1. Age:
Energy expenditure varies with lean body mass,
which varies with age. The highest rate of energy expenditure per kg body
weight occurs during infancy and childhood. In adults, energy expenditure
declines about 2% because of the decline in lean body mass.
Energy expenditure varies with lean body mass,
which varies with age. The highest rate of energy expenditure per kg body
weight occurs during infancy and childhood. In adults, energy expenditure
declines about 2% because of the decline in lean body mass.
2. Sex: Differences in body composition between men and
women occur as early as the first few months of life. The differences are
relatively small until the child reaches age 10. During adolescent, body
composition changes radically. Men develop proportionately greater muscle mass
than women, who deposit fat as they mature. Consequently energy expenditure
differs by as much as 10%
women occur as early as the first few months of life. The differences are
relatively small until the child reaches age 10. During adolescent, body
composition changes radically. Men develop proportionately greater muscle mass
than women, who deposit fat as they mature. Consequently energy expenditure
differs by as much as 10%
3. Growth: Human growth is mostly pronounced during the
growth spurts that take place before birth and during infancy and puberty.
Kcals required for per kg body weight are highest during these growth spurts,
because the kilocaloric cost of anabolism is greater than the kilocaloric cost
of catabolism.
growth spurts that take place before birth and during infancy and puberty.
Kcals required for per kg body weight are highest during these growth spurts,
because the kilocaloric cost of anabolism is greater than the kilocaloric cost
of catabolism.
4. Body
size: A tall individual
uses more energy because he or she has a greater skin surface through which
heat is lost than does a shorter person. A shorter person also has less muscle
tissues or lean body mass than a taller person. In proportion to total body
weight, the infant has a large surface area, loses more heat through the skin
and therefore has a proportionately high energy expenditure.
size: A tall individual
uses more energy because he or she has a greater skin surface through which
heat is lost than does a shorter person. A shorter person also has less muscle
tissues or lean body mass than a taller person. In proportion to total body
weight, the infant has a large surface area, loses more heat through the skin
and therefore has a proportionately high energy expenditure.
5. Genetics:
Energy expenditure is strongly influenced by
individual genetic patterns. Each person seems to be programmed with a need to
burn a certain number of kcals to maintain energy balance.
Energy expenditure is strongly influenced by
individual genetic patterns. Each person seems to be programmed with a need to
burn a certain number of kcals to maintain energy balance.
6. Climate: This affects energy expenditure because kcals are
needed to maintain body temperature. This fact pertains to extreme differences
in external in external temperature, whether cold or hot. In the United States
and Canada, most people do not need to eat more kcals during colder months
because the people usually protect themselves from external cold and shivering
which causes an increase in energy expenditure by wearing warm clothes.
needed to maintain body temperature. This fact pertains to extreme differences
in external in external temperature, whether cold or hot. In the United States
and Canada, most people do not need to eat more kcals during colder months
because the people usually protect themselves from external cold and shivering
which causes an increase in energy expenditure by wearing warm clothes.
Calculation of energy expenditure (approximate
energy cost of various activities)
energy cost of various activities)
|
Activity
|
Kcal/kg/hr
|
Activity
|
Kcal/kg/hr
|
|
Aerobics
(heavy) |
8.0
|
Racquet
ball (social) |
8.0
|
|
Aerobics
(medium) |
5.0
|
Roller
staking |
5.1
|
|
Aerobics
(light) |
3.0
|
Running/jogging
(10m/hr) |
13.2
|
|
Backpacking
|
9.0
|
Downhill
skiing (10m/hr) |
8.8
|
|
Basketball
|
10.0
|
Sleeping
|
1.2
|
|
Cycling
(5.5 m/hr) |
3.0
|
Swimming
(0.25 m/hr) |
4.4
|
|
Bowling
|
3.9
|
Tennis
|
6.1
|
|
Calisthenics
(heavy) |
8.0
|
Volleyball
|
5.1
|
|
Calisthenics
(light) |
4.0
|
Walking
(2.5 m/hr) |
3.0
|
|
Canoeing
(2.5m/hr) |
3.0
|
Walking
(3.75 m/hr) |
4.0
|
|
Cleaning
(female) |
3.7
|
Water
skiing |
7.0
|
|
Cleaning
(male) |
3.5
|
Weight
lifting (heavy) |
9.0
|
|
Cooking
|
2.8
|
Weight
lifting (light) |
4.0
|
|
Cycling
(13 m/hr) |
9.7
|
Window
cleaning |
3.5
|
|
Dressing/showering
|
1.6
|
Waiting
(sitting) |
1.7
|
|
Driving
|
1.7
|
|
|
|
Eating
|
1.4
|
|
|
|
Food
shopping |
3.6
|
|
|
|
Football
|
7.0
|
|
|
|
Golf
|
3.6
|
|
|
|
House
back riding |
5.1
|
|
|
|
Jogging
(medium) |
9.0
|
|
|
|
Ice
skating (10 m/hr) |
5.8
|
|
|
|
Lying
(at ease) |
1.3
|
|
|
