School Age Children Tables - NCS Dietary Assessment Literature Review

School Age Children Tables

Table 5.1 - Validation of dietary assessment methods in school age populations

Table 5.2 - Summary Table: Surveys of school age populations

Exhibit 5.1. Respondent-observer issues in the dietary assessment of school age children and adolescents.a

Chronological Age School Age Adolescence
Dietary Habits
  • Rapidly changing food habits
  • Eating patterns generally structured
  • Under supervision of adults
  • More in-home eating than adolescence, but meals and snacks also at school, child care, and friends
  • Parental influence important
  • Rapidly changing food habits
  • Unstructured eating patterns
  • Less supervision by adults
  • Less in-home eating
  • Peer influence important
Cognitive Abilities
  • Low literacy skills
  • Limited attention span
  • Limited concept of time
  • Limited memory
  • Limited knowledge of food and food preparation
  • Dietary reporting by surrogate respondents
  • Full cognitive capability
  • Extensive knowledge of food, but food preparation experience may be limited
  • Responsibility for self-reporting
  • Food satisfies hunger
  • Food is a means of self-expression

a. Adapted from Livingston and Robson, 2000 (161).

Exhibit 5.2. Summary of validation studies on children age 6 to 12 years, reviewed by McPherson et al. (1;170)

24-Hour Recall
Description 3 studies evaluated full 24 hours (163;164;171); 6 studies evaluated portion of day, usually school lunch (140;141;172-175)
Reference Method TEE by DLW Method = 1 study (171)
Direct Observation = 7 studies (140;141;163;172-175)
Food Record = 1 study
Comparison with Reference Method Food recall underestimated intake = 5 studies (141;164;171;174;175)
Food recall overestimated intake = 4 studies (140;163;173)
Difference in mean energy intake ranged from 34% underestimation to 18% overestimation
Food Record (FR)
Description 2 studies evaluated audiotaped records, 1 day (164) or 7 days (171)
2 studies evaluated 7 consecutive days (171;176)
1 study evaluated 8 consecutive days (177)
1 study evaluated 3 and 7 non-consecutive days (178)
Reference Method TEE by DLW Method = 3 studies (171;176;177)
Direct Observation = 2 studies (164;178)
Duplicate portions = 1 study (178)
Comparison with Reference Method Food record underestimated intake = 4 studies
Food record overestimated intake = 2 studies
Difference in mean energy intake ranged from 28% underestimation to 31% overestimation
Correlation coefficients ranted from:
* 0.52 to 0.71 for energy;
* 0.56 to 0.66 for protein; and
* 0.58 to 0.63 for total fat.
Food Frequency Questionnaire
Description 13 studies, each using different FFQ instruments (128;146;167;179-188)
Reference Method TEE by DLW Method = 1 study (146)
7 day Food Record = 3 studies (128;180;183)
14 day Food Record = 4 studies (167;179;181;186)
14 day Food Checklist = 1 study (185)
22 day Fruit/Vegetable Record = 1 study (167)
24-Hour Recall = 3 studies (182;187;188)
Serum carotenoids, vitamins A, C, and E = 1 study (184)
Comparison with Reference Method FFQ overestimated intake in 12 studies (128;146;150;167;179-182;184-188)
In 3 studies comparing full diet FFQ with multiple FRs, correlation coefficients ranged from:
0.25 to 0.46 for energy;
0.18 to 0.34 for protein; and
0.19 to 0.39 for total fat.

Exhibit 5.3. Summary and conclusions from Livingston and Robson, 2000 review. (161)

Parental Recall of Dietary Intake Children (< 7 years)

  • Parents can be reliable reporters of their children's food intake in the home environment (139;140;143;144), particularly if both parents participate in the reporting process (141).
  • Parents may not be reliable reporters of the child's food intake out-of-home (139).

Portion Size Estimation in Children

  • Studies of the ability of children and adolescents to estimate portion size have shown inconclusive and contradictory results (163;164;186).
  • The assumption that inclusion of any quantification tool will improve the estimating capabilities of children has not been verified.
  • Portion size estimation improved with an intensive 45-minute training session in children age 9 to 10 years, but errors for several foods remained >100% (189).

Variability and Tracking of Nutrient Intake

  • The variance ratio (within-subject to between-subject ratio) of most nutrients is much higher in children and adolescents (5-17 years) than adults (190-194); ratios are approximately twice adult values and are consistently higher in females than males. Variability is lowest for nutrients eaten regularly and highest for nutrients eaten in large amounts only occasionally. Up to 20 days of recording may be required to capture habitual vitamin intakes.
  • Self-reported intakes, particularly in adolescents, are likely to be biased, mainly in the direction of underreporting (61;138;176;195;196).
  • Evidence for tracking (maintenance of relative position in rank over time) of nutrient intake over time is inconsistent for school age children and adolescents.

Validation of Dietary Intakes with DLW Method

  • The overall trend for energy intake underreporting tends to increase with increasing age; intakes from children younger than age 10 years are more accurate than from older children.
  • Obese children and adolescents underreport energy intake significantly more than do non-obese children and adolescents.
  • The influence of parental adiposity on children's food intake is inconsistent.
  • The small number of studies to date preclude any firm conclusions about the advocacy of one dietary assessment over another; the small number of studies suggest:
    • Weighed or estimated food records provide unbiased records of energy intake in lean children <9yrs; but adolescents underreport intake by 20% (138;176)
    • Diet History method overestimates energy intake in children age <9 years, but is accurate in older children (138)
    • 24HR energy intake accurate at group level for children age 4 to 7 yrs, but is not precise at the individual level (144)
    • FFQ overestimates energy intake by 53% in children age 4 to 7 yrs (146)
  • Evidence exists for a subject-specific response in dietary reporting; subjects who underreported by the weighed food record also did so by Diet History (138).

Detection of Misreporting

  • At present, the identification of the presence and magnitude of overreporting of energy intake is impossible; more experimentally-derived data on TEE assessed by the DLW method is needed to calculate the upper limit confidence intervals.
  • The selective underreporting of different foods has not been addressed in dietary studies of children and adolescents.
  • To detect misreporting, apply appropriate age- and gender-specific cut-offs for evaluating reported energy intake in pediatric populations by comparisons with presumed energy requirements; apply different cut-offs for subjects with low, medium, or high physical activity levels