Dietary patterns

Information on diet was collected from a previously validated 136-item semi-quantitative food-frequency questionnaire at baseline ^(21–23). For each food item, there were 9 possible answers on frequencies of consumption (never/seldom, 1–3 servings/month, 1 serving/week, 2–4 servings/week, 5–6 servings/week, 1 serving/d, 2–3 servings/d, 4–6 servings/d and >6 serving/d). We multiplied typical portion sizes by consumption frequency for each food item to calculate daily food consumption in grams and grouped these consumptions into 31 predefined categories⁽²⁴⁾. To identify the main DPs in the SUN Project, we performed a principal component analysis on these 31 food groups. The number of components to be extracted was determined by a screen plot test. Component loadings >0·25 were considered relevant for the DPs. Each participant score was obtained by summing the consumption of each food group weighted by the component specific loading. Quartiles were obtained from the quantitative score. In addition, Spanish food composition tables were used to derive the nutrient composition of dietary intake^(25,26).