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.
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.
Authors: Tram Kim Lam; Amanda J Cross; Dario Consonni; Giorgia Randi; Vincenzo Bagnardi; Pier Alberto Bertazzi; Neil E Caporaso; Rashmi Sinha; Amy F Subar; Maria Teresa Landi Journal: Cancer Res Date: 2009-01-13 Impact factor: 12.701
Authors: Tram Kim Lam; Melissa Rotunno; Jay H Lubin; Sholom Wacholder; Dario Consonni; Angela C Pesatori; Pier Alberto Bertazzi; Stephen J Chanock; Laurie Burdette; Alisa M Goldstein; Margaret A Tucker; Neil E Caporaso; Amy F Subar; Maria Teresa Landi Journal: Carcinogenesis Date: 2009-12-31 Impact factor: 4.944
Authors: Filip Růžička; Robert Jech; Lucie Nováková; Dušan Urgošík; Josef Vymazal; Evžen Růžička Journal: PLoS One Date: 2012-05-30 Impact factor: 3.240