Validation study of energy expenditure and intake during calorie restriction using doubly labeled water and changes in body composition

BACKGROUND: Clinical trials involving calorie restriction (CR) require an assessment of adherence to a prescribed CR with the use of an objective measure of energy intake (EI). OBJECTIVE: The objective was to validate the use of energy expenditure (EE) measured by doubly labeled water (DLW), in conjunction with precise measures of body composition, to calculate an individual's EI during 30% CR. DESIGN: Ten participants underwent 30% CR for 3 wk. During the last week (7 d), 24-h EE was measured in a respiratory chamber and simultaneously by DLW (EEDLW). EI was calculated from 7-d EE measured by DLW and from changes in energy stores (ES) (weight and body composition). Calculated EI was then compared with the actual EI measured in the chamber by using the following equations: calculated EI (kcal/d) = EEDLW + DeltaES, where DeltaESFM/FFM (kcal/d) = (9.3 x DeltaFM, g/d) + (1.1 x DeltaFFM, g/d), FM is fat mass, and FFM is fat-free mass. RESULTS: We found close agreement (R = 0.88) between EE measured in the metabolic chamber and EEDLW during CR. Using the measured respiratory quotient, we found that the mean (+/-SD) EE(DLW) was 1934 +/- 377 kcal/d and EE measured in the metabolic chamber was 1906 +/- 327 kcal/d, ie, a 1.3 +/- 8.9% overestimation. EI calculated from EEDLW and from changes in ES was 8.7 +/- 36.7% higher than the actual EI provided during the chamber stay (1596 +/- 656 kcal/d). CONCLUSIONS: DLW methods can accurately estimate 24-h EE during CR. Although the mean difference between actual and calculated EIs for the group was small, we conclude that the interindividual variability was too large to provide an assessment of CR adherence on an individual basis.     

Validation of energy intake estimated from a food frequency questionnaire: a doubly labelled water study

OBJECTIVE: The validation of dietary assessment methods is critical in the evaluation of the relation between dietary intake and health. The aim of this study was to assess the validity of a food frequency questionnaire by comparing energy intake with energy expenditure measured with the doubly labelled water method. DESIGN: Total energy expenditure was measured with the doubly labelled water (DLW) method during a 10 day period. Furthermore, the subjects filled in the food frequency questionnaire about 18-35 days after the DLW phase of the study was completed. SUBJECTS: Twenty-one healthy, non-pregnant females volunteered to participate in the study; only 17 subjects completed the study. RESULTS: The group energy intake was on average 10% lower than the energy expenditure, but the difference was not statistically significant. However, there was a wide range in reporting accuracy: seven subjects were identified as acceptable reporters, eight as under-reporters and two were identified as over-reporters. The width of the 95% confidence limits of agreement in a Bland and Altman plot for energy intake and energy expenditure varied from -5 to 3 MJ. CONCLUSION: The data showed that there was substantial variability in the accuracy of the food frequency questionnaire at the individual level. Furthermore, the results showed that the questionnaire was more accurate for groups than individuals.     

Energy intake in Swedish adolescents: validation of diet history with doubly labelled water

OBJECTIVE: To compare habitual energy intake (EI) estimated from diet history (DH) with total energy expenditure (TEE) measured with doubly labelled water (DLW) in adolescents. DESIGN: DH included a detailed questionnaire and an interview. TEE was measured during a 14-day period. Adequate (AR), under- (UR) and over-reporters (OR) were defined from the ratio EI/TEE: AR 0.84-1.16, UR <0.84 and OR >1.16. SETTING: Participants were recruited from grade 9 in a compulsory school in G?teborg, Sweden. All data were collected at school and DLW dosages were distributed at Sahlgrenska University Hospital. SUBJECTS: A total of 35 adolescents (18 boys, 17 girls), 15.7 (0.4) y. RESULTS: EI was 11.0 (3.6) MJ and TEE was 11.4 (2.1) MJ (P=0.42). DH was able to rank EI compared to TEE (Spearman's r=0.59, P< or =0.001). For girls, EI was 18% lower (P=0.0067) and for boys, EI was 7% higher (P=0.26) compared to TEE. The 95% limits of agreement for difference between TEE and EI were -5.6 to 6.5 MJ. In total, 20 subjects were defined as AR (57%), nine as UR (26%) and six as OR (17%). Energy from in-between meals was 33% lower (P=0.0043) in UR girls and 57% higher (P=0.026) in OR boys, compared to adequate reporting girls and boys, respectively. In UR girls, energy-adjusted intake (10 MJ) of specific foods did not differ significantly, fat was lower and carbohydrate and vitamin C were higher compared to AR girls (all P<0.05). OR boys had no significant differences in food and nutrient intake in 10 MJ compared to AR boys. CONCLUSION: The diet history was able to capture EI for the group and to rank subjects. There was a wide individual range in reporting-accuracy related to gender. SPONSORSHIP: The Ingabritt and Arne Lundberg Foundation, The Wilhelm and Martina Lundgren Foundation.     

Calorie intake misreporting by diet record and food frequency questionnaire compared to doubly labeled water among postmenopausal women

OBJECTIVE: We assessed the extent of energy misreporting from the use of a self-administered 7-day diet record (7-DDR) and a widely used food frequency questionnaire (FFQ) compared to total energy expenditure from doubly labeled water (DLW) in a group of postmenopausal women. DESIGN: At baseline, 65 healthy postmenopausal women were instructed to fill out the National Cancer Institute's (NCI) FFQ and a 7-DDR. Average total energy expenditure using the DLW method was also performed at baseline. RESULTS: On average, the women underestimated total energy intake compared to total energy expenditure assessed from DLW by 37% on the 7-DDR and 42% on the FFQ. CONCLUSIONS: These findings suggest that the interpretation of findings from the 7-DDR- and FFQ-based energy-disease association studies in postmenopausal women needs further evaluation. SPONSORSHIP: This research was supported (in part) by the Intramural Program of the NIH (National Cancer Institute).     

Comparison of estimated nutrient intake by two methods: validation of a food frequency questionnaire

The validity of a quantitative self-administered food frequency questionnaire (FFQ) was tested by comparison with 7-d weighed food records (7DWR). Subjects for the study were 24 females between 20 and 43 years of age (mean = 24 years). The main aim of the FFQ was to classify subjects according to their total fat intake.
The mean nutrient intakes estimated by the FFQ were consistently and significantly higher than the estimates by the 7DWR. Rank correlations showed that the FFQ was able to rank subjects similarly for total energy intake, fat, alcohol and fibre intake as well as for the percentage contribution of macronutrients to energy intake. Intra-class correlations showed that the two methods did not agree at the individual level for energy and macronutrient intake except alcohol. These results suggest that the FFQ was suitable for ranking the subjects according to their total fat intake but was not suitable for estimating the individual nutrient intake or average nutrient intake of this relatively small group.     

In-person vs telephone-administered multiple-pass 24-hour recalls in women: validation with doubly labeled water

OBJECTIVE: To determine the accuracy of energy intakes estimated with the multiple-pass 24-hour recall method in women by conducting in-person and telephone interviews. Doubly labeled water measurements of total energy expenditure were used for validation. SUBJECTS: Thirty-five weight-stable women (mean age = 30 years, range = 19 to 46 years) participated. DESIGN: Total energy expenditure was measured over a 14-day period using the doubly labeled water method. During this time, 4 multiple-pass 24-hour recalls were obtained from the women (2 in-person, 2 by telephone) who were provided 2-dimensional food models to estimate portion sizes. The Food Intake Analysis System was used to analyze recall data. STATISTICAL ANALYSES: Paired t tests were conducted to examine differences between energy intake estimated from the telephone and in-person interviews. Agreement between the energy intake estimates from the telephone recalls and the in-person recalls was assessed using the technique of Bland and Altman. Paired t tests were used to compare energy intake estimated from the telephone and in-person recalls to total energy expenditure. RESULTS: No significant difference in mean daily energy intake was found between the telephone (2,253 +/- 688 kcal) and in-person (2,173 +/- 656 kcal) interviews (P = .36). However, the mean energy intake from each interview method was significantly lower than total energy expenditure (2,644 +/- 503 kcal) (P = .006 and .001, respectively). APPLICATIONS/CONCLUSIONS: Underreporting of energy intake was widespread in the sample. Although the multiple-pass 24-hour recall method did not generate a group measure of energy intake that was accurate or unbiased, the telephone-administered multiple-pass 24-hour recall was just as effective in estimating energy intake as the recall administered in-person. Dietetics professionals should be aware of the pervasive and serious problem of under-reporting of self-reported food intakes.     

Simultaneous measurement of free-living energy expenditure by the doubly labeled water method and heart-rate monitoring

Total energy expenditure (TEE) was measured simultaneously in 14 free-living adults over 15 d by the doubly labeled water (DLW) method and for 2-4 separate days by heart-rate (HR) monitoring. Individual curves for HR vs oxygen consumption (VO2) were obtained and an HR (FLEX HR: 97 +/- 8 beats/min, range 84-113 beats/min) that discriminated between rest and activity was identified. Calibration curves were used to assign an energy value to daytime HR above FLEX HR. Below FLEX HR energy expenditure was taken as resting metabolism. Sleeping energy expenditure was assumed to be equal to basal metabolic rate. Average HR TEE (12.99 +/- 3.83 MJ/d) and average DLW TEE (12.89 +/- 3.80 MJ/d) were similar. HR TEE discrepancies ranged from -22.2% to +52.1%, with nine values lying within +/- 10% of DLW TEE estimates. The FLEX HR method provides a close estimation of the TEE of population groups. However, an increased number of sampling days may improve the precision of individual estimates of TEE.     

Energy expenditure measured by doubly labeled water,activity recall,and diet records in the rural elderly

OBJECTIVE: The purpose of this study was to determine whether energy expenditure estimated from physical activity and energy intake were equivalent to total daily energy expenditure in an elderly rural population. METHODS: Twenty-seven elderly male (n = 14) and female (n = 13) subjects (mean age, 74 y) were recruited from a rural Pennsylvania population. Over a 2-wk period, total daily energy expenditure was measured by doubly labeled water (TEE) and estimated from 7-d physical activity recall factors multiplied by weight (PA(WT)), estimated basal metabolic rate (PA(BMR)) and resting energy expenditure from indirect calorimetry (PA(REE)), and energy intake from 3-d self-reported diet records (EI). Analysis of variance was used to determine significant within-subject differences in physical activity, energy intake, and energy expenditure. RESULTS: PA(REE) (men: 13.69 +/- 3.23 MJ, women: 9.51 +/- 2.40 MJ) and PA(BMR) (men: 13.69 +/- 2.99 MJ, women: 10.15 +/- 2.21 MJ) were not significantly different from TEE (men: 12.43 +/- 1.63 MJ, women: 9.44 +/- 0.90 MJ). EI (men: 8.66 +/- 2.34 MJ, women: 7.12 +/- 0.93 MJ) was significantly less than TEE, and PA(WT) (men: 17.03 +/- 4.07 MJ, women: 12.86 +/- 3.41 MJ) was significantly greater than TEE. CONCLUSIONS: Whereas 7-d physical activity recall determined with an age- and gender-specific estimate of resting metabolic rate or measured using indirect calorimetry accurately estimated TEE for this group of rural elderly, self-reported diet records consistently underestimated and physical activity recall determined with weight alone consistently overestimated energy expenditure measured by doubly labeled water.     

Energy expenditure and estimated caloric intake in asthmatic adolescents with excess body weight

ObjectiveTo measure resting energy expenditure (REE) and to estimate caloric intake of asthmatic adolescents with excess body weight and compare results with those groups of eutrophic asthmatic adolescents and non-asthmatic adolescents with excess body weight.MethodsThis cross-sectional study categorized 69 adolescents aged 10 to 18 y into three matched groups. Nutritional status was assessed using anthropometric and body composition measurements. Indirect calorimetry was used to measure energy expenditure, and caloric intake was estimated from dietary recalls.ResultsIn each group, there were 23 adolescents (10 girls) aged 12.39 ± 2.40 y. Results for each group were as follows. For asthmatic adolescents with excess body weight, body mass index (BMI) was 24.83 ± 2.73 kg/m², REEs were 1550.24 ± 547.23 kcal/d and 27.69 ± 11.33 kcal · kg^?1 · d^?1, and estimated caloric intake was 2068.75 ± 516.66 kcal/d; for eutrophic asthmatic adolescents, BMI was 19.01 ± 2.10 kg/m², REEs were 1540.82 ± 544.22 kcal/d and 36.65 ± 15.04 kcal · kg^?1 · d^?1, and estimated caloric intake was 2174.05 ± 500.55 kcal/d; and for non-asthmatic adolescents with excess body weight, BMI was 25.35 ± 3.66 kg/m², REEs were 1697.24 ± 379.84 kcal/d and 28.18 ± 6.70 kcal · kg^?1 · d^?1, and estimated caloric intake was 1673.17 ± 530.68 kcal/d. Absolute REE values between groups were not statistically different, even after correction for lean mass and fat mass (F = 0.186, P = 0.831). REE (kilocalories per kilogram per day) was significantly higher in the group of eutrophic asthmatic adolescents (P = 0.016). Estimated caloric intake was greater than REE only in the group of adolescents with asthma.ConclusionThe REE was not significantly different among groups, and REE (kilocalories per kilogram per day) was higher in the group of eutrophic asthmatic adolescents. Estimated caloric intake was greater than REE in the group of adolescents with asthma.     

Heart rate monitoring as a field method for estimating energy expenditure as evaluated by the doubly labeled water method.

Energy expenditure (TEE) determined by the doubly labeled water technique (DLW) in 10 adult subjects (5 males and 5 females) was used to evaluate the energy expenditure estimated from 24 h heart rate monitoring records (HR method) for 2 d randomly sampled during 2 weeks of DLW study. Individual data on HR and oxygen consumption, obtained during a step test (resting conditions, and up and down at 3 or 4 stepping rates) and postabsorptive conditions (resting metabolic rate: RMR), were used to calculate three types of calibration regression line, i.e., straight-linear regression (EE-HR: A for TEEhr-A), log-linear regression (lnEE-HR: B for TEEhr-B), and two-linear regression (flex-HR method: C for TEEhr-C). When the 24 h HR records were applied, these calibration regressions provided three estimates of TEE (mean +/- SD kcal/24 h): TEEhr-A (3,059 +/- 1,246 in all subjects), TEEhr-B (2,472 +/- 843), and TEEhr-C (2,759 +/- 1,228). Mean TEE determined by the DLW method (TEEdlw) was 2,544 +/- 378 kcal/24 h. Although no mean values estimated by HR methods were significantly different statistically from the mean value of TEEdlw, the variances of the estimates (e.g., SD) by the HR method were much greater than that of TEEdlw (between twofold and threefold). TEEhr-B estimated by lnEE-HR regression provided the smallest differences from that of TEEdlw (mean difference of -3.1% with a range of -35.1(-)+36.6%). From these observations, the following conclusions were made: 1) The estimates of TEE by HR are useful as a group mean, but interpretation of the individual TEE estimates requires caution because of great deviations from the reference values. 2) Among the calibration methods tested, the log-linear calibration regression (lnEE on HR) gives the best estimates of TEE by the HR method and is recommended for use in future studies.     

Energy requirements of urban Chinese adults with manual or sedentary occupations,determined using the doubly labeled water method

OBJECTIVE: To examine total energy expenditure (TEE) in relation to occupation and reported leisure time activities in free-living Chinese adults, and to determine whether measured TEE values differ from current international dietary energy recommendations. SETTING AND SUBJECTS: Seventy three weight-maintaining adults aged 35-49 y, leading unrestricted lives in urban Beijing, with a wide variety of occupations. DESIGN AND METHODS: A cross-sectional study in which TEE was determined by doubly labeled water, body composition by deuterium oxide ((2)H(2)O) dilution, resting energy expenditure (pREE) by prediction equations, and occupational and leisure time activities by questionnaire. RESULTS: For men and women respectively, TEE averaged 12.10+/-0.32 and 9.53+/-0.23 MJ/day (P<0.001), and physical activity level (PAL=TEE/pREE) was 1.77+/-0.04 and 1.66+/-0.02 (P<0.05). Fat-free mass (FFM) was the single best predictor of TEE (adjusted r(2)=0.71, P<0.001). Occupational category (light, moderate and heavy) further predicted TEE, independent of FFM (adjusted multiple r(2)=0.82, P<0.001). Both TEE adjusted for weight and PAL increased with occupational category. Measured TEE was slightly but significantly higher than the 1985 FAO/WHO/UNU estimates for women with light occupations, but did not differ from estimates for men with light occupations, or for adults with moderate or heavy occupations. CONCLUSION: Level of occupational activity, but not duration or type of leisure activity, significantly predicted TEE in free-living urban Chinese adults. Current energy requirement recommendations slightly underestimated the energy needs of women with light occupations but were accurate for men and women with moderate and heavy occupations. SPONSORSHIP: NIH grants DK53404 and F32-DK09747.     

Energy expenditure in underweight free-living adults: impact of energy supplementation as determined by doubly labeled water and indirect calorimetry

The effect of energy supplementation was evaluated in six underweight adults under free-living conditions. Customary energy intake (EI) over 4 wk and estimated body composition were defined. Then for 12 wk subjects were fed their customary EI under controlled conditions to assure stable energy reserve. Finally, intake was increased by a mean of 720 kcal/d for 8 wk adjusted to increase body fat from 9 to 18%. Body weight (means +/- SD) increased from 55.2 +/- 3.4 to 57.0 +/- 4.2 kg. Body fat gain was highly variable ranging from 0.6 to 3.8 kg. Energy expenditure (EE) by the factorial and doubly labeled water methods did not change. Fat storage accounted for 66% of the supplemental energy; 237 kcal/d remained unaccounted for. EE by the factorial method, which uses indirect calorimetry or isotopic measurements, were highly correlated (r = 0.8; p less than 0.01). Under the conditions of this study EI does not affect EE. The labeled water method permits the evaluation of energy expenditure in free-living conditions.     

Validation of a self-administered food-frequency questionnaire administered in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study: comparison of energy, protein, and macronutrient intakes estimated with the doubly labeled water, urinary nitrogen, and repeated 24-h dietary recall methods.

BACKGROUND: The validation of dietary assessment instruments is critical in the evaluation of diet as a chronic disease risk factor. OBJECTIVE: The objective was to assess the validity of a self-administered food-frequency questionnaire by comparison with dietary recall, urinary nitrogen excretion, and total energy expenditure data. DESIGN: Over a 1-y period, data from twelve 24-h dietary recalls, a food-frequency questionnaire, and four 24-h urine samples were obtained from 134 study participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) Study in Potsdam, Germany. In a substudy of 28 participants, total energy expenditure from doubly labeled water measurements was assessed. RESULTS: Energy-adjusted, deattenuated correlation coefficients between the questionnaire and the recalls ranged from 0.54 for dietary fiber to 0.86 for alcohol. Cross-classification of quintiles of nutrient intakes from the questionnaire and recalls indicated severe misclassification to be <4%. Reported protein intake correlated with estimated protein excretion (r = 0.46). Energy intake and total energy expenditure were also significantly correlated (r = 0.48); however, all but one subject underreported their energy intake. The magnitude of underreporting varied considerably, by 22% on average, and increased slightly with increasing energy intake. A similar pattern of underreporting was observed when energy intakes from the 24-h dietary recalls were compared with total energy expenditure. CONCLUSIONS: These data indicate an acceptable relative validity of the food-frequency questionnaire in this study population. Compared with measurements of total energy expenditure and protein excretion, however, only moderate agreement with both the food-frequency questionnaire and the 24-h dietary recalls was observed.