We plan to collect dietary data as part of the clinic being planned in the ALSPAC participants.They will be asked to complete three 24-hour dietary recalls, using a newly developed online system (exact tool to be determined - we are currently negotiating with two research groups over their tools: Jane Cade's MyFood24 (Leeds University) and Emma Foster's INTAKE24 (University of Newcastle)) at around the age of 24. YPs will be requested to complete a recall prior to coming to a clinic planned to start in June 2015. There will then be opportunity for the YP during the clinic visit to ask any questions about their dietary recall. The tool we use will automatically provide us with all the data necessary (food groups and nutrient intakes as derived using standard food tables). The tool will be both smart phone and tablet compatible. This means at least one recall could be collected during the clinic visit if time is available between sessions (we anticipate it will take 10-15 minutes to complete one recall) if we were to purchase a number of tablets. Reminders will then be sent out via email/text after the clinic visit to complete futher 24-hour recalls.

We also propose the collection of new questionnaire data in the YPs, to include questions such as current living arrangements (who, what, where), what the YP is currently doing (work, study etc), who normally prepares food etc and other eating behaviours. Such questions will be included in either the 2014 or 2015 Q as appropriate (but ideally 2014 from a temporal point of view, though we acknowledge funding may not be in place in time).

In addition to examining food groups and nutrient intakes, we will use three methods: cluster analysis, principal components analysis and reduced rank regression to obtain dietary patterns: All these methods reduce the complex nature of many inter-correlated dietary variables into a smaller number of variables which best describe the overall patterns of diet in the population but result in different outcome variables providing slightly different ways of assessing overall diet. These methods have been used extensively by the applicants to determine dietary patterns throughout childhood and into adolescence and will be used to see whether dietary patterns track into adulthood.

The ALSPAC resource provides the perfect opportunity to develop causal models that will explore which of the following are most important in determining 'healthy' dietary intake in early adulthood:

* Individual factors such as previous diet (including breastfeeding and weaning and dietary intake throughout childhood and in early adolescence), eating behaviours (such as skipping breakfast) physical activity, body composition, life events and other health behaviours;

* Familial factors such as parental diet, eating attitudes and behaviours, lifestyle and health factors

* Social and environmental factors such as housing, education of both the individual and their parents.