Energy expenditure/basal metabolic rate ratios in normal and marginally undernourished Colombian children 6-16 years of age

Measurements of basal (BMR) and resting (RMR) metabolic rates, maintenance (MEE) and total daily energy expenditures (TDEE) have been made in Colombian children 6-16 years of age classified as nutritionally normal (boys, n = 129; girls, n = 72) and marginally undernourished (boys, n = 171; girls, n = 74). TDEE/BMR ratios were calculated for comparison with those suggested by FAO/WHO/UNU (1985) and to provide data for children less than 10 years of age. TDEE was measured in free-living, individually calibrated subjects by the heart-rate method. TDEE/BMR increased significantly with age in boys from 1.60 to 1.84 in control subjects and 1.46 to 1.92 in undernourished boys. There was no significant increase with age in the girls. There were no statistically significant differences between nutritional groups but girls had significantly lower values than boys. There was a greater rate of increase in TDEE than BMR with age and girls spent more time in light activities and less in high level activities than boys.     

Patterns of daily energy expenditure in normal and marginally undernourished school-aged Colombian children

Using minute-by-minute heart rate recording, the pattern of energy expenditure (EE), total daily energy expenditure (TDEE) and energy expenditure in activity (EAC) were measured in 132 boys and 110 girls 6-8, 10-12 and 14-16 years of age during ordinary school days. The children were living under economically deprived conditions in Colombia; 70 boys and 59 girls were classified as having marginal malnutrition of sufficient degree to retard growth and sexual maturation. EE, TDEE and EAC increased with age, were in general less in undernourished than control subjects and less in girls than in boys. The age and nutritional group effects were ascribable to differences in lean body mass (LBM). However, the reduced activity in girls was greater than could be accounted for by differences in LBM and are probably the result of cultural pressures. Thus, at the levels of normal activity encountered during school days, the reduced energy expenditure found in undernourished children can be accounted for by differences in body size.     

Total daily energy expenditure and pattern of physical activity measured by minute-by-minute heart rate monitoring in 14-15 year old Swedish adolescents

OBJECTIVE: To assess total daily energy expenditure (TDEE) and patterns of physical activity among Swedish male and female adolescents and to relate the amount and intensity of physical activity to existing recommendations (energy expenditure equal to or above 12.4 kJ/kg/day or accumulation of 30 min/day in moderate physical activity equal to 4.5 times sedentary energy expenditure or more). DESIGN: TDEE, physical activity level (PAL=TDEE/BMR), energy expenditure (EE) and time spent in different intensities of physical activity were assessed by using minute-by-minute heart rate monitoring in combination with laboratory measured sedentary energy expenditure (SEE) and peak oxygen uptake. SETTING: Department of Physical Education and Health, Orebro University, and Department of Clinical Physiology, Orebro Medical Centre Hospital, Sweden. SUBJECTS: Eighty-two 14-15 y old adolescents (42 boys, 40 girls) from the city of Orebro, randomly selected through a two-stage sampling procedure. RESULTS: TDEE was 12.8 MJ/day and 10.0 MJ/day for boys and girls respectively (P<0.001) and PAL was 1.74 and 1.67 (NS). Forty-four percent and 47%, respectively, of TDEE referred to EE in physical activity, of which 70% for both genders referred to light physical activity (corresponding to <4.5 times SEE). Eleven boys and 14 girls had an EE lower than 12.4 kJ/kg/day and/or did not accumulate 30 min/day in physical activity >/=4.5 SEE. Those (n=20) with the highest PAL values (>2.01 and 1.81, respectively) spent 149 min/day at a >/=4.5 SEE intensity level compared to 40 min/day for those (n=30) with the lowest PAL values (<1.55 and 1.45, respectively). CONCLUSIONS: Swedish adolescent boys and girls are similarly physically active. The major amount of time devoted to physical activity refers to light physical activity. At least thirty percent of adolescents seem not to achieve appropriate levels of physical activity considered to be beneficial for health. SPONSORSHIP: Orebro County Council, The Public Health Committee of Stockholm County Council, Sweducation Foundation.     

Energy intake and expenditure of free-living, pregnant Colombian women in an urban setting.

BACKGROUND: This study examined the components of energy balance in poor, free-living pregnant women living in an urban setting of a developing country. OBJECTIVES: We tested the following hypotheses: 1) energy intake increases in pregnancy and is greater than when nonpregnant and nonlactating (NPNL), 2) basal metabolic rate (BMR) increases in pregnancy and the increase is positively correlated with prepregnancy fatness, and 3) energy expenditure in activity decreases in pregnancy and is lower than in NPNL women. DESIGN: Pregnant women were studied at 14.8 +/- 3.4 (n = 40), 25.0 +/- 3.2 (n = 54), and 34.9 +/- 2.4 (n = 43) wk gestation, and NPNL women at baseline (n = 114) and at 3 (n = 103) and 6 (n = 93) mo. Energy intake was measured by using estimated diet records and energy expenditure by using the flex heart rate method. Time allocation in physical activity was assessed by observation. RESULTS: In pregnant women, body weight, BMR, and energy intake increased but total daily energy expenditure (TDEE) did not change significantly. There were no significant changes in time allocation to selected activities except for lying down. In comparison with NPNL control subjects, women in late pregnancy had higher energy intakes and BMRs. Values for TDEE were not significantly different, but pregnant women expended less energy in activity and allocated more time to 2 energy-saving activities and less time to 2 energy-demanding activities. CONCLUSION: A decrease in energy expenditure in activity and changes in time allocation are important ways in which pregnant women meet the energy demands of pregnancy.     

Free living energy expenditure in post menopausal women before and after exercise training

The aim of the study was to determine the effects of 8 weeks of moderate exercise training, on 24-hour free living energy expenditure in previously sedentary post-menopausal women. The experimental group (EX) included 9 women. Ten non-exercising control subjects (CON) were recruited to undergo pre- and post-testing. Estimated total daily energy expenditure (TDEE), total 24-hour heart beats (HB), total energy intake (TEI), resting metabolic rate, maximal oxygen consumption (VáO2max), body composition, and submaximal heart rate were measured before and after the exercise intervention. Body composition did not change (body fat % in CON 34.0 +/- 4.0% vs. 33.9 +/- 3.6% and EX 34.1 +/- 4.0% vs. 34.0 +/- 3.4%). Mean submaximal heart rate during steady-state exercise in EX was lower after training compared to CON (p < .05); however, VáO2max did not increase significantly (CON 1.96 +/- 0.23 vs. 1.99 +/- 0.24 l L O2/min and EX 1.86 +/- 0.39 vs. 1.94 +/- 0.30 L O2/min). Neither estimated TDEE (CON, 11.6 +/- 2.0 vs. 11.4 +/- 2.78 MJ; and EX 11.4 +/- 3.3 vs. 11.5 +/- 2.5 MJ, pre vs. post, respectively), RMR (CON 134.2 +/- 9.4 vs. 136.9 +/- 15.0 KJ/kgFFM/day, and EX 138.4 +/- 6.4 vs. 140.7 +/- 14.2 KJ/kgFFM/day, pre vs. post, respectively), TEI (CON 7.9 +/- 2.2 vs. 8.2 +/- 2.5 MJ, and EX 9.4 +/-1.6 vs. 8.3 +/- 2.8 MJ), nor HB (CON 110,808 +/- 12,574 vs. 107,366 +/- 12,864 beats, and EX 110,188 +/- 9,219 vs. 114,590 +/- 12,750 beats) change over 8 weeks in either group. These data suggest that a moderate exercise program may not impact on TDEE, RMR, TEI, or HB in previously sedentary, older women.     

Marginal malnutrition in school-aged Colombian boys: metabolic rate and estimated daily energy expenditure

Total daily energy expenditure (TDEE) and energy expenditure in activity (EAc) were estimated in 114 free-ranging, nutritionally normal, and undernourished boys 6-16 yr of age by measuring basal and resting metabolic rates, average daily heart rate while awake, and oxygen consumption and heart rate during exercise on a treadmill. Mean daily heart rates were in the range of exercising heart rates and gave reasonable estimates of TDEE and EAc. TDEE increased with age (p less than 0.001) and was reduced in undernourished boys (p = 0.011). Results indicate that nutritional group differences in TDEE were due to differences in body size. EAc increased with age but did not show significant differences between nutritional groups, indicating that in the marginal malnutrition of school-aged children, reduced growth and associated economy of energy expenditure in locomotion is sufficient physiological adaptation. Peer pressure in school and play activities may interfere with the protective mechanism of reduced activity.     

Influence of dietary intervention on artificially increased activity in marginally undernourished Colombian boys

Studies of the pattern of daily energy expenditure (EE), total daily energy expenditure (TDEE) and energy expended in activity (EAC) have been carried out in 14 nutritionally normal and 19 marginally malnourished, free-living boys 10-12 years of age using the minute-by-minute heart rate recording technique. Measurements were made during an ordinary school day and again about 6 months later under conditions of a summer day-camp where the activity levels were artificially increased by encouragement to participate in supervised sports activities and play. The morning and afternoon activities were separated by a dietary intervention in the form of a hot meal providing approximately 3.2 MJ (760 kcal). In the morning sessions of the day-camp the undernourished boys did not keep up with the control group by increasing their EE. However, for about 2 h following the noon meal, they did increase EE to levels comparable to the control group but again reduced their EE later in the afternoon and earlier than the control subjects. The data show an inability of undernourished boys to increase their activity which is positively affected for a short period by dietary intervention.     

Energy expenditure studies to predict requirements of selected national athletes

A study to predict energy requirements of national athletes, 84 males and 24 females in 9 and 4 different types of sports respectively, were conducted during centralised training. Parameters assessed were anthropometry, 3-day activity pattern and energy cost (kcal/min) of common activities to derive total daily energy expenditure (TDEE). Based on body mass index (BMI), 68 males or 81% and 19 females or 79% of the athletes were classified as normal. The mean body fat content for males and females were 13.8 ± 4.5% and 24.7 ± 5.3%, respectively. The mean daily activity pattern of males and females athletes were similar for light activities (16? hr or 68% of day), for moderate activities (3? hr or 15% of day in male, 4 hr or 17% in females) while moderate to heavy activities related to training were 4 hr (17%) and 3? hr (15%) in males and females, respectively. Energy cost of some common activities ranges from 1.00-3.00 kcal/min in males and 0.84-2.04 kcal/min in females, while values for jogging were 6.60 kcal/min and 5.62 kcal/min in males and females, respectively. The mean TDEE in male ranges from 2938 kcal (12.3 MJ) in boxers (57 kg) to 4861 kcal (20.3 MJ) in weightlifters (110 kg) while the mean TDEE in female ranges from 2099 kcal (8.8 MJ) in athletics (51 kg) to 3098 kcal (13.0 MJ) in basketball (61.4 kg). The calculated physical activity level (PAL) values using measured BMR for males and females athletes ranges from 1.99-2.58 and 1.77-2.34, respectively. In conclusion, the estimated energy requirement for the various sports event studied ranges from 44-55 kcal/kg/day in males and 38-50 kcal/kg/day in female athletes.     

Total daily energy expenditure and activity level in anorexia nervosa.

Clinical reports consistently comment on high physical activity for anorexia nervosa patients but provide few quantitative measurements. To assess activity, total daily energy expenditure (TDEE) by doubly labeled water, basal metabolic rate (BMR), and thermic effect of meals (TEM) were measured in six female outpatients with anorexia nervosa (67% of ideal body weight) and age-, sex-, and height-matched to six control subjects. Anorexia nervosa patients expended more energy as physical activity than did control subjects [0.084 +/- 0.012 vs 0.044 +/- 0.008 MJ/kg body wt, respectively (20.1 +/- 3.0 vs 10.5 +/- 1.9 kcal/kg body wt, respectively), P less than 0.04], although they had a lower BMR [4.17 +/- 0.37 vs 5.52 +/- 0.15 MJ/d, respectively (997 +/- 89 vs 1319 +/- 37 kcal/d, respectively), P less than 0.01]. TDEE and TEM were similar in both groups. There was a reduction in serum triiodothyronine (T3; 1.20 +/- 0.15 vs 2.04 +/- 0.13 nmol/L, respectively; P less than 0.003) and a slight reduction in serum thyroxine (T4); reverse T3, thyrotropin, free T4, serum cortisol, and adrenocorticotropin values were normal. BMR correlated with total body weight and fat-free mass. These results provide quantitative evidence for increased physical activity in anorexia nervosa despite profound underweight and hypometabolism.     

Influence of an interpersonal laboratory stressor on youths' choice to be physically active

OBJECTIVE: To determine whether interpersonal stress reduces youths' motivation to exercise in a laboratory setting. RESEARCH METHODS AND PROCEDURES: Physical activity and sedentary behavior were measured in boys and girls across a control day, after reading children's magazines, and on a stress day, after giving a videotaped speech. For one analysis, children were divided into low (n = 12) and high (n = 13) heart-rate reactivity groups based on changes in heart rate to stress. In a second analysis, children were divided into low and high perceived level of stress based on changes in perceived stress. To determine differences in choice of exercise or sedentary behavior across the control and stress conditions, subjects chose either to exercise for progressively longer periods to earn a monetary reinforcer or to engage in a high-rated sedentary behavior. RESULTS: The choice to exercise was influenced by stress reactivity differently in the stress and control conditions. Low heart-rate reactive children participated in similar (p > 0.50) amounts of exercise on the stress and control days, but high heart-rate reactive children participated in less (p < 0.01) exercise (22.0 +/- 2.5 vs. 26.3 +/- 2.2 minutes) on the stress than control days. When grouped by change in perceived stress, there were no group differences, but subjects exercised longer (p < 0.01) on the control day than the stress day. DISCUSSION: Interpersonal stress decreased exercise in children susceptible to interpersonal stress. Stress-induced alterations in health behaviors may lead to weight gain in children.     

Assessing energy expenditure in cancer patients: a pilot validation of a new wearable device

BACKGROUND: Nutrition problems are common in cancer patients and are frequently due to metabolic derangements. Thus, accurately assessing energy expenditure (EE) is important in planning adequate nutrition support. Indirect calorimetry (IC) represents the gold standard method but is not always available or applicable to all settings. The purpose of this study was to preliminary compare a new wearable device, the SenseWear armband (SWA), to IC in cancer patients. METHODS: Ten (6 M, 4 F) subjects (mean +/- SD: 56.6 +/- 13.3 years) affected by newly diagnosed acute myelogenous leukemia, undergoing induction chemotherapy, were prospectively enrolled. Resting EE (REE) was measured simultaneously by SWA and IC on admission (day 0) and at discharge (end). Total daily EE (TDEE) was determined by SWA 4 times during the stay (days 0, 7, 14, and end) and predicted values were calculated according to IC REE estimates (TDEE = IC x correction factor 1.2). RESULTS: Mean length of stay was 27.1 +/- 6.2 days. Bland-Altman plots revealed no significant differences between overall REE estimates (day 0 + end) performed by IC and SWA (mean +/- SD; 1645 +/- 282 vs 1705 +/- 278 kcal/d) and the correlation was high (r = 0.84; p < .0001). SWA TDEE showed a progressive reduction during the stay. No bias was detected between overall SWA TDEE (1799 +/- 153 kcal/d) and IC predicted TDEE (1974 +/- 176 kcal/d), but there was a wide 95% confidence interval (-672; +321 kcal/d). Moreover, the correlation between these values was significant (r = 0.68; p = .001). CONCLUSIONS: SWA seems to provide accurate and reliable estimation of REE and useful information on TDEE also in cancer patients. Its use appears promising. Validation studies on larger samples and different cancer types should be considered.     

Cross talk between physical activity and appetite control: does physical activity stimulate appetite?

Physical activity has the potential to modulate appetite control by improving the sensitivity of the physiological satiety signalling system, by adjusting macronutrient preferences or food choices and by altering the hedonic response to food. There is evidence for all these actions. Concerning the impact of physical activity on energy balance, there exists a belief that physical activity drives up hunger and increases food intake, thereby rendering it futile as a method of weight control. There is, however, no evidence for such an immediate or automatic effect. Short (1-2 d)-term and medium (7-16 d)-term studies demonstrate that men and women can tolerate substantial negative energy balances of < or = 4 MJ energy cost/d when performing physical activity programmes. Consequently, the immediate effect of taking up exercise is weight loss (although this outcome is sometimes difficult to assess due to changes in body composition or fluid compartmentalization). However, subsequently food intake begins to increase in order to provide compensation for about 30% of the energy expended in activity. This compensation (up to 16 d) is partial and incomplete. Moreover, subjects separate into compensators and non-compensators. The exact nature of these differences in compensation and whether it is actually reflective of non-compliance with protocols is yet to be determined. Some subjects (men and women) performing activity with a cost of < or = 4 MJ/d for 14 d, show no change in daily energy intake. Conversely, it can be demonstrated that when active individuals are forced into a sedentary routine food intake does not decrease to a lower level to match the reduced energy expenditure. Consequently, this situation creates a substantial positive energy balance accompanied by weight gain. The next stage is to further characterize the compensators and non-compensators, and to identify the mechanisms (physiological or behavioural) that are responsible for the rate of compensation and its limits.     

The effect of an incremental increase in exercise on appetite, eating behaviour and energy balance in lean men and women feeding ad libitum

The effects of incremental exercise on appetite, energy intake (EI), expenditure (EE) and balance (EB) in lean men and women were examined. Six men (age 29.7 (SD 5.9) years, weight 75.2 (SD 15.3) kg, height 1.75 (SD 0.11) m) and six women (age 24.7 (SD 5.9) years, weight 66.7 (SD 9.10) kg, height 1.70 (SD 0.09) m) were each studied three times during a 16 d protocol, corresponding to no additional exercise (Nex), moderate-intensity exercise (Mex; 1.5-2.0 MJ/d) and high-intensity exercise (Hex; 3.0-4.0 MJ/d) regimens. Subjects were fed to EB during days 1-2, and during days 3-16 they fed ad libitum from a medium-fat diet of constant composition. Daily EE, assessed using the doubly labelled water method, was 9.2, 11.6 and 13.7 MJ/d (P < 0.001; SED 0.45) for the women and 12.2, 14.0 and 16.7 MJ/d (P = 0.007; SED 1.11) for the men on the Nex, Mex and Hex treatments, respectively. EI was 8.3, 8.6 and 9.9 MJ/d (P = 0.118; SED 0.72) for the women and 10.6, 11.6 and 12.0 MJ/d (P = 0.031; SED 0.47) for the men, respectively. On average, subjects compensated for about 30 % of the exercise-induced energy deficit. However, the degree of compensation varied considerably among individuals. The present study captured the initial compensation in EI for exercise-induced energy deficits. Total compensation would take a matter of weeks.     

Simulation of average energy expenditures and related inhalation rates for the U.S. population

Inhalation rates (rVe) for determining intakes of air pollutants generally must be estimated because it is difficult to make direct inhalation measurements in free-standing populations. The key to quantifying rVe is to estimate the oxygen consumption rate (rO2) required to sustain an individual’s total daily energy expenditure (TDEE) and then to convert rO2 to rVe using the ventilatory equivalent for oxygen (VQ). To estimate TDEEs for U.S. population cohorts, nonlinear equations that predict TDEE were developed using data derived from doubly labeled water metabolic studies involving 222 groups with a total of 6,027 subjects. Monte Carlo sampling of lognormally distributed body weights, VQ values, and error terms of the TDEE predictions were then used to simulate average TDEE and rVe for U.S. population cohorts. The maximum TDEE value for males was 13.5 MJ/day, which occurred within the 19–29 year age cohort, and for females it was 10.4 MJ/day at ages 18–19 years. Analyses of the relationship between the body mass index (BMI) and physical activity level (PAL?=?TDEE?÷?resting metabolic rate) showed that PAL is not very sensitive to changes in BMI. The highest daily inhalation rates for males and females were 17 and 13 m³/day, respectively, and estimated breathing rates for active (nonresting) hours were about a factor of two greater than for inactive (sleep/resting) periods. Finally, it was shown that efforts to control obesity in the USA have the potential for reducing inhalation rates due to the decreased oxygen/energy requirements of lower body weights.     

Spontaneous activity responses to exercise in males and females

OBJECTIVE: This study examines the impact of a short-term exercise programme, prescribed on the basis of current exercise recommendations, on energy balance in males and females to assess whether this type of exercise induces compensatory changes in spontaneous activity energy expenditure (SAEE) and energy intake (EI). DESIGN: Individuals were monitored for 16 days, 8 days of habitual physical activity (C) and 8 days when exercise was imposed (E). Total energy expenditure (TEE) was calculated from individual relationships of VO2 and VCO2 to heart rate (HR) records of HR and physical activity obtained during waking hours of the C and E periods and basal metabolic rate (BMR) measurements (Deltatrac System, Datex Instrumentation). Changes in nude body mass (BM) were estimated by using a digital scale (Sartorius AG, Gottigen, Germany). SETTING: Laboratory and free-living. SUBJECTS: Eight lean females (body fat: 17.5+/-4.5%) and eight males of similar percentage body fat participated in this study. All subjects were Caucasian and aged between 20 and 25 years. INTERVENTION: During the E period, a supervised exercise session was conducted every second day, each consisting of a total net energy expenditure of 2092 kJ+BMR at 90% lactate threshold. RESULTS: During the E period, TEE was higher than C in males and females (exercise: 95.2+/-13.9, 78.3+/-15.9 MJ; control: 82.4+/-10.4, 68.8+/-16.7 MJ, respectively; P<0.00; P=0.02). SAEE, calculated as TEE minus the energy expended during exercise, was not significantly different between C (males: 82.4+/-4.8 MJ; females: 68.8+/-7.6 MJ) and E (males: 86.8+/-6.3 MJ; females: 70.0+/-7.2 MJ) periods in either gender. Males showed no change in BM over the C (pre-intervention: 83.4+/-7.2 kg; post-intervention: 83.1+/-6.8 kg) or E (pre-intervention: 83.4+/-6.8 kg; post-intervention: 83.4+/-6.8 kg) periods. Females' BM over the C period did not alter (pre-intervention: 63.3+/-2.8 kg; post-intervention 63.7+/-3.1 kg); however, there was a significant decrease (P<0.00) in BM over the E period (pre-intervention: 63.0+/-2.7 kg; post-intervention: 62.4+/-2.7 kg). CONCLUSION: The exercise programme was achieved in males and females without any impact on SAEE. Therefore, differences between genders in relation to BM reduction can be explained by differences in the EI response to exercise.     

Reproducibility of 24 h energy expenditure measurements using a human whole body indirect calorimeter

Ten female subjects completed two similar experimental procedures (periods 1 and 2) to obtain values of reproducibility of energy intake and 24 h energy expenditure (24hEE) measurements in a whole body indirect calorimeter. The periods consisted of consumption of a provided weight-maintenance diet for 6-8 d, faeces and urine collection during the last 4 d and occupation of the calorimeter during the last 3 d. The daily routine inside the calorimeter simulated a sedentary day in normal life with some physical activity: 8 h sleep, 75 min bicycling and the remaining time spent on sedentary activities. The metabolizable energy (ME) content of the diet (14% energy as protein, 46% energy as carbohydrate, 40% energy as fat) was calculated using food tables. The actual ME intake as well as digestibility and metabolizability of the diet were obtained later by analyses of food, faeces and urine for energy. Three consecutive 24hEE measurements were performed during the stay in the calorimeter in each period. The time interval between the two periods varied from 2 to 24 months. Reproducibility was assessed at group and individual level. Mean digestibility and metabolizability of the diet showed no significant difference between periods. The within-subject coefficient of variation of metabolizability between periods was 1.7%. Mean 24hEE (MJ) over 3 d did not differ between period 1 (8.78 (SD 0.63)) and period 2 (8.73 (SD 0.66)). The within-subject coefficient of variation in mean 24hEE over three successive days between periods was 3.1% but decreased, after deletion of values for subjects who were less adapted to the calorimeter, to 1.9%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of addition of exercise to energy restriction on 24-hour energy expenditure, sleeping metabolic rate and daily physical activity

Body composition, sleeping metabolic rate (SMR), 24-h energy expenditure (24-EE) and daily physical activity were determined in 12 obese women during and after 12 weeks of exercise (4 h per week on 55 per cent of VO2 max) and/or energy restriction (2.9-3.5 MJ/d). Diet(D) and diet-exercise (DE) groups were formed by matching the subjects on their body mass index (BMI, kg/m2; mean 30.3). After 12 weeks no significant differences were shown in loss of weight (D 12.2 and DE 13.2 kg) and loss of fat mass (D 9.4 and DE 10.9 kg). Both groups reduced their SMR (D 29.9 per cent and DE 21.7 per cent) and their metabolic rate during the entire night measured by indirect calorimetry (12-EE) (D 36.4 per cent and DE 28.6 per cent; P less than 0.05). Energy expenditure over 24 h, estimated by means of heart-rate monitoring, was reduced by 22.1 per cent for D and by 19.6 per cent for DE (n.s.). Daily physical activity, which was determined during 5 d using an actometer, was increased after 12 weeks for DE (27 per cent; P less than 0.05) and D (10 per cent; n.s.). The suggestion that a reduction in normal activities of daily life in a diet-exercise group is the explanation for the absence of significant differences in weight and fat loss between a diet-exercise and a diet group is not confirmed in this study. Daily physical activity showed a significantly higher increase for the diet-exercise group than for the diet group, while the decline of SMR and 24-EE tended to be smaller.     

The effect of exercise and improved physical fitness on basal metabolic rate

1. The suggestion that there is a sustained enhancement in metabolic rate after exercise was investigated during the course of a study in which six normal-weight volunteers (three men, three women) took part in a 9-week training programme. Baseline values were assessed in a 3-5 week control period of minimal activity before training. At the end of the study the subjects were capable of running for 1 h/d, 5 d/week. 2. Throughout the entire study the subjects were maintained on a constant diet. Measurement of energy expenditure by the doubly-labelled water (2H2(18)O) method showed that the subjects had an energy imbalance of +3% in the control and -20% at the end of the training period. The subjects were in positive (1.1 (SE 0.2) g) nitrogen balance in the second week of the control, and in negative (-0.6 (SE 0.3) g) N balance in the last week of the exercise period. 3. Over the course of the study maximum oxygen consumption (VO2max) and high-density-lipoprotein-cholesterol levels increased by 30%. Heart rate at rest and when performing a standard step test fell significantly. 4. Body composition was assessed weekly by 40K counting and skinfold thickness measurements, in addition to 2H2 dilution at the beginning and end of the study. Fat-free mass was apparently gained in the early phases of the study, but there was lack of agreement between the different methods of assessing body composition. Changes in body-weight were not significant. 5. Basal metabolic rate (BMR), overnight metabolic rate (OMR) and sleeping metabolic rate (SMR) were measured on three occasions: in the control period, and the beginning and end of the training periods. Average BMR in the control period was 5.91 (SE 0.39) MJ/24 h and was not changed with activity. There were no changes in OMR (5.71 (SE 0.27) MJ/24 h in the control) nor in SMR (5.18 (SE 0.27) MJ/24 h in the control), nor in BMR, OMR or SMR when expressed per kg body-weight, or per kg fat-free mass. 6. These results do not support the suggestions that there is a sustained increase in BMR following exercise that can usefully assist in weight-loss programmes.     

The effect of grape-seed extract on 24 h energy intake in humans

OBJECTIVE: Since grape-seed extract has been shown to stimulate lipolysis in vitro and reduce food intake in rats, we assessed the efficacy of grape-seed extract with respect to energy intake (EI) and satiety. DESIGN: In a randomized, placebo-controlled, double-blind, cross-over study, 51 subjects (age 18-65 y, body mass index 22-30 kg/m2) ate an ad libitum lunch and dinner twice in the University Restaurant for 3 days. Standard breakfasts and snacks were provided. Supplements were taken 30-60 min prior to each meal. RESULTS: In the total study population, no difference in 24 h EI was found between the grape-seed extract and placebo. However, in the subgroup of subjects (n=23) with an energy requirement > or =the median of 7.5 MJ/day, EI was reduced by 4% (DeltaEI 352.1 kJ/24 h, P=0.05) after grape-seed extract compared to placebo treatment. Meanwhile, there were no significant differences in macronutrient composition, attitude towards eating, satiety, mood or tolerance. CONCLUSIONS: Grape seed reduced 24 h EI, with on average 4% in subjects who had an energy requirement > or =7.5 MJ/day, without further effects on satiety, mood or tolerance. These findings suggest that grape seed could be effective in reducing 24 h EI in normal to overweight dietary unrestrained subjects, and could, therefore, play a significant role in body-weight management.     

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.