Environmental Engineering Reference
In-Depth Information
Energy requirements
Years
kg
Lifestyle
kJ/day
kcal/day
Man
30-60 70 active
15,400 3,700
Source:
FAO 2001.
All of the body's organs need energy in order to function, and even while sleeping we
consume quite a lot of energy. This minimum expenditure of energy just to stay alive is
known as the basal metabolic rate (BMR). The energy expended in sedentary activities,
such as sitting at a computer and writing these words, is about 1.5 times BMR. More
physically strenuous activities obviously require more energy, up to a few times the BMR
(see
Table 3.3
).
Table 3.3.
Energy required to conduct various activities, expressed as multiples of
the basal metabolic rate (BMR), which in an average adult male is approximately 1,500
kcal/day (6,279 kJ/day)
Lifestyle
BMR multiple
Basal metabolic rate
1
Sleeping
1
Sitting (eating, watching TV, etc.)
1.5
Standing, carrying light loads
2.2
Personal care (dressing, showering)
2.3
Household work
2.8
Walking at varying paces without a load
3.2
Agricultural work (planting, weeding, gathering) 4.1
Low-intensity aerobic exercise
4.2
