Ability and accuracy of long-term weight recall by elderly males: the Manitoba follow-up study.

PURPOSE: To assess the ability and accuracy of elderly men to recall their weights and determine what characteristics might predict recall ability and accuracy.
METHODS: Eight hundred sixty-nine elderly men (mean age, 84 years), participants of the Manitoba Follow-up Study (MFUS), responded to a questionnaire asking them to recall their weights at ages 20, 30, 50, and 65 years. Recalled weights were compared with measured weights collected since MFUS began in 1948. Logistic regression was used to predict ability and accuracy of weight recall.
RESULTS: Only 75% of respondents attempted to recall their weights at all 4 ages. Among men recalling 4 weights, fewer than half were accurate within +/- 10%, just 7% were within +/- 5% of their measured weights. Accuracy of recall was significantly and independently associated with body mass index during middle age (5 kg/m(2)) (odds ratio 0.83, 95% confidence interval: 0.76, 0.90) and weight change. Unmarried men were less likely than married men to attempt recalling all 4 weights. Men overweight at middle age were more likely to underestimate their recalled weights.
CONCLUSIONS: Studies relating weight in early adulthood or middle age with outcomes in later life should not rely on elderly male participants recalling those weights.