Energy Requirements & Physical Activity Levels of Older People in Cuba

By Manuel Hernández-Triana, Md, PhD and Carmen Porrata-Maury, PhD

Since the decade of the 1980s it was foreseen that by the year 2001, about 60% of the human population aged 65 years and older would be from the developing world. This indicated a 78% net increase in the group 65 years and above in developing countries in the period 1980 to 2000. In 1998 in Cuba 13% of the population were aged 60 years and over; 22.8% were older than 50 years. A complete restructuring of the Cuban health care system and commitment to disease prevention and health promotion have resulted in impressive gains over the past forty years. Cuba now leads the developing countries in some categories of the infant health picture and is ranked twenty-fifth in the world overall, frequently called "a third world nation with first world health care and statistics". The reduced mortality and fertility of the Cuban population and a remarkable change in the age structure is coincident with an advanced stage of the epidemiological transition, where chronic diseases appear simultaneously with deficiency diseases. These changes are often accompanied by a sedentary lifestyle and a reduction of the total energy expenditure (TEE), which could promote weight gain.

The sudden break-up of the Eastern European bloc resulted in grave consequences for Cuba's external economic relations, resulting in a serious nutritional crisis for the population. The US blockade against Cuba has been in place for almost 40 years, and during the 1990s the sanctions against trade with the island have become tighter and more wide-reaching. In only two years the per capita intake of energy and protein of the Cuban population dropped 31% and 38% respectively. By 1993 the average Cuban diet was composed of 10% protein, 13% fat, and 77% carbohydrates as percent of total energy. According to the Cuban Report to the World Food Summit held in Rome in November 1996, after reductions of more than 30% of the Gross Domestic Product (GDP) since 1989, with a dangerous imbalance of internal finances in which the budget deficit hit 33.5% of the GDP, a slow recuperation of the Cuban economy has begun in the last three years. All the targets of the children's immunization program for the year 2000 had already been met by 1996, and the infant mortality dropped to 7.1/1000 live births by 1998. The special health and care programs for older people, however, require carefully monitoring. After the economic changes in Cuba during the early 1990s, the basic food basket consumed by the population could not meet the established requirements, especially for older people, although a slight improvement has been observed since 1993. Some studies show that the appearance of chronic energy deficiency in older Cubans is a consequence of the nutritional crisis (Table 1).

Table 1. Nutritional status according to BMI of older people in Institutions for elders in Matanzas, Cuba, 1996.

Nutritional status	BMI (weight/height2)	BMI (weight/height2)		BMI (weight/semi arm span2)
		n	%	n	%
CED Grade III	<16	15	7.1	52	24.8
CED Grade II	16-16.9	26	12.3	31	14.8
CED Grade I	17-18.4	27	12.7	27	12.9
S (Grade I-III)	<18.5	68	32.1	110	52.5
NORMAL	18.5-24.4	108	50.9	84	40
Overweight	25-29.9	28	13.2	14	6.7
Obesity	>30	8	3.8	2	1.0
TOTAL		212	100	210	100

CED: Chronic Energy Deficiency.

The physical activity of elders in rural areas is usually higher than those living in urban areas. The energy cost of the normal daily activities increases with age.^3,4 This reduced efficiency may be one of the reasons older individuals slow down, and which may also contribute to negative energy balance, weight loss and some degree of undenutrition. Coronary heart disease (CHD), obesity and non insulin dependent diabetes mellitus (NIDDM) - chronic diseases related to the ageing process and modifications of the lifestyle - are becoming a significant problem in Cuba. Modifications of the Cuban diet occurred in the 1990s relative to macro and micronutrients, and are directly related to the etiology of some of the most relevant chronic diseases in the health picture of the country.

Cuba is classified as a country with a food deficit. In 1992, the US Government ignored the warning of the American Public Health Association that the tightening of the embargo would lead to an abrupt cessation of supplies of food and medicine to Cuba, resulting in widespread "famines". Five months after the passage of the Torricelli Act the worst epidemic of neurological disease to occur during this century became widespread in Cuba. More than 50,000 of the 11 million inhabitants were suffering from optic neuropathy, deafness, loss of sensation and pain in the extremities, and a spinal disorder that impaired walking and bladder control. The Institute of Nutrition in Havana reported the association of this epidemic with the reduction in the food consumption.⁵ By 1993 food consumption had decreased by 30% when compared to 1989 levels. Food availability became critical, far below the nutritional requirements of the basic food basket, despite the fact that imports of food products and materials for processing doubled, accounting for almost 25% of the total of the country's imports.

Antioxidants and vitamin B complex are being actively investigated in relation to cardiovascular risk factors by many groups. An adequate supply of vitamins A, C and D are also directly or indirectly related with lifestyle modification and the genesis of chronic diseases. Metabolic cardiovascular syndrome and the potential risk of glucose intolerance or eventual diabetes is associated with an increased risk of clotting, hyperlipidaemias, hypertension, accelerated degenerative changes in the vasculature, small stature, abdominal obesity, and enhanced predisposition to cerebrovascular or cardiovascular incidents, and must be taken into account in formulating nutritional requirements of older persons. The diminished calcium and vitamin D intake in the diets of Cuban elders could be an important contributing factor to mortality rates. Those factors should also be taken into account in studies on the energy expenditure and energy requirements of older adults. The scientific data on energy requirements in elders is variable. This inconsistency is often generated by the data of energy intake and requirements, but more importantly by the diversity of the physical activity patterns in the aged population.

The changes in basal metabolic rate (BMR) and physical activity are the most important components of TEE. BMR reflects the energy requirements for maintenance of the intracellular environment and the mechanical processes of respiration and cardiovascular function. This generally accounts for 60-75% of the TEE. The predictive equations suggested in the report of the FAO/WHO/UNU Expert Consultation⁶ are not appropriate for calculating BMR in older persons. BMR is generally 10-20% less in older people because of reduced muscle mass and increased fat mass with ageing.

WHO, the US National Research Council, and the Department of Health of the United Kingdom have used a factorial method to estimate energy requirements, but this method underestimates energy requirements due to the difficulty of classification and quantification of physical activity. A recent evaluation of doubly labelled water (DLW) studies in adults 60 years of age and older from developed countries has shown a physical activity level (PAL) value of 1.61 for men and 1.63 for women; these results show that the energy requirements of older persons are underestimated by the above-mentioned organizations. An analysis of 574 measurements of TEE with the DLW method in older people of affluent societies has shown a PAL value of 1.62 for women from 65-74 years of age and a reduction to 1.48 for women older than 75 years. The values for men were 1.61 and 1.54. This analysis included persons with differing levels of physical activity.⁷

Table 2. Dietary energy allowances for Cuban women 60-70 years of age.

	kJoules/day Mean ± SD	kcal/day Mean ± SD	Interval
Cuban Daily Energy Allowance* (BMR × 1.60) (MJ/d)	7.67 ± 0.64 (a)	1 833 ± 152	1 632 - 2 045
BMR(a)**	4.79 ± 0.4	1 145 ± 96	1 022 - 1 278
Energy Intake (MJ/d)	5.63 ± 1.76 (b)	1 346 ± 421	729 - 2 115
Daily Energy Allowance FAO/WHO/UNU 1985 (BMR × 1,51)	7.24 ±0.60 (a)	1 730 ± 143	1 542 - 1 929
TEE by the DLW-method	7.57 ± 1.43 (a)	1 809 ± 342	1 405 - 2 511
PAL Value (TEE/BMR)	1.59		1.24 - 2.26

(Means with different superscripts are significantly different a = 0.05) (n = 11)

* Recommended Dietary Allowances for the Cuban Population.
** BMR (MJ/d)=0.038 (kg body weight) +2,755

Source: Bayley, H, Hernandez M, Estrada G., Porrata C, Monterrey P Energy expenditure by the doubly labelled water method in non-institutionalized Cuban women of 60-70 years of age from Havana City. (1999).

With the support of the International Atomic Energy Agency (IAEA) a Research Coordinated project will be carried out in a group of older adults living in a rural mountain community in western Cuba. They will participate in a medical, epidemiological, dietary and biochemical study of their nutritional status. Approximately 50 elders from the mountain community of "Las Terrazas" will be selected for the study. The population of that community differs slightly from the average Cuban older person in that: (1) They are classified as rural inhabitants but they live in a concentrated area where modern urban facilities are available. (2) They were previously employed in activities related to ecological tourism and reforestation projects, therefore their PAL and exposure to sunlight is generally higher than that of the older urban population. (3) Their intake of oily fish and other sources of vitamin D is somewhat limited. After a classification according to the absence of the metabolic cardiovascular syndrome, they will be submitted to heart rate monitoring, BMR and TEE measurement by the DLW method. The data will be used to calculate energy requirements. Inferences will be made about the relation between Syndrome X and the level of physical activity, nutritional status (especially with respect to vitamins), and appropriate light exposure.

Research on nutrition and health in old age has, thus far, received low priority, in spite of the fact that increasing longevity now establishes the need for more attention to these issues. In community health programmes, health workers will need to be equipped to advise and educate the population on healthy eating and related physical education. Adequate instruments to assess food-health relationships should be validated. Previous work at the Institute of Nutrition in Havana, in collaboration with McGill University, validated the Recommended Dietary Allowances for energy in old age. Our studies with active older people will contribute to developing the skills of future health professionals so that we can offer innovative and improved programmes for our ageing population.

References

1.	Singh J, Prentice AM, Coward WA, Ashford J, Sawyer M, Whitehead RG (1989) Energy expenditure of Gambian women during peak agricultural activity measured by doubly-labelled water method. British Journal of Nutrition 62:315-329.
2.	Tremblay A (1998) Physical activity and metabolic cardiovascular syndrome. Invited commentary. British Journal of Nutrition 80:215-216.
3.	Dumin JVGA (1985) Energy intake, energy expenditure and body composition in the elderly In Nutrition, Immunity and Illness in the Elderly Chandra RK ed. Pergamon Press, New York p 19-33.
4.	Bassey EJ, Harries UJ (1993) Normal values for handgrip strength in 920 men and women aged over 65 years, and longitudinal changes over f4 years in 620 survivors Clinical Sciences 84:331 -337.
5.	Gay J, Porrata C, Hernández M, Clua AM, Arguelles JM, Cabrera A, Silva LC (1995) Dietary factors in epidemic neuropathy on the Isle of Youth, Cuba. Bulletin of the Pan American Health Organization 29:25-36.
6.	WHO (1985) energy and protein requirements. Report of a Joint FAO/WHO/UNU Expert Consultation. Technical report Series-724, Geneva.
7.	Black AE, Coward WA, Cole TJ, Prentice A (1996) A Human Energy Expenditure in affluent societies: an analysis of 574 double-labelled water measurements. European Journal of Clinical Nutrition 50:72-92.
8.	Bayley H, Hernandez M, Estrada G, Porrata C, Monterrey P (1999) Energy expenditure by the doubly labelled water method in free-living Cuban women of 60-70 years of age from Havana City (in preparation).
9.	Porrata C, Hernández M, Arguelles JM, Proenza M (1992) Recommended Dietary Allowances for the Cuban Population. Revista Cubana de Alimentación y Nutrición 6:132-41.

Dr Hernández-Triana is Head of the Dept of Biochemistry and Physiology (tel 537 795183; fax 537 338313; email macondo@infomed.sld.cu) and Dr Porrata-Maury is Research Director (tel 537 785919; fax 537 338313; email inha@infomed.sld.cu), Institute of Nutrition and Food Hygiene, Infanta 1158, Havana 10300 Cuba.