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. (C) 2012 Elsevier Inc. All rights reserved.