Studies in Adolescent Populations
Table 6.2 presents
summary data from epidemiologic surveys with at least 100 subjects collecting
food and supplement intake data from adolescent populations.
The two most recent US nutrition monitoring surveys, the 1999-2000 National
Health and Nutrition Examination Survey (NHANES) and the 1994-96 Continuing
Survey of Food Intake of Individuals (CSFII), each included 24HR (24-Hour
Recall) interviews to assess food and beverage intake. In both surveys,
adolescents were interviewed independently without a parent or guardian.
The diet-related questions in NHANES, CSFII, and the integrated What We
Eat in America-NHANES survey, which is currently in the field, are presented
in Table 2.5 (in
the Pregnancy and
Lactation section). The rationale for selecting instruments for the
integrated survey as well as the history of past CSFII and NHANES surveys
were recently reviewed (9).
The integrated What We Eat in America-NHANES includes two 24HR interviews,
one in-person and one by telephone, and a propensity questionnaire (100-item
History Questionnaire, without portion size information) in all children
older than age 2 years. For the 24-hr recalls, the probes and portion size estimates aides are
the same for both adolescents and adults. Likewise, the propensity questionnaire
does not contain any adaptations for adolescent populations. Supplement
use is queried in a separate questionnaire on frequency, dosage, and duration
of use of specific products.
Food records were used in seven of the surveys in Table 6.2. With adolescents,
food records present a challenge in terms of motivation and compliance.
A longitudinal study of female adolescents experienced a 28 percent loss
in subjects over a 6-year period (261).
In the US, the Youth Adolescent Questionnaire (YAQ) has been used in
several studies, including studies of diverse populations. The Bogalusa
Heart Study FFQ (Food
Frequency Questionnaire) has received more limited use. Various forms
of 24HR interviews were adopted by the other surveys listed.
Most of the surveys listed in Table 6.2 did not report methodology for
assessing the intake of vitamin and mineral supplements.