Original Research Article Energy Expenditure Among Farmers in Developing Countries: What Do We Know? DARNA L. DUFOUR 1 * AND BARBARA A. PIPERATA 2 1 Department of Anthropology, University of Colorado, Boulder, Colorado 80309 2 Department of Anthropology, Ohio State University, Columbus, Ohio 43210 ABSTRACT The trend toward overweight and obesity in developing countries is often assumed to be due, in part, to reductions in energy expenditure associated with the transition from agrarian to urban lifestyles. In this article we first review the published studies on energy expenditure in farming populations living in developing countries, populations gen- erally assumed to have high levels of energy expenditure. To facilitate comparison we express energy expenditure as physi- cal activity level (PAL), i.e. the ratio of total daily energy expenditure to basal metabolic rate. Then, with the goal of better understanding variability in energy expenditure between different human groups, we focus on case studies of women farm- ers in Colombia and Brazil for whom we have good ethnographic data. The published studies reviewed indicate that most farmers have PAL values in the moderate physical activity range, but toward the high end of that range. PAL values of male farmers tend to be higher than female, and show greater seasonal variation. The case studies illustrate that women farmers, living in broadly similar environments, and dependent on the cultivation of the same crop can have quite different patterns of physical activity and hence PAL values. These differences are a function of differences in behavior related to social and cultural variables like the organization of work at the household level and perceptions of how food crops should be processed, as well as micro-level ecological factors. Am. J. Hum. Biol. 20:249–258, 2008. ' 2008 Wiley-Liss, Inc. The global trend toward increased overweight and obe- sity has led to a renewed interest in physical activity and energy expenditure. The trend toward overweight and obesity is as much of a problem in developing countries as elsewhere and indeed the prevalence of both has risen dramatically in many developing countries over the past 20–30 years (WHO, 1998). We know that overweight and obesity are the consequence of long-term imbalances between food energy intake and energy expenditure in individuals, i.e. when energy intake exceeds expenditure the surplus energy accumulates as tissue (mostly fat) and body weight increases. What we still do not under- stand very well are the factors responsible for intake exceeding expenditure for so many people in so many dif- ferent places. The dominant explanatory model for this increased prevalence of overweight and obesity is that of the nutri- tion transition which posits that these changes are the result of large scale shifts toward a western-style diet high in fats, sugars, and refined foods, and a lifestyle char- acterized by low levels of physical activity (Popkin and Gordon-Larsen, 2004). The shifts in diet have been better documented than the changes in physical activity, which remain a major gap in our knowledge (Monteiro et al., 1995; Popkin, 2006). The greater focus on diet is likely due to the fact that the current discussion is based upon the analysis of national data sets, which often include national food supply and disappearance data making shifts in dietary patterns, at least on the large scale, visi- ble. National level data on physical activity are not gener- ally available. Although such an assumption appears to be widely accepted, the fact that there are little data to support it is often overlooked. Studies of physical activity and energy expenditure in farming populations are limited in num- ber. There are no long-term studies of the changes in energy expenditure that are assumed to accompany migration from a rural agrarian lifestyle to an urban serv- ice sector one, and the few studies comparing energy ex- penditure in rural agrarian communities to urban ones have produced conflicting results. For example, Borgonha et al. (2000) reported significantly lower levels of energy expenditure in male workers living in economically depressed urban areas of India in comparison to male ag- ricultural workers. In contrast, Yamauchi et al. (2001) found similar levels of energy expenditure among male town dwellers and subsistence agriculturalists in Papua New Guinea (PNG), and noted that although the energy cost of the work done by the town dwellers was lower than that of agricultural work, the lower cost was offset by the longer working hours. The purpose of this article is first to review the available literature on energy expenditure in farming populations living in developing countries with the goal of determining the level(s) of energy expenditure associated with that lifestyle. In other words, how energetically demanding is the farming lifestyle? While often assumed to be high, we expect energy expenditure to be variable both within farming populations seasonally and between the sexes, and between populations, based on staple crops, local eco- logical conditions, and degree of market integration. For example, populations reliant on highly seasonal crops may experience periods of high energy expenditure during planting and/or harvest, followed by periods of signifi- Contract grant sponsor: National Science Foundation; Contract grant numbers: BSN 75-20169, BCS 0201936; Contract grant sponsor: Wenner Gren Foundation for Anthropological Research Inc., Brazil; Contract grant number: 6861; Contract grant sponsor: Social Science Research Council, Colombia. *Correspondence to: Darna L. Dufour, Department of Anthropology, Uni- versity of Colorado, Boulder, CO 80309-0233, USA. E-mail: darna.dufour@colorado.edu Received 24 August 2007; Accepted 28 December 2007 DOI 10.1002/ajhb.20764 Published online 17 March 2008 in Wiley InterScience (www.interscience. wiley.com). AMERICAN JOURNAL OF HUMAN BIOLOGY 20:249–258 (2008) V V C 2008 Wiley-Liss, Inc.