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close this bookEnergy and Protein requirements, Proceedings of an IDECG workshop, November 1994, London, UK, Supplement of the European Journal of Clinical Nutrition (International Dietary Energy Consultative Group - IDECG, 1994, 198 pages)
close this folderEnergy requirements of older individuals
View the document(introductory text...)
View the documentIntroduction
View the documentMethodology for determination of total energy expenditure
View the documentTotal energy expenditure of older individuals
View the documentRelationship between total energy expenditure and physical activity
View the documentEffects of energy balance on nitrogen balance
View the documentSummary of energy requirements in older individuals and recommendations for future research
View the documentReferences
View the documentDiscussion

Total energy expenditure of older individuals

To our knowledge, there are six studies of TEE in older individuals that have been published (Prentice et al, 1988; Goran & Poehlman, 1992; Roberts et al, 1992; Reilly et al, 1993; Sawaya et al, 1994; Pannemans & Westerterp, 1995). In these studies, a total of 38 free living men, 36 free-living women and 14 hospitalized male and female mental patients have been investigated (Table 2), and these within the younger segment of older individuals. In only three of the six studies (31 men and 20 women) were there measurements in young as well as in older subjects.

Table 3 gives a summary of relevant details of the subjects and data from the studies in older men (mean ages 64-74 years). The values for TEE are those reported by the authors, as well as 'adjusted' mean values (aTEE) which represent our effort to standardize calculation procedures between groups. As described in the legend to the table, the adjusted values all include a 2% increase in TEE to account for the expected lower rate of fractionated water loss in older individuals (Roberts et al, 1992). In addition, data of Goran & Poehlman (1992) were adjusted to take into account the fact that they used a mean measured ratio of the dilution spaces (2H2O: H2 18O) which was higher than the values used in the other studies. Although the necessity of using group-specific dilution space ratios has been considered, there is currently no available evidence to support the validity of this approach and, as noted by Goran & Poehlman (1992), it results in calculated values for TEE 10.5% lower than the use of a standard mean dilution space ratio of 1.03 (Schoeller et al, 1986).

Table 3 Published values for total energy expenditure in free-living older men measured using the doubly labeled water methoda

Authors

Goran & Poehlman (1992)d

Roberts et al (1992)

Pannemans & Westerterp (1995)c

Mean PAL

n

7

15

16


Age (y)

68 ± 6

69 ± 7

71 ± 5


Height (cm)

175 ± 9

177 ± 8

172 ± 9


Weight (kg)

77.1 ± 7.4

75.4 ± 9.7

74.0 ± 12.6


REE (kcal/d)





measured

1715 ± 183

1429 ± 157

1599


predictedb

1526 ± 100

1506 ± 130

1486


TEE (kcal/d)





measured

2675 ± 394

2495 ± 352

2412


adjustedc

3014 ± 444

2495 ± 352

2460


Mean TEE (kcal/kg)





measured

34.7

33.5

32.6


adjustedc

39.1

33.5

33.2


PAL values:





Mean TEE/mREE

1.58

1.75

1.51

1.61

Mean TEE/pREE

1.77

1.66

1.62

1.68

Mean aTEE/mREE

1.78

1.75

1.54

1.69

Mean aTEE/pREE

1.99

1.66

1.66

1.77

a Values are group means with ± s.d.. where data are available.
b Predicted values for REE determined from body weight using FAO/WHO/UNU (1985) equations.
c Adjusted values:
d for Goran & Poehlman (1992) are increased by 12.71% (10.5% for possible underestimation of TEE associated with using high ratio for the
2H: 18O dilution space, and 2% for lower rate of insensible water loss in elderly subjects as predicted by Roberts et al (1992));
e for Pannemans & Westerterp (1995) increased by 2% for lower rate of insensible water loss in elderly subjects as predicted by Roberts et al (1992). Note that the observed negative energy balance in this population is not accounted for in the adjusted TEE.

The reported and adjusted values for TEE in older men are given in Table 3, expressed as absolute values as well as ratios of mREE and pREE (FAO/WHO/ UNU, 1985). It can be seen that both the adjustment to TEE, as well as whether mREE or pREE is the chosen denominator, exert a significant influence on the PAL index in some individual studies. The ratio aTEE/pREE may represent the best estimate of energy requirements in this group. It should be noted that the aTEE/pREE ratio for the study of Goran & Poehlman (1992) differs significantly from data of the other two studies. Excluding the data of Goran & Poehlman (1992), a mean aTEE/pREE of 1.66 is obtained. This value is very slightly higher than the current recommended value of 1.51 for older individuals.

Data on the TEE of older women are given in Table 4. As with the studies in men, there is a relatively narrow range for mean age in these studies, ranging from 64 to 74 years. The reported and adjusted values for TEE are given in the table, expressed as absolute values as well as ratios of the mREE and pREE (FAO/ WHO/UNU, 1985). As seen in the data from men, both the adjustment to TEE and the use of mREE compared to pREE, exert a significant influence on the TEE/PEE ratio in some individual studies (Table 4). The mean aTEE/pREE ratio for all studies combined is 1.71, and in this case data from the study of Goran & Poehlman (1992) do not appear to lie outside the range of the other studies. The mean unadjusted TEE/pREE (1.64) is somewhat lower than the aTEE/pREE, but as with the data from men this value is higher than the current recommended value of 1.51 (FAO/WHO/UNU, 1985).

A combined summary of data from men and women is given in Table 5. Taken together, the studies on men and women provide no evidence of any influence of gender on TEE/pREE in older individuals, although it should be noted that the mean TEE/PEE ratio is indeed lower in women than in men in our own studies, which to our knowledge have involved the largest number of older subjects studied by any one group (Roberts et al, 1992; Sawaya et al, 1995). After excluding data that are influenced by the use of different doubly labeled water calculation procedures and the use of measured vs predicted values for REE, the weighted mean aTEE/pREE ratio for men and women combined is 1.66 and the mean TEE/pREE ratio is 1.64. Both of these values are higher than the current suggested value (1.51 for persons >50 years). It might be hypothesized that these values could be high because of a positive adaptation in energy expenditure to overeating during the TEE measurements. However, our recent overfeeding studies in young and older men have indicated that there is only a small increase in TEE with short term overfeeding (averaging 165 kcal/d) and this is due primarily to an increase in REE associated with increased fat and fat-free mass (Roberts et al, 1990). Thus, the ratio of TEE/PEE does not increase with overeating, and it would appear that adaptive variations in TEE due to overeating should not be of significant concern when using measurements of TEE to examine energy requirements.

Another important question concerning the energy requirements of older individuals is how TEE/PEE changes with age. Although there is little information on this issue, current recommended dietary allowances assume a modest decrease in TEE/pREE up to the age of 50 years (FAO/WHO/UNU, 1985). Our own studies in both young and older men and women (Roberts et al, 1992; Sawaya et al, 1995) support the suggestion of a modest decrease in TEE/pREE between the ages of 25 and 70 years. To quantify this change further, we performed a multiple regression analysis on our combined data set of 55 young and older men and women. The most significant predictor of TEE/pREE was percent body fat (since fat free mass is already accounted for through its close association with REE) and neither gender nor age was significant when included in models with percent fat (data not shown). Thus, the PAL index can be expected to fall with age in association with the usual increase in the proportion of body fat content.

Table 4 Published values for total energy expenditure in free-living older women measured using the doubly labeled water methoda

Authors

Goran & Poehlman (1992)d

Reilly et al (1993)e

Sawaya et al (1993)

Pannemans & Westerterp (1995)f

Mean PAL

n

6

10

10

10


Age (y)

64 ± 5

73 ± 3

74 ± 2

67.6 ± 4.1


Height (cm)

165 ± 3

-

155 ± 5

160 ± 8


Weight (kg)

65.2 ± 7.8

60.0 ± 7.2

58.5 ± 9.9

65.4 ± 5.9


REE (kcal/d)






measured

1472 ± 129

1221 ± 91

1144 ± 103

1219


predictedb

1281 ± 82

1226 ± 75

1210

1283


TEE (kcal/d)






measured

2092 ± 231

2201 ± 354

1852 ± 214

2065


adjustedc

2358 ± 261

2245 ± 354

1852 ± 214

2165


Mean TEE (kcal/kg)






measured

32.1

37.0

31.7

30.9


adjustedc

36.2

37.7

31.7

31.6


PAL values:






Mean TEE/mREE

1.43

1.80

1.62

1.66

1.63

Mean TEE/pREE

1.64

1.80

1.53

1.58

1.64

Mean aTEE/mREE

1.62

1.84

1.62

1.66

1.69

Mean aTEE/pREE

1.85

1.84

1.53

1.61

1.71

a Values are group means with ± s.d. where data are available.
b Predicted values for REE determined from body weight using FAO/WHO/UNU (1985) equations.
c Adjusted values:
d for Goran &: Poehlman (1992) are increased by 12.71% (10.5% for possible underestimation of TEE associated with using high ratio for the 2H: 18O dilution space, and 2% for lower rate of insensible water loss in elderly subjects as predicted by Roberts et al (1992));
e for Reilly et al 1993) increased by 2% for lower rate of insensible water loss in elderly subjects as predicted by Roberts et al (1992);
f for Pannemans & Westerterp (1995) increased by 2% for lower rate of insensible water loss in elderly subjects as predicted by Roberts et al (1992). Note that the observed negative energy balance in this population is not accounted for in the adjusted TEE.

Table 5 Summary of weighted means for PAL indicators in older men and women



Men & women


Men

Women

All

Selected studiesa

TEE/PEE

1.61

1.63

1.62

1.67

TEE/pREE

1.68

1.64

1.66

1.64

aTEE/REE

1.69

1.69

1.69

1.68

aTEE/pREE

1.77

1.71

1.75

1.66

a Excluding data of Goran & Poehlman (1992), which are strongly influenced by the use of data for adjusted TEE and pREE.


Figure 1
Relationship between the ratio of total to resting energy expenditure and reported, self-defined strenuous physical activity in healthy elderly men.