Drudgery reduction, physical activity and energy requirements in rural livelihoods.

Low and middle-income countries in Asia and Africa have been witnessing a process of rural transformation, characterised by rising agricultural productivity, commercialisation of agriculture, improved infrastructure and access to services, over several decades. However, there is little empirical evidence on how this transformation process has affected the patterns and intensity of physical activity and time use in rural livelihoods. The lack of empirical evidence can be attributed to the constraints in accurate measurement of physical activity and energy expenditure in the context of free-living populations. Using wearable accelerometry devices, we develop robust energy expenditure profiles for men and women in rural households for two case studies in India and Ghana. An innovative feature of this study is the integration of data on energy expenditure (derived from accelerometers) with data on time-use, which has hitherto not been feasible in observational studies of rural populations. Using the data on physical activity, energy expenditure and time use from the case studies, we examine the impact of drudgery reduction- the substitution of less intense for more intense activities - on energy requirements for men and women in rural households. Our results show that drudgery reduction can have large effects on human energy (calorie) requirements, with an hour of drudgery reduction reducing energy requirements by 11-22 % for men and 13-17 % for women in Ghana and India. There are significant gender differences in energy expenditure patterns and drudgery reduction effects vary by socio-demographic characteristics and endowments of households. Our results suggest that drudgery reduction can offer rural households an important route to improved nutritional status. At the same time, drudgery reduction can lead to increased incidence of overweight and obesity for some segments of the population. The design of development interventions needs to explicitly consider the effects on nutrition and well-being through the energy expenditure dimension.