The validity of self-reported weight loss and weight gain efforts in adolescents

There has been a proliferation of epidemiological survey studies of weight reducing and eating behaviors in adolescents; however, the validity of these self-report questionnaires has received little attention. The present study was designed to determine whether self-report measures of efforts to lose or gain weight and use of specific weight control methods are consistent with other measures. There were 98 high school volunteers who completed a questionnaire about weight change efforts. Parallel versions of the questionnaire were also returned by a parent and a friend or sibling. There were 165 high school subjects who completed the questionnaire and also recorded food intake, exercise, and various weight control methods for 7 days. External raters agreed with subjects' reports that they were trying to lose weight, and weight losers consumed much less food according to their eating records. Self-reported weight gainers consumed much more food than others, but agreement with external raters was lower. External raters agreed with subjects who reported skipping meals and exercising to lose weight, and the subjects exhibited these behaviors more frequently in their eating records. However, there was low consistency between the self-report questionnaire and external measures of drastic weight control behaviors, such as vomiting and fasting. With the exception of drastic weight control behaviors, the results of this study are generally positive for the validity of self-report questionnaires.