To evaluate the relative validity of an FFQ for assessing nutrient intakes in 12-month-old infants.

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 4d weighed diaries (WD).

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.

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.

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.

To evaluate the relative validity of a food frequency questionnaire (FFQ) for assessing nutrient intakes in 6-month-old infants.

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 a 4-day weighed diary.

A sub-sample of 50 infants aged 6 months from the SWS had their diets assessed by both methods. The FFQ recorded the frequencies and amounts of milks, baby foods, regular foods and drinks consumed by the infants over the previous seven days. The diaries recorded the weights of all foods and drinks consumed by the infants on four separate days within 15 days following FFQ completion.

Spearman rank correlation coefficients for intakes of energy, macronutrients and 18 micronutrients, determined by the two methods, ranged from r = 0·39 to 0·86; adjustment for energy intake tended to increase the correlation coefficients, range ra = 0·55 to 0·89. Bland–Altman statistics showed that mean differences between methods were in the range of −12·5 % to +12·5 % except for vitamin B12 (−18·9 %).

Although there were differences in absolute energy and nutrient intakes between methods, Spearman rank correlation coefficients indicated reasonable agreement in the ranking of intakes. The interviewer-administered FFQ is a useful tool for assessing energy and nutrient intakes of healthy infants aged about 6 months.