Physical activity levels in emergency affected populations

Summary of published paper

Guidelines for planning emergency general rations stipulate that energy content should depend upon:

• The age and sex structure of the population.
• Health, nutritional and physiological status.
• Physical activity levels (PAL).
• Environmental temperature.

Accurate information is rarely available in the early stages of an emergency so that an initial planning figure, or initial reference value, of 2,100 kilocalories is used to calculate energy requirements for populations in developing countries (2,300 kilocalories energy for industrialised countries). The use of a single planning figure makes the task of calculating food requirements more straightforward at a time when decisions must be made quickly with little supporting information.

This reference value has been estimated by the World Health Organisation as the mean per capita energy requirement in emergency situations globally. The figure allows for light activity (majority of time spent sitting or standing with work limited to household tasks and desirable social activity).

The mean per capita energy requirement may be adjusted once more is known about the following:

• The age and sex structure of the population
• Health, nutritional and physiological status and
• Physical activity level (PAL).

Guidelines advocate that where the workload of adults exceeds light activity the ration should be increased by 100 kilocalories for moderate activity, 150 kilocalories for moderate/heavy activity, and by 250 kilocalories for heavy activity. Differences in workloads by gender must also be considered.

Research¹ recently conducted by a team in India may call into question the validity of assuming that household activities fall into the category of light activity. The research was undertaken due to the lack of information from India and other underdeveloped countries on the actual energy costs of women's occupational and household activities.

The study attempted to measure the energy cost of activities of women from the poor socio-economic groups in India. Women between the ages of 18-40 either working for incomes or classified as homemakers were randomly selected. Time deposition studies were conducted by a 24 hour observation of their activities on a typical day. Predominant activities were identified from the activity profiles and standardised for posture and duration. The BMR and energy cost of the activities were measured by indirect calorimetry (i.e. calculating energy consumption through measuring gas exchange). The tasks were divided into standard household, childcare, occupational and other activities. Using WHO/FAO criteria attempts were made to categorise the activities into light, moderate and heavy. It was significant that except for walking the standard activities and occupational work could be classified into the light category, (>2.2BMR) while most of the household and childcare activities, except cooking, were classified as moderate to heavy activities (2.2->2.8 BMR). Mopping was the heaviest among all the activities measured requiring around 4.25 BMR. Walking holding the child was the heaviest among the child care activities (3.18 BMR).

¹Shatrugna T, Venkataramana Y, and Begum N (2000): Energy Expenditure on household, child care and occupational activities of women from urban poor households. British Journal of Nutrition (2000) vol. 83, pp 497-503