LIMITATIONS IN THE ASSESSMENT OF DIETARY ENERGY-INTAKE BY SELF-REPORT

Development of the doubly-labeled water method has made it possible to test the validity of dietary intake instruments for the measurement o f energy intake. Comparisons of measured energy expenditure with energ y intake from either weighed or estimated dietary records against ener gy expenditure have indicated that obese subjects, female endurance at hletes, and adolescents underestimate habitual and actual energy intak e. Individual underestimates of 50% are not uncommon. Even in non-obes e adults, where bias is minimal, the standard deviation for individual errors in energy intake approaches 20%. Two investigations of the val idity of self-reported dietary records for measuring change in dietary intake also indicate large underestimates of the actual change. Becau se of bias and imprecision, self-reported energy intakes should be int erpreted with caution unless independent methods of assessing their va lidity are included in the experimental design. Copyright (C) 1995 by W.B. Saunders Company