Accuracy of recalled body sizes

Nutrition Research Newsletter, Oct, 2004

Valid measures of recalled childhood and adolescent weight status should be of interest because of a growing interest in childhood determinants of adult diseases associated with obesity,. Several studies have indicated that adults are able to recall their earlier weights and heights fairly accurately, although heights tend to be overestimated and weights underestimated. There are limited data on whether the accuracy of recalled weight and body size varied by race or ethnic group because few studies have had multiethnic samples. Therefore, a present study in Obesity Research assessed the accuracy of children's reports of their current body size and the accuracy of women' recall of body size during childhood. In addition, Field et al. assessed whether race/ ethnicity, age, BMI or weight concerns were correlates of errors in recall.

Data was used from the prospective cohort study (the National Heart, Lung, and Blood Institute Growth and Health Study [NGHS]) of 1890 white and black women who were 9 to 10 years old at time of enrollment and were followed up 10 to 13 years later. At enrollment, the subjects had their weight and height measured and were asked to indicate their current body size from a series of nine pictograms. A sample of the subjects also had their body size evaluated by interviewers. At the follow-up part of the study, BMI in young adulthood was calculated from self-reported height and weight information. They were also asked to recall their body size at 9 and 10 years old using the pictograms and to indicate their level of concern with their weight.

The BMI measurements at baseline were moderately to strongly correlated with the child's body size rating at baseline and interviewer's rating of the participants at baseline. Among the women with interviewer assessments, 84% of the white and 67% of black recalled a body size that was within one body size of the interviewer's assessment. Race was not related to underestimating body size at baseline, but independent of weight status at baseline and age, black women were 80% more likely than white women to report a larger size at baseline than the interviewer selected. Approximately 19% of the girls (14% of whites and 25% of blacks) reported that they looked at least as large as the cut-off value used to classify children as overweight. However, among the 160 girls who were objectively underweight at baseline, 28% reported that they looked like figures close to or at the cutoff for being overweight.

In terms of ranking, recall of childhood body size was good. However, compared with the interviewer's assessment, there was evidence of underestimation. The discrepancy between recalled size and interviewers' assessment of the participants' size was most pronounced for the three leanest body figures. In addition, the higher rate of underestimation of size by black women suggests that body figure ratings work best for white women. Further research is needed to assess whether the use of pictograms that are more race-neutral or ethnically appropriate improves the relationship between self-reported and interviewer assessment of body shape among black women.

Alison E. Field, Debra L. Franko, Ruth H. Striegel-Moore, et al., Race differences in accuracy of self-reported childhood body size among white and black women, Obesity Research 12(7): 1136-1144 (July 2004) [Address correspondence to Alison E. Field, Division of Adolescent Medicine, 300 Longwood Avenue, Boston, MA 02115. E-mail: Alison.Filed@childrens.harvard.edu]