Validation of recall of body weight over a 26-year period in cohort members of the Adventist Health Study 2

Purpose: The validity of recall of past body weight has been measured and tends to be high; however, the paucity of validation data for recall in older age is noteworthy given the need for accounting for age and disease-related weight change in prospective studies. Methods: The Adventist Health Study-2 (AHS-2) is a prospective, questionnaire-based study (n = 96,710) that enrolled a cohort from 2002 through 2007 to investigate the role of lifestyle exposures (diet, physical activity, anthropometrics) and health on outcomes such as cancer and mortality. Results: The mean difference between current weight reported 26 years earlier in AHS-1 and recall of past body weight in AHS-2 was only 0.67 kg, indicating underestimation in the recall of past body weight from ages 30 to 70 years. Conclusions: Misclassification is differential across both age and adiposity, and this tendency needs to be incorporated into the interpretation of weight history and health outcome literature. © 2012 Elsevier Inc..