Many age-related changes that influence energy requirements occur continually throughout the adult life cycle. A decline in BMR with age has been recognized since the studies of Keys, Taylor and Grande (1973), who estimated it at a rate of 1 to 2 percent per decade. Average decreases of 2.9 and 2.0 percent per decade, respectively, for men and women of normal weight (BMI of 18.5 to 25.0 kg/m2) were calculated more recently (Roberts and Dalall, 2001; Food and Nutrition Board/Institute of Medicine, 2002). The decreases were 3.1 and 1.9 percent per decade among overweight men and women, respectively (Roberts and Dalall, 2001). The decline is not linear, and has a suggested breakpoint at about 40 years of age in men and 50 years in women (Poehlman, 1992; Poehlman et al., 1993). The organization of the data in Table 5.10 by decades points to a breakpoint at about 50 years of age for both genders. This decrease in BMR has been explained partly by the reduction in fat-free mass that occurs with ageing, and by changes in the composition of that fat-free mass (Piers et al., 1998). Several studies, however, suggest that even after adjusting for changes in fat-free mass, BMR is 5 percent lower in older persons compared with young adults (Roberts and Dalall, 2001).
On the other hand, body weight tends to increase with age in many societies. For example, there are more overweight men and women (defined as BMI > 25) than people with BMI £ 25 in the database of the United States Academy of Sciences (Table 5.10) (Food and Nutrition Board/Institute of Medicine, 2002). The largest series currently available of TEE and BMR measurements in people 70 to 79 years old involved 150 men and 150 women randomly recruited in two large cities of the United States. Average weight and BMI were 82.4 kg and 27.4 among men, and 70.6 kg and 27.3 among women (Blanc et al., 2001). Overweight and obesity increase BMR and TEE owing to the increase in the fat-free mass needed to carry the extra weight and to the increased energy cost of activities. However, BMR per unit of body weight is reduced in overweight and obese subjects owing to the larger gain in fat mass relative to metabolically active fat-free mass.
Habitual physical activity, and hence TEE, decrease after a given age (Black et al., 1996; Roberts, 1996). However, studies with standardized activity protocols in a whole body calorimeter did not show differences in TEE between young and old adults (Vaughan, Zurlo and Ravussin, 1991; Pannemans and Westerterp, 1995). Furthermore, although maximal oxygen consumption decreases progressively with age (Suominen et al., 1980), some elderly individuals who have remained physically active are able to maintain high levels of energy expenditure, with PAL values as high as 2.48 (Reilly et al., 1993; Withers et al., 1998). This indicates that the age at which TEE and energy requirements start decreasing depends on individual, social and cultural features that promote or limit habitual physical activity among older adults.
Calculation of energy requirements for the elderly based on PAL is highly dependent on the accuracy with which BMR is measured or estimated. For example, the preliminary TEE results - and therefore energy requirements - of 70 to 79 year-old people in a United States study on health, ageing and body composition (Blanc et al., 2001) were 10.1 ± 1.8 MJ/day for men, and 8.0 ± 1.5 MJ/day for women. Based on actual measurements of BMR (men: 5.9 ± 0.1 MJ/day BMR; women: 4.8 ± 0.1 MJ/day BMR), mean PAL was 1.72 among men and 1.68 among women, but using the predictive equations in Table 5.2, PAL would be 1.55 for men and 1.47 for women. The error in prediction may have been associated with the excessive weight of this population group.
In conclusion, energy requirements for older adults and the elderly should be calculated on the basis of PALs, just as they are calculated for younger adults. Therefore, the accuracy with which BMR of older adults can be estimated becomes of primary importance. As more reliable information on BMR of older adults with differing lifestyles, body composition and physical activity becomes available, it may be necessary to revise the predictive equations for this age group in order to make better estimations of their energy requirements. Allowances must be made for population groups who are more or less active at an advanced age, rather than using age as the single cut-off point to define energy requirements for the elderly.
TABLE 5.10
Daily energy expenditure, basal metabolic
rate and physical activity level measured in United States adults
Age |
No. |
Weight |
TEE measured with DLW |
BMR measured individually |
PAL |
||||||
MJ |
kJ/kg |
kcal |
kcal/kg |
MJ |
kJ/kg |
kcal |
kcal/kg |
||||
Men, BMI 18.5-25.0 |
|||||||||||
20-30 |
48 |
70.7 |
12.7 |
180 |
3 047 |
43 |
7.4 |
105 |
1 770 |
25 |
1.75 |
30-40 |
47 |
71.7 |
12.4 |
173 |
2 964 |
41 |
7.0 |
98 |
1 676 |
23 |
1.78 |
40-50 |
22 |
70.6 |
12.8 |
181 |
3 048 |
43 |
7.0 |
100 |
1 683 |
24 |
1.84 |
50-60 |
8 |
73.1 |
10.5 |
144 |
2 513 |
34 |
6.7 |
91 |
1 590 |
22 |
1.60 |
60-70 |
14 |
67.8 |
10.0 |
148 |
2 397 |
35 |
6.2 |
92 |
1 487 |
22 |
1.61 |
70-80 |
30 |
70.0 |
10.1 |
144 |
2 407 |
34 |
6.3 |
89 |
1 497 |
21 |
1.62 |
80-90 |
4 |
67.1 |
7.1 |
106 |
1 700 |
25 |
6.1 |
91 |
1 457 |
22 |
1.17 |
>90 |
6 |
65.6 |
8.1 |
123 |
1 935 |
29 |
5.9 |
90 |
1 415 |
22 |
1.38 |
Women, BMI 18.5-25.0 |
|||||||||||
20-30 |
76 |
59.4 |
10.2 |
171 |
2 428 |
41 |
5.7 |
96 |
1 361 |
23 |
1.79 |
30-40 |
59 |
58.7 |
10.1 |
172 |
2 412 |
41 |
5.6 |
95 |
1 328 |
23 |
1.83 |
40-50 |
8 |
58.2 |
10.2 |
175 |
2 441 |
42 |
5.4 |
93 |
1 300 |
22 |
1.89 |
50-60 |
18 |
59.8 |
9.1 |
153 |
2 182 |
36 |
5.2 |
87 |
1 241 |
21 |
1.75 |
60-70 |
48 |
59.0 |
8.5 |
145 |
2 042 |
35 |
5.1 |
86 |
1 219 |
21 |
1.69 |
70-80 |
14 |
59.0 |
7.9 |
134 |
1 888 |
32 |
5.1 |
87 |
1 229 |
21 |
1.55 |
80-90 |
6 |
51.9 |
5.8 |
111 |
1 382 |
27 |
4.8 |
92 |
1 143 |
22 |
1.21 |
>90 |
9 |
52.2 |
5.7 |
109 |
1 356 |
26 |
4.9 |
94 |
1 168 |
22 |
1.17 |
Overweight men |
|||||||||||
20-30 |
10 |
89.9 |
13.5 |
150 |
3 224 |
36 |
7.8 |
86 |
1 858 |
21 |
1.90 |
30-40 |
53 |
102.4 |
15.5 |
151 |
3 703 |
36 |
8.6 |
84 |
2 046 |
20 |
1.81 |
40-50 |
37 |
94.6 |
14.5 |
153 |
3 465 |
37 |
7.9 |
83 |
1 878 |
20 |
1.88 |
50-60 |
17 |
100.3 |
14.5 |
144 |
3 458 |
34 |
7.8 |
77 |
1 857 |
19 |
1.88 |
60-70 |
30 |
87.8 |
11.9 |
136 |
2 851 |
32 |
7.1 |
80 |
1 687 |
19 |
1.71 |
70-80 |
34 |
84.8 |
11.0 |
129 |
2 624 |
31 |
7.2 |
85 |
1 713 |
20 |
1.55 |
80-90 |
7 |
78.1 |
9.6 |
123 |
2 294 |
29 |
6.5 |
83 |
1 558 |
20 |
1.47 |
>90 |
2 |
77.5 |
7.8 |
101 |
1 863 |
24 |
6.5 |
84 |
1 550 |
20 |
1.29 |
Overweight women |
|||||||||||
20-30 |
33 |
83.4 |
11.4 |
136 |
2 713 |
33 |
6.4 |
77 |
1 536 |
18 |
1.78 |
30-40 |
41 |
83.9 |
11.7 |
139 |
2 794 |
33 |
6.6 |
79 |
1 587 |
19 |
1.78 |
40-50 |
14 |
96.9 |
12.7 |
131 |
3 032 |
31 |
7.1 |
73 |
1 696 |
18 |
1.80 |
50-60 |
29 |
83.3 |
9.8 |
118 |
2 349 |
28 |
5.9 |
71 |
1 409 |
17 |
1.68 |
60-70 |
46 |
78.2 |
8.6 |
110 |
2 061 |
26 |
5.7 |
74 |
1 374 |
18 |
1.52 |
70-80 |
19 |
69.3 |
7.8 |
113 |
1 868 |
27 |
5.2 |
75 |
1 234 |
18 |
1.51 |
80-90 |
6 |
62.8 |
7.3 |
116 |
1 748 |
28 |
5.2 |
82 |
1 233 |
20 |
1.42 |
>90 |
7 |
74.8 |
7.4 |
99 |
1 766 |
24 |
5.6 |
75 |
1 332 |
18 |
1.33 |
Sources: Roberts and Dallal, 2001; Food and Nutrition Board/Institute of Medicine, 2002.
The practice of regular physical activity is associated with the maintenance of adequate body weight, cardiovascular and respiratory health, and fitness,[5] and a lower risk of developing chronic non-communicable diseases associated with diet and lifestyle (Erlichman, Kerbey and James, 2001; WHO, 2000; WHO/FAO, 2002; Pollock et al., 1998; Ferro-Luzzi and Martino, 1996; Schoeller, 1998; WHO, 2002; Erlichman, Kerbey and James, no date; American Heart Association, 2002; IARC, 2002; CDC, 1996; World Cancer Research Fund/American Institute for Cancer Research, 1997; Saris et al., 2003). Consequently, dietary energy recommendations to satisfy requirements should be accompanied by recommendations to perform adequate amounts of physical activity regularly.
There is consensus among experts that a habitual PAL of 1.70 or higher is associated with a lower risk of overweight and obesity, cardiovascular disease, diabetes and several types of cancer (Black et al., 1996; Erlichman, Kerbey and James, 2001; Pollock et al., 1998; Ferro-Luzzi and Martino, 1996; Schoeller, 1998; Erlichman, Kerbey and James, no date; World Cancer Research Fund/American Institute for Cancer Research, 1997; Saris et al., 2003). Therefore, it is particularly important to recommend regular physical activity to populations and individuals with a sedentary lifestyle or one of light activity. Those with moderately or vigorously physically active lifestyles already have a habitual physical activity close to, or higher than, the health-associated PAL threshold of 1.70 times BMR. Recommendations for these individuals should be aimed at the maintenance of that activity level.
5.6.1 Frequency, duration and intensity of physical activity
Table 5.11 summarizes the minimum amounts of exercise, expressed in terms of frequency, duration and intensity, advocated by several organizations to maintain and promote health among adults (WHO/FAO, 2002; Pollock et al., 1998; WHO, 2002; American Heart Association, 2002; IARC, 2002; CDC, 1996; World Cancer Research Fund/American Institute for Cancer Research, 1997; Saris et al., 2003). The conclusions reached in the cited publications can be summarized as follows:
There is consensus that, in order to promote general health, at least 30 minutes of moderate to vigorous activity should be performed, three or more days per week.
Sedentary people and those with low physical fitness levels will benefit from the lower amounts of exercise prescribed in Table 5.11 (i.e. 30 minutes of moderate activity, three days per week). To obtain increased benefits, those with better conditions should exercise longer and/or at a higher intensity (e.g. 60 minutes of moderate or vigorous activity, five or more days per week).
Longer periods of exercise are required to maintain a healthy body weight and to reduce the risk of obesity than are needed to help reduce the risk of chronic diseases such as coronary heart disease and diabetes mellitus.
Sixty minutes of daily exercise have been advocated to increase the PAL of sedentary people to a value of 1.75 or greater, assist in weight maintenance and play a part in the prevention of some types of cancer, especially colorectal and breast cancer.
Any activity that is rhythmic and aerobic in nature, uses large muscle groups and can be maintained continuously is recommended for general health and fitness. Activities that can be practised as part of everyday life are particularly useful. Examples include brisk walking, climbing stairs, cycling, dancing, jogging/running, hiking, low-impact aerobic exercises, swimming, skipping rope, ice/roller skating and various endurance games and sport activities.
Duration is related to intensity. Thus, when ranges are given in Table 5.11 (e.g. 30 to 60 minutes at 50 to 80 percent capacity), lower-intensity activity should be conducted over a longer period of time (i.e. 60 minutes at 50 percent capacity [moderate activity], or 30 minutes at 80 percent aerobic capacity [vigorous activity]).
An activity regimen of moderate- rather than high-intensity exercise is recommended, and total fitness is more readily attained with longer sessions. Consequently, it may be better to suggest activity of moderate intensity for 60 minutes than of high intensity for 30 minutes.
Although longer sessions are generally preferable, their duration may hinder compliance among some people. In these cases it may be appropriate to recommend accumulated bouts of activity for shorter durations throughout the day (e.g. 15 minutes two or four times daily, instead of 30 or 60 minutes once daily).
TABLE 5.11
Minimum frequency, duration and intensity of
physical activity advocated by selected organizations
Organization |
Recommendation |
World Health Organization (WHO, 2002) |
30 minutes of moderate activity every day. |
World Cancer Research Fund/American Institute for Cancer Research (1997) |
30 minutes of vigorous or 60 minutes of moderate activity daily, plus additional 30 to 60 minutes of vigorous activity once a week. |
United States Centers for Disease Control and Prevention (CDC, 1996) |
30 minutes of moderate activity on all or most days of the week. |
American Heart Association (2002) |
30 to 60 minutes of exercise at 50 to 80% aerobic capacity, at least 3 to 4 days per week. |
American College of Sports Medicine (Pollock et al., 1998) |
For cardio-respiratory fitness and body composition: 20 to 60 minutes of continuous or intermittent (bouts of at least 10 minutes) aerobic activity at 55 to 90% maximum heart rate, or at 40 to 85% maximum oxygen uptake, 3 to 5 days per week. For muscular strength and endurance, body composition and flexibility: One set of 8 to 10 exercises, with 8 to 12 repetitions of each exercise, 2 to 3 days per week. |
International Agency for Research on Cancer (IARC, 2002) |
To maintain healthy body weight: 60 minutes moderate activity on all or most days of the week.a For cancer prevention: Substitute moderate for vigorous activity several times per week. |
International Association for the Study of Obesity (Saris et al., 2002) |
To prevent weight regain in formerly obese individuals: 60 to 90 minutes of moderate activity daily, or shorter periods of vigorous activity. To prevent transition to overweight or obesity: 45 to 60 minutes of moderate activity daily, or 1.7 PAL. For children, more activity time is recommended. |
a Endorsed by the joint WHO/FAO Expert Consultation on Diet, Nutrition and the Prevention of Chronic Diseases (FAO/WHO, 2002).
For general populations, particularly those with sedentary occupations, a joint WHO/FAO Expert Consultation on Diet, Nutrition and the Prevention of Chronic Diseases (WHO/FAO, 2002) recently advocated the performance of moderate-intensity activity, such as brisk walking, for a total of one hour per day on most days of the week to help maintain a healthy body weight and reduce the risk of co-morbid diseases associated with overweight. This level of exercise may be considered part of the daily routine of people with occupations entailing moderate or vigorous, energy-demanding physical activity for one or more hours, five or more days per week.
American Heart Association. 2002. Physical activity and cardiovascular health: How much physical activity is enough? www.americanheart.org/presenter.jhtml?identifier=830.
Arciero, P.J., Goran, M.I., Gardner, A.M., Ades, P.A., Tyzbir, R.S. & Poehlman, E.T. 1993. A practical equation to predict resting metabolic rate in older females. J. Am. Geriatr. Soc., 41: 389-395.
Bandini, L.G., Schoeller, D.A., Fukagawa, N.K., Wykes, L.J. & Dietz, W.H. 1991. Body composition and energy expenditure in adolescents with cerebral palsy or myelodysplasia. Pediatr. Res., 29: 70-77.
Black, A., Coward, W., Cole, T. & Prentice, A. 1996. Human energy expenditure in affluent societies: an analysis of 574 doubly labelled water measurements. Eur. J. Clin. Nutr., 50: 72-92.
Blanc, S., Schoeller, D., Bauer, D., Danielson, M.E., Harris, T., Kritchevsky, S.B., Taaffe, D. & Everhart, J. 2001. Free-living energy requirements of the well-functioning elderly: The Health, Aging and Body Composition Study. Paris, First meeting of the International Academy on Nutrition and Aging, June 2001.
CDC. 1996. Physical activity and health. A report of the surgeon general. United States Centers for Disease Control and Prevention (CDC). www.cdc.gov/nccdphp/sgr/chapcon.htm.
Cole. T.J. 2002. The Oxford Brookes BMR database - a reanalysis. Report commissioned by FAO for the joint FAO/WHO/UNU Expert Consultation on Energy in Human Nutrition.
Coward, A. 1998. Contributions of the doubly labelled water method to studies of energy balance in the Third World. Am. J. Clin. Nutr., 68 (suppl.): 962S-969S.
Cruz, C.M., da Silva, A.F. & dos Anjos, L.A. 1999. A taxa metabolica basal e superestimade pelas equacoes preditivas em universitaras do Rio de Janeiro, Brasil. Arch. Latinoam. Nutr., 49: 232-237. de Boer, J.O., van Es, A.J.H., Voorrips, L.E., Blockstra, F. & Vogt, J.E. 1988. Energy metabolism and requirements in different ethnic groups. Eur. J. Clin. Nutr., 42: 983-997.
Erlichman, J., Kerbey, A. & James, P. 2001. Are current physical activity guidelines adequate to prevent unhealthy weight gain? A scientific appraisal for consideration by an Expert Panel of the International Obesity Task Force (IOTF). London, IOTF. 113 pp.
Erlichman, J., Kerbey, A. & James P. (no date). Physical activity and its impact on health outcomes, Paper II: prevention of unhealthy weight gain and obesity by physical activity: An analysis of the evidence.
Ferro-Luzzi, A. & Martino, L. 1996. Obesity and physical activity. In The origins and consequences of obesity, pp. 207-227. Wiley Chichester, Ciba Foundation Symposium 201.
Food and Nutrition Board/Institute of Medicine. 2002. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids. Institute of Medicine of the National Academies. Washington, DC, National Academy Press.
Hayter, J. & Henry, C.J.K. 1993. Basal metabolic rate in human subjects migrating between tropical and temperate regions - a longitudinal study and review of previous work. Eur. J. Clin. Nutr., 47: 724-734.
Hayter, J.E. & Henry, C.J.K. 1994. A re-examination of basal metabolic rate predictive equations: the importance of geographic origin of subjects in sample selection. Eur. J. Clin. Nutr., 48: 702-707.
Henry, C.J.K. 2001. Basal metabolic rate studies in humans: measurement and application. Background document prepared for the joint FAO/WHO/UNU Expert Consultation on Energy in Human Nutrition, 2001.
Henry, C.J.K. & Rees, D.G. 1991. New predictive equations for the estimation of basal metabolic rate in tropical peoples. Eur. J. Clin. Nutr., 45: 177-185.
IARC. 2002. Handbook of cancer prevention. Volume 6: Weight control and physical activity. Lyons, France, International Agency for Research on Cancer (IARC) Press.
Ismail, M.N., Ng, K.K., Chee, S.S., Roslee, R. & Zawiah, H. 1998. Predictive equations for the estimations of basal metabolic rate in Malaysian adults. Mal. J. Nutr., 4: 81-90.
James, W.P.T. & Schofield, E.C. 1990. Human energy requirements. A manual for planners and nutritionists. Oxford, UK, Oxford Medical Publications under arrangement with FAO.
Keys, A., Taylor, H.L. & Grande, F. 1973. Basal metabolism and age of adult man. Metab., 22: 579-587.
Pannemans, D.L.E. & Westerterp, K.R. 1995. Energy expenditure, physical activity and basal metabolic rate of elderly subjects. Br. J. Nutr., 73: 571-581.
Piers, L.S. & Shetty, P.S. 1993. Basal metabolic rates of Indian women. Eur. J. Clin. Nutr., 47: 586-591.
Piers, L.S., Soares, M.J., McCormack, L.M. & ODea, K. 1998. Is there evidence for an age-related reduction in metabolic rate? J. Appl. Physiol., 85: 2196-2204.
Poehlman, E.T. 1992. Energy expenditure and requirements in aging humans. J. Nutr., 122: 2057-2065.
Poehlman, E.T., Goran, M.J., Gardner, A.W., Ades, P.A., Arciero, P.J., Katzman-Rooks, S.M., Montgomery, S.M., Toth, M.J. & Sutherland, P.T. 1993. Determinants of decline in resting metabolic rate in aging females. Am. J. Physiol., 264: E450-E455.
Pollock, M.L., Gaesser, G.A., Butcher, J.D., Despres, J.P., Dishman, R.K., Franklin, B.A. & Ewing-Garber, C. 1998. American College of Sports Medicine Position Stand on the recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults. Med. Sci. Sports Exerc., 30: 975-991.
Prentice, A.M., Leavelesley, K., Murgatroyd, P.R., Coward, W.A., Schorah, C.J., Bladon, P. & Whitehead, R.G. 1989. Is severe wasting in elderly mental patients caused by an excessive energy requirement? Age Aging, 18: 158-167.
Ramirez-Zea, M. 2002. Validation of three predictive equations for basal metabolic rate. Report commissioned by FAO for the joint FAO/WHO/UNU Expert Consultation on Energy in Human Nutrition, 2002.
Ravussin, E., Harper, I.T., Rising, R. & Bogardus, C. 1991. Energy expenditure by doubly labelled water: Validation in lean and obese subjects. Am. J. Physiol., 261: E402-E409.
Reilly, J.J., Lord, A., Bunker, V.W., Prentice, A.M., Coward, W.A., Thomas, A.J. & Briggs, R.S. 1993. Energy balance in healthy elderly women. Br. J. Nutr., 69: 21-27.
Roberts, S.B. 1996. Energy requirements of older individuals. Eur. J. Clin. Nutr., 50 (suppl. 1): S112-S118.
Roberts, S. & Dallal, D.E. 2001. Energy requirements and aging. Energy working paper No. 8R prepared for the joint FAO/WHO/UNU Expert Consultation on Energy in Human Nutrition, 2001.
Saris, W.H., Blair, S.N., van Baak, M.A., Eaton, S.B., Davies, P.S., Di Pietro, L., Fogelholm, M., Rissanen, A., Schoeller, D., Swinburn, B., Tremblay, A., Westerterp, K.R. & Wyatt, H. 2003. How much physical activity is enough to prevent unhealthy weight gain? Outcome of the IASO 1st Stock Conference and consensus statement. Obes. Rev., 4: 101-114.
Schoeller, D. 1998. Balancing energy expenditure and body weight. Am. J. Clin. Nutr., 68 (suppl.): 956S-961S.
Schofield, W.N. 1985. Predicting basal metabolic rate, new standards and review of previous work. Hum. Nutr. Clin. Nutr., 39C (suppl. 1): 5-41.
Schulz, L.O., Alger, S., Harper, I., Wilmore, J.H. & Ravussin, E. 1992. Energy expenditure of elite female runners measured by respiratory chamber and doubly labelled water. J. Appl. Physiol., 72: 23-28.
Soares, M.J., Francis, D.G. & Shetty, P.S. 1993. Predictive equations for basal metabolic rates of Indian males. Eur. J. Clin. Nutr., 47: 389-394.
Soares, M.J. & Shetty, P.S. 1988. Validity of Schofields predictive equations for basal metabolic rates of Indians. Indian J. Med. Res., 88: 253-260.
Stroud, M.A., Coward, W.A. & Sawyer, M.B. 1993. Measurements of energy expenditure using isotope-labelled water (2H218O) during an Arctic expedition. Eur. J. Appl. Physiol., 67: 375-379.
Suominen, H., Heikkinen, E., Parkatti, T., Frosberg, S. & Kiiskinen, A. 1980. Effects of lifelong physical training on functional aging in men. J. Appl. Physiol., 68: 302-308.
Valencia, M.E., Moya, S.Y., McNeill, G. & Haggarty, P. 1994. Basal metabolic rate and body fatness of adult men in northern Mexico. Eur. J. Clin. Nutr., 48: 205-211.
Vaughan, L., Zurlo, F. & Ravussin, E. 1986. Aging and energy expenditure. Am. J. Clin. Nutr., 53: 821-825.
Westerterp, K.R., Saris, W.H.M., Van Es, M. & ten Hoor, F. 1986. Use of the doubly labelled water technique in man during heavy sustained exercise. J. Appl. Physiol., 61(6): 2162-2167.
WHO. 1985. Energy and protein requirements: Report of a joint FAO/WHO/UNU expert consultation. WHO Technical Report Series No. 724. Geneva.
WHO. 1995. Physical status: The use and interpretation of anthropometry. Report of a WHO expert committee. WHO Technical Report Series No. 854. Geneva.
WHO. 2000. Obesity: preventing and managing the global epidemic. Report of a WHO Consultation. WHO Technical Report Series No. 894. Geneva.
WHO. 2002. World Health Day 2002 "Move for Health". Questions and Answers. www.who.int/world-health-day/q_and_a.en.shtml.
WHO/FAO. 2002. Joint WHO/FAO Expert Consultation on Diet, Nutrition and the Prevention of Chronic Diseases. Draft 28 March 2002. Geneva.
Withers, R.T., Smith, D.A., Tucker, R.C., Brinkman, M. & Clark, D.G. 1998. Energy metabolism in sedentary and active 49- to 70-yr-old women. J. Appl. Physiol., 84: 1333-1340.
World Cancer Research Fund/American Institute for Cancer Research. 1997. Food, nutrition and the prevention of cancer: a global perspective. Washington, DC, American Institute for Cancer Research.
[5] The term "fitness"
encompasses cardiorespiratory health, appropriate body composition (including
fat distribution), muscular strength, endurance and flexibility, and it can
generally be described as the ability to perform moderate to vigorous physical
activity without becoming excessively tired (Pollock et al.,
1998). |