Objective: To devise a measure of diet quality from a short-form FFQ (SFFFQ) for population surveys. To validate the SFFFQ against an extensive FFQ and a 24 h diet recall.
Design: Population-based cross-sectional survey.
Setting: East Leeds and Bolton in Northern England.
Subjects: Adults (n 1999) were randomly selected from lists of those registered with a general practitioner in the study areas, contacted by mail and asked to complete the SFFFQ. Responders were sent a longer FFQ to complete and asked if they would take part in a telephone-based 24 h diet recall.
Results: Results from 826 people completing the SFFFQ, 705 completing the FFQ and forty-seven completing the diet recall were included in the analyses. The dietary quality score (DQS), based on fruit, vegetable, oily fish, non-milk extrinsic sugar and fat intakes, showed significant agreement between the SFFFQ and the FFQ (κ=0·38, P<0·001). The DQS for the SFFFQ and the diet recall did not show significant agreement (κ=0·04, P=0·312). A number of single items on the SFFFQ predicted a 'healthy' DQS when calculated from the FFQ. The odds of having a healthy diet were increased by 27 % (95 % CI 9, 49 %, P<0·001) for an increase in fruit of 1 portion/d and decreased by 67 % (95 % CI 47, 79 %, P<0·001) for an increase in crisps of 1 portion/d.
Conclusions: The SFFFQ has been shown to be an effective method of assessing diet quality. It provides an important method for determining variations in diet quality within and across different populations.
Keywords: Diet quality; Diet screener; Public health; Short dietary questionnaires.