Toddlers - Background & Validation Studies - NCS Dietary Assessment Literature Review

See Infants and Toddlers tables

Toddlers Background

This stage of development is characterized by the slowing of the growth velocity and a rapid increase in fine and gross motor skills supporting increases in independence, exploration of the environment, and language skills (100). The slower rate of growth is reflected in a variable appetite, which is often of undue concern for parents as are the strong food preferences and dislikes many toddlers express. Weaning from the bottle is often complete by 12 to 14 months, but the age may vary. Toddlers gain the ability to handle chopped or soft table food and to use cups and spoons more effectively. Mealtime is messy as toddlers gain and practice self-feeding skills while continuing to eat with their hands. Because toddlers cannot eat a large amount at one time, snacks make a significant contribution to the child's nutrient intake. Recommended average serving sizes are small for toddlers, about one tablespoon of each solid food at 12 months increasing to just 2 tablespoons by age 2 years (100).

Assessing food and beverage intake in toddlers presents unique methodological issues. It is often difficult to quantify the amount a child consumes versus the amount offered. Most portion size estimating aides used with adult populations are not appropriate for toddlers. As in all young children, collecting information on the food and supplement intake of toddlers is complicated because parents often share the responsibility for the child with other adults in the home, at other homes, or at day care centers.

Validation Studies in Toddler Populations

Of the nine validation studies including children 13 to 24 months (Table 3.2), only four analyzed data separately for this age group. The DLW (Doubly Labeled Water) method for estimating TEE (Total Energy Expenditure) was validated with test weighing on 11 toddlers recovering from malnutrition on a metabolic ward in Lima, Peru (101). A 2001 study validated 5 days of estimated FR (Food Record) with 5 days of weighed FR in a cross-over study design on 34 toddlers (90). No significant differences were found between energy intake by estimated FR and weighed FR. DLW TEE measurements were within 7% of reported intakes of infants in this study but were not measured in the toddlers. A study of 20 toddlers found close agreement between reported energy intake in a diet history interview and a 3-day weighed FR (93).

In 2003, a 111-item HFFQ (Harvard Food Frequency Questionnaire) overestimated energy intake by more than 70 percent in a population of 24 toddlers compared with four quarterly 24HRs (24-Hour Recall (102). However, correlations between the HFFQ and plasma biological markers of several nutrients were promising: 0.51 for ascorbic acid, 0.48 for alpha-tocopherol, 0.41 for beta cryptoxanthin, and 0.39 for alpha carotene (102). In a WIC population of 233 1- to 5-year olds (55% were aged 1 to 2 years), energy intakes reported on an 84-item HFFQ agreed closely with measurements from three 24HRs for 20 nutrients were within 10% of the 24HR (103). More than half of the participants in this study were native Americans.

Kuehneman and colleagues (104) examined portion size estimating aides in a small population of children 18 to 36 months. Standard serving sizes for this age group showed the smallest error, compared with graduated food models, National Dairy Council food pictures, and standard Nasco plastic food models.

A recent cross-sectional survey evaluating a short questionnaire to assess risk factors for iron deficiency anemia, which included questions on diet and supplement use in children 9 to 30 months, found the questionnaire was not a valid first-stage screening method for iron deficiency anemia compared with hemoglobin, serum ferritin and MCV biomarkers (Table 3.3) (105).