Adjusting for energy intake--what measure to use in nutritional epidemiological studies?

TitleAdjusting for energy intake--what measure to use in nutritional epidemiological studies?
Publication TypeJournal Article
Year of Publication2004
AuthorsJakes, RW, Day, NE, Luben, R, Welch, A, Bingham, S, Mitchell, J, Hennings, S, Rennie, K, Wareham, NJ
JournalInt J Epidemiol
Volume33
Issue6
Pagination1382-6
Date Published2004 Dec
ISSN0300-5771
KeywordsBody Weight, Diet Records, Energy Intake, Energy Metabolism, Epidemiologic Methods, Exercise, Female, Heart Rate, Humans, Male, Middle Aged, Nutrition Surveys, Surveys and Questionnaires
Abstract

BACKGROUND: The measurement of energy intake in epidemiological studies is difficult. However, it is important that energy intake is assessed if epidemiological analyses are to correspond to isocaloric experiments. The aim of this study was to compare self-reported energy intake, physical activity, and body weight with energy expenditure measured by 4 days of heart rate monitoring with individual calibration of the relationship between heart rate and oxygen consumption.METHODS: Volunteer sub-study of 97 men and women (mean ages 54 and 51 years respectively) within the European Investigation into Cancer (EPIC) study in Norfolk (UK). Dietary assessment of energy intake and physical activity was by self-report and weight was measured using standard techniques. Energy expenditure was assessed objectively by recording heart rate for 4 days following a calibration of the relationship between heart rate and oxygen consumption.RESULTS: Self-reported energy intake by 7-day diary (mean 8.5 MJ/day) and food frequency questionnaire (FFQ) (mean 8.8 MJ/day) were significantly lower than objectively measured total energy expenditure (mean 11.2 MJ/day). The deattenuated partial correlations between total energy expenditure were 0.33 (7-day diary), 0.34 (FFQ), 0.50 (physical activity), and 0.56 (weight). Weight accounted for 31% (deattenuated) of the sum of squares about the mean of true energy intake after adjusting for age and sex. With the addition of self-reported physical activity, the model was significantly improved (R2 = 0.57). Adding energy either assessed by the diary or FFQ did not improve the model.CONCLUSIONS: The results presented here indicate that to adjust for energy intake, for the purpose of replicating an isocaloric experiment in an observational epidemiological study, one would do considerably better adjusting for weight and physical activity, than adjusting for energy intake estimated from an FFQ.

DOI10.1093/ije/dyh181
Alternate JournalInt J Epidemiol
Citation Key10.1093/ije/dyh181
PubMed ID15333618