Objective: To evaluate the relative validity of an FFQ for assessing nutrient intakes in 12-month-old infants.
Design and setting: The FFQ was developed to assess the diets of infants born to women in the Southampton Women's Survey (SWS), a population-based survey of young women and their offspring. The energy and nutrient intakes obtained from an interviewer-administered FFQ were compared with those obtained from 4 d weighed diaries (WD).
Subjects and methods: A sub-sample of fifty infants (aged 1 year) from the SWS had their diets assessed by both methods. The FFQ recorded the frequencies and amounts of foods and drinks consumed by the infants over the previous 28 d; milk consumption was recorded separately. The WD recorded the weights of all foods and drinks consumed by the infants on 4 d following the FFQ completion.
Results: The Spearman rank correlation coefficients for intakes of energy, macronutrients and eighteen micronutrients, determined by the two methods, ranged from r = 0.25 to 0.66. Bland-Altman statistics showed that mean differences between methods were in the range +5% to +60% except for vitamin D (+106%). Differences in micronutrient intake were partly explained by changes in patterns of milk consumption between the two assessments.
Conclusion: Although there were differences in absolute energy and nutrient intakes between methods, there was reasonable agreement in the ranking of intakes. The FFQ is a useful tool for assessing energy and nutrient intakes of healthy infants aged around 12 months.