OBJECTIVE -This study assesses the validity of dietary data from African-American women with type 2 diabetes by comparing reported energy intake (EI) with total energy expenditure (TEE) estimated by an accelerometer and basal metabolic rate (BMR).
RESEARCH DESIGN AND METHODS -EI of 200African-American women was assessed by three telephone-administered 24-h diet recalls using a multiple-pass approach. Physical activity was measured over a 7-day period by accelerometer, which also provided an estimate of TEE. Underreporting of EI was determined by using cutoffs for EI-to-TEE and EI-to-BMR ratios.RESULTS -Participants, on average, were 59 years of age, with a BMI of 35.7, 10.5 years of diagnosed diabetes, and 10.7 years of education. Mean EI was 1,299 kcal/day; mean EI-to-TEE and EI-to-BMR ratios were 0.65 and 0.88, respectively. Among the 185 subjects with complete dietary data, 81% (n ϭ 150) were classified as energy underreporters using the EI-to-TEE ratio cutoff; 58% (n ϭ 107) were classified as energy underreporters using the EI-to-BMR ratio. Energy underreporters had significantly lower reported fat, higher protein, but similar carbohydrate intakes compared with non-underreporters. The EI-to-TEE ratio was not significantly associated with any demographic variables or following a diet for diabetes, but it was inversely associated with BMI (r ϭ Ϫ0.37, P Ͻ 0.0001). In a multivariate model, demographic variables, BMI, and following a diet for diabetes explained 16% of the variance in the EI-to-TEE ratio, with the latter two variables being the only significant predictors (inversely associated).
CONCLUSIONS -Widespread energy underreporting among this group of overweightAfrican-American women with type 2 diabetes severely compromised the validity of selfreported dietary data.
Diabetes Care 27:663-669, 2004A ccurate estimates of dietary intake are important in interpreting the effects of dietary interventions on dietary behaviors and treatment outcomes. Because assessments of dietary intake are generally obtained by self-report, they are prone to a number of reporting biases, which may lead to misrepresentation of actual intake and compromise the validity of the data. There is ample evidence that underreporting energy intake (EI) is a common phenomenon associated with dietary assessments (1-3). However, the degree of underreporting varies greatly, from 10 to 91%, depending on several population characteristics and the method, definition, or cutoff value used to classify energy underreporters. The most commonly identified characteristics associated with energy underreporting are high BMI (4 -6), female sex (7-9), increased age (10 -12), and the desire to lower body weight (13-15). Only a few studies, however, focus specifically on African Americans (16) or individuals with type 2 diabetes (17).The purpose of this research was to assess the validity of diet self-reports in a sample of older African-American women with type 2 diabetes by comparing reported EI with total energy expenditure (TEE) and basal metabolic rat...