Development of two short FFQ to assess diet quality in UK pre-school and primary school-aged children based on National Diet and Nutrition Survey data.

Assessing children's diets is currently challenging and burdensome. Abbreviated FFQ have the potential to assess dietary patterns in a rapid and standardised manner. Using nationally representative UK dietary intake and biomarker data, we developed an abbreviated FFQ to calculate dietary quality scores for pre-school and primary school-aged children. UK National Diet and Nutrition Survey (2008-2016) weekly consumption frequencies of 129 food groups from 4-d diaries were cross-sectionally analysed using principal component analysis. A 129-item score was derived, alongside a 12-item score based on foods with the six highest and six lowest coefficients. Participants included 1069 pre-schoolers and 2565 primary schoolchildren. The first principal component explained 3·4 and 3·0 % of the variation in the original diet variables for pre-school and primary school groups, respectively, and described a prudent diet pattern. Prudent diet scores were characterised by greater consumption of fruit, vegetables and tap water and lower consumption of crisps, manufactured coated chicken/turkey products, purchased chips and soft drinks for both age groups. Correlations between the 129-item and 12-item scores were 0·86 and 0·84 for pre-school and primary school-aged children, respectively. Bland-Altman mean differences between the scores were 0·00 sd; 95 % limits of agreement were -1·05 to 1·05 and -1·10 to 1·10 sd for pre-school and primary school-aged children, respectively. Correlations between dietary scores and nutritional biomarkers showed only minor attenuation for the 12-item compared with the 129-item scores, illustrating acceptable congruence between prudent diet scores. The two 12-item FFQ offer user-friendly tools to measure dietary quality among UK children.