Number of days needed to assess energy and nutrient intake in infants and young children between 6 months and 2 years of age

Objective: To estimate the minimum number of days of recorded dietary intake needed to place infants and young children into thirds of a population distribution with an acceptable degree of accuracy. Design: Dietary intake data collected from 5-day weighed food records for 72 infants and young children up to 2 y of age, collected during a cross-sectional study, were analysed to estimate the number of recording days necessary to assess intake of energy and 10 nutrients. Setting: Community study among healthy infants and children. Subjects: Parents attended recruitment sessions in local community areas. In total, 72 subjects were entered into the study and all completed the 5-day dietary assessment period. Interventions: A 5-day weighed record of children's dietary intake was made by the parents or regular carer. Results: Mean within subject standard deviations were smaller than mean between subject standard deviations with respect to energy (778 vs 824 kJ/day), macronutrient subclasses: protein (8 vs 9.4 g/day); fat (9 vs 10 g/day); and carbohydrate (26 vs 29 g/day) and for specific micronutrients: calcium (163 vs 236 mg/day); phosphorus (143 vs 270 mg/day); magnesium (25 vs 43 mg/day); iron (2 vs 3 mg/day); zinc (1 vs 1.3 mg/day); ascorbic acid (27 vs 64 mg/day) and retinol equivalents (281 vs 424 microgram/day). Estimated number of days of food records necessary to assess intake of energy, protein, fat and carbohydrate with acceptable degree of accuracy were 5,4,4 and 3, respectively. For all the micronutrients included in this analysis 2 days of recording were necessary. Conclusions: Compared with adults and older children, fewer days are needed to classify this age group into thirds of the distribution with an acceptable degree of accuracy according to intake of energy and specific nutrients.