EVALUATION OF 4 METHODS FOR DETERMINING ENERGY-INTAKE IN YOUNG AND OLDER WOMEN - COMPARISON WITH DOUBLY LABELED WATER MEASUREMENTS OF TOTAL-ENERGY EXPENDITURE

The accuracy and precision of four different food intake assessment me thods were evaluated in young and older women by comparing reported en ergy intakes with doubly labeled water measurements total energy expen diture (TEE). A study lasting 8 d was conducted in 10 young women aged 25.2 +/- 1.1 y ((x) over bar +/- SEM) and in 10 older women aged 74.0 +/- 1.4 y. Free-living TEE was measured over 7 d and food consumption was determined from weighed food intake data (7 d), a 24-h food recal l (in duplicate), and two different food-frequency questionnaires [Fre d Hutchinson Cancer Research Center (FHCRC)/Block and Willett, both in duplicate]. In addition, body composition was determined by using hyd rodensitometry, and strenuous physical activity and the extent of diet ary restraint were determined by questionnaire. In young women, 24-h r ecall gave mean energy intakes that were closest to measures of TEE (- 0.34 +/- 3.71 MJ/d compared with TEE, P = 0.178), and energy intakes b y food-frequency questionnaires were the only intake data that correla ted significantly with individual values for TEE (P < 0.05). In older women, food-frequency questionnaires gave mean energy intakes that wer e closest to measured TEE (+0.53 +/- 2.95 MJ/d with the Willett questi onnaire and -1.19 +/- 3.02 MJ/d with the FHCRC/Block questionnaire). N o energy intake data from this group correlated significantly with val ues for TEE. The 7-d weighed dietary intakes were significantly lower than measured TEE in both young and older women (-2.0 MJ/d in young an d older women combined, P < 0.001), and did not correlate significantl y with values for TEE, although they did most closely mirror the mean difference in TEE between the young and older women (2.30 MJ/d for TEE and 2.11 MJ/d for 7-d weighed intake). These data suggest that none o f the methods studied gave accurate estimates of the usual energy requ irements of individual subjects. In addition, the results suggest that for some types of studies, simple methods for assessing group mean di etary intake may actually give more accurate information than weighed dietary intakes.