Dietary intake was assessed by using a food frequency questionnaire (FFQ). The FFQ was developed for Lifelines to assess dietary risk factors for a considerable number of diseases. Since this resulted in a long and time-consuming questionnaire, the questionnaire was divided into four parts and called the Flower Food Frequency Questionnaire. The questionnaire consists of one basic questionnaire, the heart of the flower and covers energy and macronutrient intake. The other three questionnaires, the petals, cover the (micro)nutrients. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5691752/#B13-nutrients-09-01136

The questionnaire