ASSESSMENT OF ENERGY EXPENDITURE (2024)

ASSESSMENT OF ENERGY EXPENDITURE

THREE-DAY ACTIVITY RECALL

An individuals total energyexpenditure (TEE) comprises the number of calories expended during physicalactivity, thenumber of calories needed to digest food (DIT) and the number of calories expendedduring sleep (BMR).

Physical Activity Energy Expenditure

Any hopeof changing the pattern and quality of daily physical activity must bepredicated on an accurate appraisal of the daily energy expenditure.Maintenance of body weight and body composition is controlled by a relativelysimple interaction of diet and physical activity (although each itself isextremely complex). Diet corresponds to the fuel for the system, or ÒinputÓ(refer to homework assignment #1) and physical activity is the expenditure ofthe fuel, or ÒoutputÓ. When the input does not equal output, the system is outof balance and energy (in the form of body weight) is not maintained. Forexample, if your average daily diet consists of 2130 kCal, but your averagedaily energy expenditure is only 1880 kCal, then on any day you would be takingin 250 more kCals than you are expending. That may not seem like much (about 3cookies), but over time calories add up. In two weeks you would have expended3500 kCals less than you have eaten. That is approximately equal to one poundof fat. If you continue on the same diet and physical activity pattern for awhole year, you will probably weigh nearly 26 lbs heavier than if you were incaloric balance.

Similar to theaccuracy of dietary surveys, physical activity diaries usually estimate totalenergy expenditure within 10% of your true energy expenditure. Before recordingyour daily physical activity, you should once again become familiar withÒhonestÓ calorie counting. Your accuracy will depend on your correct recordingof activity and duration. For the physical activity diary, you will onlyrequire three things: 1) a watch, 2) a small pad, and 3) a pen or pencil.

Diet Induced Thermogenesis (Thermic Effect of Food)

In healthyindividuals, consumption of food temporarily increases metabolism. This iscalled obligatory thermogenesis and results from the energetic processes ofdigestion, absorption, and assimilation of nutrients by the body. Generally,DIT reaches a maximum within an hour of eating a meal and ranges between 10-35%of the total calories consumed during the meal. However, interpersonalvariability is great, and DIT for any individual depends on both the quantityand composition of food eaten.

For the purpose ofthis assignment, we will disregard calculations of the DIT.

Basal (Resting) Metabolic Effect

You spend considerable time during the daysleeping (or resting quietly). The energy expenditure (or metabolic rate)during sleep is referred to as your Basal Metabolic Rate or BMR, and isproportional to the body surface area (BSA) expressed as meters squared (m²).The BMR is typically expressed as kCal per meter squared body surface area perhour (kCal/m²/h). It can also be expressed as kCal expended per min,or per hour. For many individuals the BMR contributes the greatest amount tothe total energy expenditure (TEE).

In this assignment you will estimate your basalmetabolic rate (BMR) from your body surface area, which is a function of yourstature (height) and body mass (weight.)

Determining Total Energy Expenditure

Step 1. Determine daily pattern of energy expenditure,including such minimal daily requirements as sleeping (BMR), eating, sitting(sleeping) in class, bathing, and voluntary physical activity. An activityprofile can be constructed by keeping a daily log for three daysof the actual time allotted to the various activities that represent your usualpattern of activity. To illustrate the procedure, Table 1 shows a fairlydetailed activity profile for a college professor during a typical day ofsummer vacation. This record includes a description of the activity, itsduration, and the calories expended during the activity. [Tables 2, 3, and 4are activity logs for you to use, if you wish.]

Step 2. You need to have an estimate of your caloricexpenditure during sleep (BMR). Determine BMR from body surface area (BSA, m²), as follows:

a) BSA (m²)= 0.20247 x Stature^0.725 x Body Mass^0.425

Example

Male:stature, 1.778 m (177.8 cm; 70 in); body mass, 75 kg (165.3 lb)

BSA= 0.20247 x stature^0.725 x body mass^0.425

BSA= 0.20247 x 1.778^0.725 x 75^0.425

BSA= 0.20247 x 1.51775 x 6.2647

BSA= 2.055 cm²

[NOTE:it is also possible to estimate BSA using the data in figure 14-7 of your text]

(b) Determine Basal MetabolicRate (BMR) from BSA

The BMR (in kCal¥min^-1) can be calculated formen and women using the following equations:

MEN: BMR (kCal¥min^-1) = (38 x BSA,m²)Ö 60

WOMEN: BMR (kCal¥min^-1) = (35 x BSA,m²)Ö 60

Step 3. Determine the energy expenditure in kCal¥min^-1for each of the activities listed in your profile. For sleep use the BMR computed above. To obtain calorievalues for different physical activities you can refer to the appendix in yourstudy guide or consult various web pages.

Step 4. Multiply the tabled energy expenditure values by the number of minutesspent in each activity.

Step 5. Sum the total energy expenditure for each activity,including the value for sleep, to arrive at your total energyexpenditure for the day.

Step6. Repeat steps 2‑5 for each ofthree days. Obtain the average daily energy expenditure for the three dayperiod by summing the totalcalories expended over the three day period and dividing by 3.

HOW TO INTERPRET YOUR AVERAGE DAILY ENERGY EXPENDITURE

There is no standard for thenumber of calories you should expend during a day. Many factors are involved,including body size, age, gender, and most importantly your level of physicalactivity. The average daily energy expenditure is 3000 kcal for men and 2100kcal for women between the ages of 19 and 22 years. If you are not gaining orlosing body weight, then your energy expenditure should equal your energyintake (determined in assignment #1).

Assignment

Put your name, an ID number (ofyour choice), your e-mail address and name of this assignment on the firstpage. On subsequent pages do not put your name, only our ID number.

Do the following:

1.Prepare three(3) daily activity logs similar to table 1. Use 3 typical days of the week(perhaps 2 weekday and 1 weekend day). Use the logs provided, or make yourown).

2.Show all yourcalculations; including calculations for BSA.

Answer the following questions:

1.Compare yourcaloric expenditure with your caloric intake from assignment #1. Present and interpretany differences that you find (make a table or graph illustrating thesedifferences). Why are there differences? Be specific.

2.Based on yourresponse to #1 above, do you expect to lose or gain weight over the next 3months if you maintain the same level of caloric intake and expenditure?Explain your answer. Be very specific.

3.What specificchanges do you need to make in your daily food consumption and/or daily energyexpenditure for you to achieve your ideal body weight (you will have to choosean ideal weight you would like to achieve to answer this question.) How long(be specific in terms of number of days, weeks or months) will it take you toreach your ideal body weight?

4.Discuss whatyou discovered in this lab experience. How might this affect the way you eatand exercise in the future?

NOTE:

¯Your reportwill be at least (a minimum) 4 pages long [Table 1 (3 pages- at least one pagefor each day); Answers to questions]. The report can be longer if the spiritmoves you.

Table 1. Detailedrecord of physical activity for one day for a university professor.

Table 2. Activity Log

Table 3. Activitylog.

Table 4. Activitylog.