What makes up total energy expenditure

What is your BMR? Basal Metabolic Rate is the number of calories required to keep your body functioning at rest. BMR is also known as your body's metabolism; therefore, any increase to your metabolic weight, such as exercise, will increase your BMR. To get your BMR, simply input your height, gender, age and weight below.

What is the smallest component of total energy expenditure? It is, with basal metabolic rate and activity induced thermogenesis, one of the three components of daily energy expenditure.

What is a normal resting energy expenditure? Resting energy expenditure REE. How do you calculate energy cost of physical activity? For example, suppose you weigh lbs and you run at a pace of 7 minutes per mile for 30 minutes. The energy expenditure value of running at 7 minutes per mile is 0. Therefore, the total energy cost of the workout is 0. What is human thermogenesis? Thermogenesis is defined as the dissipation of energy through the production of heat and occurs in specialised tissues including brown adipose tissue and skeletal muscle.

What is direct calorimetry? First look at the percentage of body fat. Which would be calories. So calories a day have to come from carbohydrates. Now divide that by 4 and daily carbohydrates is grams a day.

Now we divide calories by 9 as there are 9 calories in one gram of fat and we get 75 grams of fat. This macronutrient goal is only a starting point for this client. Creating a specific macronutrient plan can be a great way of guiding the right client to their goals. But in our experience most people do not need macros as they are difficult to track and can be relatively confusing.

Instead most people just need to practice certain healthy behaviors that are the foundation of a healthy lifestyle. Learn how to create these healthy lifestyle practices and coach your clients to their nutritional goals in our free coaching course, the Professional Coaching Blueprint. But in order to count calories or macros, one needs to first figure out their TDEE. Determinants and effects of physical activity cannot always be separated. There is a complicated interaction between physical activity and body weight.

Body movement requires energy as produced by muscles. Thus, there is an interaction between physical activity, body weight, body composition, and energy expenditure. To move, one uses muscles and energy as stored in body fat. Excess weight in heavier subjects usually implicates excess body fat, limiting weight-bearing activities like running. In addition to body weight and body composition, physical activity is a function of predisposition, age, and environment.

There typically are those that are always on the move and those you cannot get on the move. Additionally, physical activity is a function of physical capacity as affected by energy supply and disease.

The current chapter comprises methods for the measurement of physical activity, followed by sections on determinants and effects of physical activity, with a special focus on the doubly labeled water method. The doubly labeled water method is a method of indirect calorimetry that was introduced for human use about 30 years ago Schoeller and Van Santen, The principle of the method is that after a loading dose of water labeled with the stable isotopes of 2 H and 18 O, 2 H is eliminated as water, while 18 O is eliminated as both water and carbon dioxide.

The difference between the two elimination rates is therefore a measure of carbon dioxide production Figure 1. The bicarbonate pool consists largely of dissolved carbon dioxide, which is an end product of metabolism and passes in the blood stream to the lungs for excretion.

The rate constants for the disappearance of the two isotopes from the body are measured by mass spectrometric analysis of samples of a body fluid, blood, saliva, or urine. Principle of measurement of carbon dioxide production with doubly labeled water 2 H 2 18 O. After administration of water labeled with heavy oxygen 18 O and heavy hydrogen 2 H , the two isotopes mix with the body water, where 18 O exchanges with CO 2 in the bicarbonate pools as well.

The method is developed after the discovery in that the oxygen atoms in the body water and bicarbonate pools are in equilibration. The method was initially used for studying energy metabolism of small animals in the wild. You capture an animal, administer the dose of labeled water, release the animal and then recapture it after an appropriate interval to assess the rate at which the isotopes disappear from the body.

One of the first such studies involved measuring the energy cost of a kilometer flight by trained racing pigeons. It was not until before the method was first used in people. The reason is that 18 O-water is expensive and a human requires a much higher dose than a bird. The isotope is not substantially cheaper now, but isotope ratio mass spectrometers have become so sensitive that the method can now work with much smaller doses of isotope.

Presently, the method is frequently used with people in several centers. The method is safe to use in humans as the water is labeled with stable isotopes, 18 O and 2 H, at low abundances. Both 18 O and 2 H are naturally occurring isotopes, which are present in the body prior to the administration of doubly labeled water.

As such, tracer studies depend not on measurement of isotopes concentration, but rather on concentrations in excess of natural abundance or background isotope concentrations. The nominal natural abundances of 18 O and 2 H are and ppm, respectively. Typical doses of doubly labeled water only produce excess isotope abundances of — and — ppm for 18 O and 2 H, respectively. The doubly labeled water method can be used to measure carbon dioxide production and hence energy production in free-living subjects for periods of some days to several weeks.

The optimal observation period is 1—3 biological half-lives of the isotopes. The biological half-life is a function of the level of the energy expenditure. The optimal observation interval ranges between 3 days for highly active subjects or prematures, respectively, and about 4 weeks in elderly sedentary subjects.

An observation starts by collecting a baseline sample. Subsequently the isotopes equilibrate with the body water and the initial sample is collected. The equilibration time is, depending on body size and metabolic rate, for adults h. During equilibration the subject usually does not consume any food or drink. After collecting the initial sample the subject resumes its routines according to the instructions of the experimenter and is asked to collect body water samples blood, saliva, or urine at regular intervals until the end of the observation period.

The method has now been applied in subjects at a wide age range and at different activity levels, from premature infants to elderly and from hospitalized patients to participants in a cycle race. The method needs high precision isotope ratio mass spectrometry, working at low levels of isotope enrichment for money reasons mentioned above Speakman, There is still discussion on the ideal sampling protocol, i.

We prefer a combination of both, taking two independent samples at the start, in the midpoint, and at the end of the observation period. Thus an independent comparison can be made within one run, calculating carbon dioxide production from the first samples and the second samples over the first half and the second half of the observation interval Westerterp et al.

The doubly labeled water method gives precise and accurate information on carbon dioxide production. Converting carbon dioxide production to energy expenditure needs information on the energy equivalent of CO 2 , which can be calculated with additional information on the substrate mixture being oxidized.

One option is the calculation of the energy equivalent from the macronutrient composition of the diet. In energy balance, substrate intake and substrate utilization are assumed to be identical.

In conclusion, doubly labeled water is an excellent method to measure energy expenditure in unrestrained humans in their normal surroundings over a time period of 1—4 weeks. Total energy expenditure TEE consists of four components, i. Sometimes daily energy expenditure is divided into three components, taking SMR and the energy cost of arousal together as energy expenditure for maintenance or basal metabolic rate BMR.

Components of total energy expenditure for an average young adult woman and man as adapted from Westerterp et al. TEE is measured with doubly labeled water as described in the foregoing section.

BMR is measured or estimated with a prediction equation. A measurement of BMR must meet standard conditions of rest, thermoneutrality, fasting, and immobility.

The subject must be awake and the measurement must be performed in a thermoneutral environment to avoid heat production or heat loss for maintenance of body temperature.

To meet the conditions in practice, measurement of BMR is performed in the early morning. Subjects are instructed to fast overnight before the BMR measurement, and to transport themselves to the research center in a vehicle or bus.

They are also asked to avoid exercise the day before testing. Using a ventilated hood system, BMR is measured for 30 min in the supine position. To eliminate effects of subject habituation to the testing procedure, the respiratory measurements during the first 10 min are discarded, and the following 20 min are used to calculate BMR Adriaens et al.

Activity-induced energy expenditure is the most variable component of TEE. A frequently used method is expression of AEE per kg body mass, assuming that expenditure associated with physical activity is weight dependent Schoeller and Jefford, Adjusting AEE for fat-free mass is suggested to remove the confounding effect of sex. BMR is determined by body size and composition, age and gender. A larger subject has higher BMR than a smaller subject. Data on free-living energy expenditure, as measured with doubly labeled water, permit the evaluation of limits to the PAL.

In our site, data were compiled for more than subjects, where energy expenditure was measured over an interval of 2 weeks with the same protocol Westerterp et al. The sample excludes individuals aged under 18 years, or those involved in interventions in energy intake, physical activity including athletic performance, or those that were pregnant, lactating or diseased Table 1.

The sample includes similar numbers of women and men, with a wide range for age, height, weight, and body mass index. Despite the wide variation in subject characteristics, there is a narrow range of the PAL of the subjects Figure 3. Frequency distribution of the value of the physical activity level, total energy expenditure as a multiple of basal metabolic rate, in a group of women closed bars and men open bars , where subject characteristics are presented in Table 1.

TABLE 1. Characteristics of healthy subjects living in Northern Europe, where the physical activity level is measured over 14 days under free-living conditions with doubly labeled water. There is no sex difference in the PAL. The minimum value of 1.

The maximum value of 2. Higher values are difficult to maintain over a long period of time and generally result in weight loss, unless intake is supplemented see also the section 3. The physical activity for sedentary and light activity lifestyles ranges between 1. There are a large number of non-calorimetric techniques for the assessment of physical activity, which can be grouped into three general categories: behavioral observation, questionnaires including diaries, recall questionnaires, and interviews , and physiological markers like heart rate and motion sensors.

Non-calorimetric techniques of estimating habitual physical activity are needed to study the relationship between physical activity and health. The greatest obstacle to the usage of field methods of assessing physical activity in humans has been the lack of an adequate criterion to which techniques may be compared.

The interrelation of various field methods may be of some value, but because there are errors in all methods it is impossible to determine the true validity of any one of them in doing so Montoye et al. However, the doubly labeled water method has become the gold standard for the validation of field methods of assessing physical activity Melanson and Freedson, The indicated alternative for doubly labeled water, to assess the PAL of a subject in daily life, is a doubly labeled water validated accelerometer.

Accelerometers can be used to study patterns of activity in time. Simultaneous measurement of body acceleration and heart rate can give information on physical fitness Plasqui and Westerterp, Behavioral observation and questionnaires, as a self-report method, can be adequately used as an activity-ranking instrument Westerterp, Young children have a low PAL. The increase is reflected in the increase of the PAL from 1.

It seems young children have a lower activity expenditure and PAL because it takes less energy to move around with a lower body weight. Accelerometers provide information on the activity pattern including activity intensity. Despite the constancy of activity energy expenditure adjusted for body weight from childhood to adulthood, the movement pattern clearly differs.

Young children spend more of their active time on high intensity activities Hoos et al. The difference in time spent on high intensity activities between children and adults reflects the different activity patterns among children, which are characterized by short, intermittent bouts of vigorous activity. Probably because of their lower body weight it is easier for children to perform high intensity activities.

Physical activity of an year subject is on average not different from physical activity in a year subject. After age 50, physical activity generally declines, in women as well as men, resulting in a mean PAL of about 1. A PAL of 1. At age 90, one does not go out very often anymore.

The activity pattern of elderly subjects is characterized by low intensity activities Meijer et al. There is a limited number of exercise training studies where the PAL was measured with doubly labeled water, before and at the end of the training intervention.

Combining the data of the studies by plotting the PAL in a sequence of the age of the subjects, there are some clear observations to make Figure 5. The PAL before training ranges from lower values around 1.

Exercise training induces an increase in physical activity in younger subjects but not in older subjects. The exception is a training study in year subjects; however, in this study training was combined with energy restriction to induce weight loss. In younger subjects, the mean physical activity values reached a ceiling value around 2. No training study reported individual PAL values over 2.

Thus, exercise training induces an increase in physical activity when one is young or middle-aged and eats ad libitum. The physical activity level, total energy expenditure as a multiple of basal energy expenditure, before open bar and at the end of a training program closed bar , for eight studies displayed in a sequence of age of the participants as indicated on the horizontal axis.

The horizontal broken lines denote the average physical activity level of 1. The lack of an effect of exercise training on the physical activity can only be explained by a compensatory reduction of physical activity in the non-training time. Observations with accelerometers have shown imposed exercise training did not influence spontaneous activity in younger subjects so that their total PALs increased Meijer et al. In contrast, elderly subjects compensate for exercise training by a decline in spontaneous physical activity, so that PALs remain unchanged Meijer et al.

A potential explanation for a compensatory reduction of physical activity in the non-training time is a negative energy balance. PAL did not increase when exercise training was combined with an energy-restricted diet Kempen et al. The PAL in elderly subjects might not respond to exercise training because of a limitation through energy intake, as indicated by a study of the effect of age on energy balance Ainsli et al.

Exposing year and year subjects to the same strenuous hill walking activity for 10 days resulted in a similar expenditure of about The PAL reaches a maximum value of 2. However, professional endurance athletes can reach a value around 4.

They are a selection of the population, born to be athletes, training for many years to reach their high level of performance. The training includes exercise and the maintenance of energy balance at a high level of energy turnover. The latter implicates the supplementation of the diet with energy drinks. Some can quietly sit and read for hours while others do not have the perseverance to be quiet. Surprisingly, between subjects variation in physical activity is also large within the identical confined space of a respiration chamber, indicating an effect of predisposition Westerterp and Kester, The mean PAL of the subjects in the chamber was 1.

However, the minimum value was as low as 1. There was a subject with an AEE of 1. Subjects with a relatively low or high PAL in the respiration chamber turned out to be, respectively, relatively sedentary or physically active in free-living conditions as well Figure 6. Further studies, as described below, provided evidence for an important genetic component in the threefold variation in AEE among individuals in the same confined environment of a respiration chamber and the significant relation with PAL in free-living conditions.

Free-living physical activity level plotted as a function of physical activity level in the confined environment of a respiration chamber, with the line of identity dotted and the linear regression line continuous After Westerterp and Kester, The test for a genetic contribution was based on a classic twin design. Intrapair differences in monozygotic twins are due to environmental factors and measurement errors, whereas intrapair differences in dizygotic twins are additionally affected by genetic factors.

Physical activity was measured over two consecutive weeks with a doubly labeled water validated tri-axial accelerometer for the measurement of movement. The PAL was significantly related within twin pairs and the relation was nearly twice as strong within monozygotic than within dizygotic twins. Thus, a large part of the variation in physical activity between subjects can be ascribed to predisposition.