Predicted and measured resting energy expenditure in healthy young women

Basal energy expenditure (BEE) was either measured by indirect calorimetry or predicted by different formulae in 104 young women: 74 lean and overweight subjects (normal weight, NWt) and 30 obese subjects. The predictive equations were based on weight alone (Owen, FAO-1, Schofield-1) or on weight and height (Harris-Benedict, Mifflin, Kleiber, and again FAO-2 and Schofield-2). With the exception of the Owen equation all the equations over-estimated measured BEE in both study groups. The ratio between measured and predicted value (% MP) varied between 102.3 (Owen) and 87.7 (Kleiber) in the NWt subjects and between 113.2 (Owen) and 89.3 (Schofield-1) in the obese subjects. The range including 95% of the predicted-measured differences (PMdiff) was larger than 1700 kJ/d in the NWt group and 2300 kJ/d in the obese group. In both study groups most of the equations showed a significant relationship between PMdiff and/or % MP with body weight and the magnitude of BEE. In conclusion, these equations are of little help in predicting BEE in a single subject and should be used with caution when assessing energy requirements in populations or groups of subjects.     

Estimation of energy expenditure and maintenance energy requirements of college-age men and women

Data from two nationwide dietary surveys have led to the suggestion that human energy requirements have been overestimated. A 5-wk energy balance study was conducted to estimate the energy expenditure and maintenance energy requirements of 12 college-age men and women, 20 to 29 yr of age, by the factorial method and by measurement of energy intake and changes in body energy content (intake/balance technique). Mean daily energy expenditure estimated by the intake/balance technique and the factorial method, respectively, was 3081 and 3040 kcal (r = 0.90) for the male subjects and 2183 and 2283 kcal (r = 0.53) for the female subjects. Although differences between the intake/balance and factorial estimations of energy expenditure tended to be greater for individuals than groups and for females than males, the factorial method as performed in this study provided accurate estimations of energy expenditure. In addition, the estimated energy requirements of the college-age subjects in this study provide evidence to support the Recommended Dietary Allowances for energy for this age group.     

Total energy expenditure of healthy Swedish women during pregnancy and lactation.

Total energy expenditure (TEE) was estimated in healthy Swedish women by the doubly labeled water method in a longitudinal study during pregnancy and lactation. Measurements were made before pregnancy (A); in gestational weeks 16-18 (B), 30 (C), and 36 (D); as well as 2 (F) and 6 (G) mo after delivery. When the results were interpreted, earlier published data regarding resting metabolic rate (RMR), energy intake, and energy in breast milk were also considered. TEE (MJ/d) and TEE/RMR were 10.5 +/- 2.2 (mean +/- SD) and 1.87 +/- 0.42 (n = 28), 9.6 +/- 2.8 and 1.65 +/- 0.67 (n = 22), 12.5 +/- 3.4 and 1.82 +/- 0.45 (n = 22), 12.2 +/- 4.1 and 1.66 +/- 0.52 (n = 19), 10.6 +/- 2.0 and 1.82 +/- 0.41 (n = 23), and 10.8 +/- 2.7 and 1.79 +/- 0.42 (n = 23) at A, B, C, D, F, and G, respectively. The results indicated that physical activity tended to be decreased during early pregnancy. Taking changes in body energy stores into consideration, it was estimated that subjects recorded 86% and 77% of their energy intakes at A and F respectively.     

The role of exercise physical activity in varying the total energy expenditure in healthy Japanese men 30 to 69 years of age

This study was designed to examine 1) the role of exercise physical activity (EPA), and then 2) physical fitness and body composition upon variation of the total energy expenditure (TEE) in healthy Japanese men aged 30 to 69 y (n = 40). EPA and TEE were assessed over 14 d using an accelerometer and a doubly labeled water (DLW) method, respectively. Basal metabolic rate (BMR) was measured after 10 h fasting on the morning of the day of DLW dosing. Physical activity-induced energy expenditure (PAEE) was calculated by subtracting BMR and diet-induced thermogenesis (DIT = 101 TEE) from TEE. EPA was subdivided into three intensities: low, moderate and high and the accumulated duration (time expressed in minutes) of each of these was calculated. Body composition and physical fitness (VO2max) were determined using an underwater weighing method and a treadmill exercise test, respectively. BMR (mean +/- SD: 1,459 +/- 181 kcal/d) declined significantly with age (r = -0.37. p < 0.05), but PAEE (946 +/- 320 kcal/d) and TEE (2,672 +/- 369 kcal/d) did not. A multiple stepwise regression analysis was used to develop an empirical model that relates energy expenditure measured by the DLW (TEE) to age, height, body mass index, FM, FFM, percentage body fat, VO2max, and accumulated duration spent for low-, moderate-, and high-intensity EPA. The results revealed that FFM and high-intensity EPA were identified as important determinants of TEE and accounted for 51%. We may therefore conclude that 1) high-intensity EPA appears to be relevant in determining TEE, especially among active individuals, and 2) body composition was more important than physical fitness in determining TEE in this population.     

Total daily energy expenditure among middle-aged men and women: the OPEN Study

BACKGROUND: Few large doubly labeled water (DLW) studies have provided an objective measure of total energy expenditure (TEE) in free-living men and women. The committee that developed the 2002 Dietary Reference Intake (DRI) estimated energy requirements (EER) noted that DLW studies in adults aged 40 to 60 y were limited. OBJECTIVE: We aimed to describe TEE and physical activity energy expenditure in middle-aged men and women by sex, age, menopausal status, and level of obesity, and to compare TEE to the DRI EER. DESIGN: TEE was measured by the DLW method in 450 men and women aged 40-69 y from the Observing Protein and Energy Nutrition Study. Resting metabolic rate was estimated by use of the Mifflin equation. RESULTS: Unadjusted TEE was lower in women than in men (591 kcal/d); however, when the analysis was adjusted for fat-free mass, women had significantly higher TEE than did men (182 kcal/d). This difference appeared to be due to higher physical activity levels in women (physical activity energy expenditure adjusted for FFM was 188 kcal/d greater in women than in men). Mean TEE was lowest in the seventh decade. TEE from DLW was highly correlated (r = 0.93) with EER from the DRI equations. CONCLUSION: In this population, TEE was higher in women than in men when adjusted for FFM, apparently because of higher physical activity levels in women. There were no significant differences in TEE, FFM, or physical activity levels in women by menopausal status. TEE was inversely associated with age and increased linearly with body mass index. This study corroborates the use of the DRI equations for EER.     

Metabolic effects of mental stress during over- and underfeeding in healthy women.

OBJECTIVE: To assess the short-term consequences of carbohydrate or fat overfeeding or of food restriction on the metabolic effects of mental stress in healthy lean women. RESEARCH METHODS AND PROCEDURES: The effects of a sympathetic activation elicited by mental stress were evaluated in a group of healthy women after standardized isocaloric feeding (ISO) or after a 3-day overfeeding with 40% excess calories as either carbohydrate overfeeding (CHO OF) or fat overfeeding (FAT OF). Oxygen consumption rate (VO(2)) was measured as an index of energy expenditure, and subcutaneous glycerol concentrations were monitored with microdialysis. The same measurements were performed in another group of healthy women after ISO and after a 3-day period of underfeeding with a protein sparing modified fast (UF). RESULTS: In all conditions, mental stress significantly increased heart rate, blood pressure, plasma norepinephrine and epinephrine concentrations, and VO(2), and produced a nonsignificant increase in subcutaneous glycerol concentrations. CHO OF and FAT OF did not alter the effects of mental stress on VO(2) and subcutaneous glycerol concentrations. In contrast, UF increased basal VO(2) but significantly reduced its stimulation by mental stress. UF also enhanced the increase in subcutaneous glycerol concentrations during mental stress. DISCUSSION: UF reduces the stimulation of energy expenditure and enhances lipolysis during sympathetic activation. These adaptations may be involved in mobilization of endogenous fat while limiting weight loss. In contrast, short-term overfeeding fails to alter the sympathetic control of energy expenditure and lipolysis.     

Greater than predicted decrease in resting energy expenditure with age: cross-sectional and longitudinal evidence

OBJECTIVE: To determine whether the age-related decrease in resting energy expenditure (REE) is explained by variations in body composition. DESIGN: In Study 1, adult subjects (20-70 years) from the Quebec Family Study were classified into five different age groups. Body composition was measured by hydrodensitometry to determine fat mass and fat-free mass as predictors of REE. In the youngest group of individuals these predictors were used to plot a reference regression that was then used to predict REE in the other age groups. In Study 2, this issue was investigated in a longitudinal design (6-year follow-up). Subjects were subdivided into three groups and a reference regression was plotted at the beginning of the follow-up and was then used to predict REE 6 years later in the three age groups. SUBJECTS: In Study 1, 627 adults (288 men and 339 women), aged between 20 and 70 years. In Study 2, 191 adults (93 men and 98 women). RESULTS: In Study 1, measured REE was 329, 302, 528 and 636 kJ/day (P < 0.0001) below predicted REE at 34, 44, 54 and 64 years, respectively. In Study 2 the most marked deviation from predicted REE in response to the 6-year follow-up in men was observed in young adults (-548 kJ/day, P < 0.001) while in women, the largest deviation occurred later in life (-720 kj/day, P < 0.001). CONCLUSION: Aging is accompanied by a decrease in REE that is significantly greater than what is predicted by variations in body composition. This decrease may reach a mean level of about 500-800 kj/day.     

Effect of 12 weeks' light-moderate underfeeding on 24-hour energy expenditure in normal male and female subjects

The effect of 12 weeks' light-moderate underfeeding on the 24-h energy expenditure of a fixed physical activity programme was studied in six male and six female subjects. During a control period of 2 weeks, measurements were made of 24-h energy expenditure by direct calorimetry, the lean and fat body masses and the subjects' habitual energy intakes. The average body weight was 107 per cent of ideal, and did not change significantly during the control period. The subjects were asked to continue to record their daily food intake while reducing it by 25 per cent and to continue their daily activity habits during a period of 12 weeks. The mean change in body weight was -2.9 kg with an average change in body energy content of -66 MJ. The 24-h energy expenditure was measured three times during the period, ie, after 4, 8 and 12 weeks from the start of the decreased energy intake, and found to be practically the same as the control value, ie, with average differences (s.d.) of -0.2(3.9), -0.8(5.7) and +0.6(4.2) per cent from the control value. In the six subjects who had the largest loss of body weight, this was found to be 5.0 kg, and the mean differences (s.d.) in energy expenditure were found to be -1.0(3.4), 0.0(5.6) and -0.6(3.9) per cent, respectively, from the control value. A significant part of the between-subjects variation in the differences from the control value is due to random measurement error and it is concluded that a loss of body energy content of the magnitude reported here, and due mainly to a reduced food intake, does not result in a significant increase in the efficiency of energy conversion, ie, in metabolic adaptation.     

Normal value of resting energy expenditure in healthy neonates

OBJECTIVE: We investigated the value of resting energy expenditure (REE) in healthy neonates and evaluated the impact factors on REE. METHODS: One hundred eighty healthy neonates (95 boys and 85 girls) with birth weights above 2500 g were measured by indirect calorimetry, and the effect of birth weight evaluated. Measured and predicted REEs were compared, and the effects of sex and delivery method on REE were examined in 154 newborn infants with birth weights of approximately 2500 to 4000 g. RESULTS: Birth weight had a significant effect on REE. There was a negative relation between REE and birth weight (r = -0.289). The REEs of newborn infants weighing more than 4000 g were statistically lower than those of infants weighing 2500 to 4000 g (44.5 +/- 5.9 versus 48.3 +/- 6.1 kcal x kg(-1) x d(-1), P = 0.01). The measured and predicted REEs of 154 newborn infants were 48.3 +/- 6.1 and 54.1 +/- 1.1 kcal x kg(-1) x d(-1), respectively. There was a significant difference between the two values. Sex and delivery methods had no effect on REE in healthy neonates. CONCLUSIONS: The value from the predicted equation is not suitable for neonatal energy supplementation in clinical practice. The normal REE value for healthy neonates with birth weights of 2500 to 4000 g is 48.3 +/- 6.1 kcal x kg(-1) x d(-1).     

Energy-intake restriction and diet-composition effects on energy expenditure in men

Eight men were fed at maintenance for 2 wk, followed by 4 wk at 50% of maintenance, then 1 wk at maintenance. The diets were formulated to contain either 40% or 20% of energy from fat. Daily energy expenditure (24-h EE) was determined by indirect calorimetry at the end of the 2-wk maintenance period; on days 1, 7, and 28 of reduced energy intake; and on days 1 and 7 of refeeding. During the reduced-energy period, body weight decreased from 96.6 to 91.5 kg and body fat decreased from 30.4% to 27.7%. There were no significant differences in 24-h EE or energy requirements per unit body weight due to diet composition or weight loss. Maintenance metabolizable-energy (ME) requirement averaged 31.0 kcal/kg body wt. Overall, the efficiency of ME use relative to body stores was 0.87 and was greater for high-fat than for low-fat diets. There was some evidence of an increase in the efficiency of energy use of body stores after weight loss. Substrate use reflected diet composition and energy-balance status independent of changes in body composition.     

Activity pattern and energy expenditure due to physical activity before and during pregnancy in healthy Swedish women

Human pregnancy is associated with increased requirements for dietary energy and this increase may be partly offset by reductions in physical activity during gestation. Studies in well-nourished women have shown that the physical activity level (PAL), obtained as the total energy expenditure (TEE) divided by the BMR, decreases in late pregnancy. However, it is not known if this decrease is really caused by reductions in physical activity or if it is the result of decreases in energy expenditure/BMR (the so-called metabolic equivalent, MET) for many activities in late pregnancy. In the present study activity pattern, TEE and BMR were assessed in twenty-three healthy Swedish women before pregnancy as well as in gestational weeks 14 and 32. Activity pattern was assessed using a questionnaire and heart rate recording. TEE was assessed using the doubly labelled water method and BMR was measured by means of indirect calorimetry. When compared to the pre-pregnant value, there was little change in the PAL in gestational week 14 but it was significantly reduced in gestational week 32. Results obtained by means of the questionnaire and by heart rate recording showed that the activity pattern was largely unaffected by pregnancy. The findings support the following conclusion: in a population of well-nourished women where the activity pattern is maintained during pregnancy, the increase in BMR represents approximately the main part of the pregnancy-induced increase in TEE, at least until gestational week 32.     

Total energy expenditure and physical activity level in healthy young Swedish children 9 or 14 months of age

OBJECTIVES: To measure total energy expenditure (TEE) and total body water (TBW) in healthy Swedish children 9 or 14 months of age. To compare their TEE with current recommendations for energy intake. To define their body composition and relate this to energy expenditure. DESIGN:: Children were investigated at 9 or 14 months. The following variables were measured: TEE and TBW (by the doubly labelled water method), weight and length. Total body fat (TBF), sleeping metabolic rate, activity energy expenditure and physical activity level (PAL) were calculated. SUBJECTS: Thirty infants 9 months of age and 29 children 14 months of age. RESULTS:: TEE was 323+/-38, 322+/-29, 313+/-23 and 331+/-28 kJ/kg/day in 9-month-old girls, 9-month-old boys, 14-month-old girls and 14-month-old boys, respectively. At 9 months of age girls and boys contained 29.6+/-4.8 and 29.7+/-4.5% TBF, respectively. At 14 months the corresponding figures were 29.1+/-4.3 and 28.2+/-4.3%. There was a significant negative relationship between PAL and %TBF (r=-0.81, P<0.001, n=59). CONCLUSIONS: Measured TEE plus calculated energy cost of growth confirm previous estimates that the physiological energy requirements of children 9 and 14 months of age are 15-20% lower than current recommendations for energy intake. One possible interpretation of the relationship between PAL and %TBF is that children with a high TBF content are less physically active than children with less TBF. However, this relationship needs further studies.     

Physical activity and cause-specific mortality in men: further evidence from the Whitehall study

Reports of studies relating physical activity to stroke and cancer sub-types indicate inconsistent findings. Some are hampered by low statistical power, owing to a low number of events, and a failure to adjust for potential confounding variables. The purpose of this study was to relate physical activity to 12 mortality endpoints in a prospective cohort study of 11,663 men aged 40–64 years who responded to an enquiry about travel activity during a baseline medical examination conducted between 1967 and 1969. During 25 years of follow-up there were 4672 deaths. Travel activity was inversely related to mortality attributable to all-causes, coronary heart disease, respiratory disease and lung cancer, whereas the association with stroke was positive. There was evidence for attenuation of some of these associations on adjustment for potentially confounding variables. Our simplistic measure of physical activity may, in part, explain the weak associations seen.     

Predicting total energy expenditure from self-reported dietary records and physical characteristics in adult and elderly men and women

BACKGROUND: Energy requirements and nutrient intakes are commonly estimated from self-reported dietary records, but such estimation has proven to be unreliable. When energy intakes determined from dietary records are compared with energy expenditures measured with the use of doubly labeled water, the former consistently underestimate energy requirements and have a high degree of variability. OBJECTIVE: The objective of this study was to reduce the bias and variability of self-reported dietary records through the use of stepwise multiple regression analysis to develop models that relate energy expenditure measured with the use of doubly labeled water to energy intake from dietary records, sex, and fat-free mass (or weight and height). DESIGN: Data from 54 healthy adult men and women were used to develop these models. RESULTS: Fat-free mass, energy intake, and sex accounted for 86% of the variability in energy expenditure, whereas energy intake, sex, height, and weight accounted for 83%. When the model relating fat-free mass, energy intake, and sex to energy expenditure was tested on published data, it reduced the bias and variability of self-reported dietary records from -17 +/- 27% to 3 +/- 16%. When the model relating energy intake, sex, weight, and height to energy expenditure was tested on published data, it reduced the bias and variability of self-reported dietary records from -19 +/- 25% to -0.3 +/- 19%. CONCLUSION: Results from this study indicate that a simple relation can be used to correct self-reported dietary records to estimated energy requirements.