Participants were given a diet questionnaire to complete and return alongside the LBC1936 Study Questionnaire. The Scottish Collaborative Group Food Frequency Questionnaire, version 7.0, was used [73]. This consists of a list of 175 items of food or drink presented in 23 sections. Participants were asked to indicate how often they consumed a pre-determined measure of each of these items over the last 2–3 months, ranging from 'rarely or never' through to '7+ a day'. Supplementary questions were included to clarify consumption of various items including bread, sugar, spreads and oils, vitamins, minerals and food supplements, and foods not included elsewhere in the questionnaire. The Food Frequency Questionnaires were sent to the University of Aberdeen for nutrient extraction, and the data then added into the overall analysis.
