[What is the diet of the immigrant population resident in Spain? Results based on a systematic review].

Diet is a principal determinant of health and is interrelated with socioeconomic factors and the acculturation of immigrants. The aim of this study was to examine the existing evidence on food, nutrition, and diet amongst immigrant populations in Spain, its relationships with their countries of origin, and to evaluate the methodological quality of these studies. A systematic review was carried out that included seventeen cross-sectional studies, 71% of them were of average quality and only one was excellent; seven dealt with adolescents and ten dealt with adults, with a total of 9,871 participants. Insights on immigrant diet and nutrition were heterogeneous because the participant groups in these studies were from several different countries, each of which has distinct cultural and geographical characteristics. Adolescent diet was of lower quality, positively correlated to socioeconomic level; acculturation and length of residence were related to both positive (such as healthier dietary patterns, better adhesion to intake recommendations) and negative aspects (higher intake of meat or bakery products, lower intake of vegetables or fish, among others). Adults show a better intake of macronutrients, but a lower intake of micronutrients and non-observance of some intake recommendations; acculturation and length of residence were related to healthier dietary patterns, significantly related to type of employment. Immigrants from Mediterranean countries show a healthier diet than other immigrants, although the quality of their diet is worse than that of their peers in their countries of origin. Finally, the quality of the diet of non-Mediterranean immigrants improves when they become resident in Spain.