the dietary patterns.

Results Two major dietary patterns were found. The “Western” dietary pattern (rich in fast food, high-fat dairy, read meats and processed pastries) and the “Mediterranean” pattern (characterised by fruits, vegetables, fish and olive oil). A high adherence to the Western pattern was associated with lower scores in vitality, general health and physical functioning with inverse dose response relationships (p<0.05). On the contrary, high adherence to the Mediterranean pattern was associated to higher scores in all of the physical domains, and in vitality and mental health with positive dose response relationships (p<0.05).

Conclusions Whereas the Western pattern seems to decrease vitality, the Mediterranean pattern increases vitality and physical wellness.