The global diversity of eating patterns: Human nutritional health in comparative perspective William R. Leonard ⁎ Department of Anthropology, Northwestern University, 1810 Hinman Avenue, Evanston, IL 60208, United States HIGHLIGHTS • Examines the origins of human nutritional needs and the diversity of human dietary strategies • Humans evolved distinct nutritional needs tied to the high metabolic costs of our large brains. • Humans have higher quality diets and greater energy expenditure than other primates of our size. • Modern human populations display a wide diversity of dietary patterns. • High energy consumption alone cannot explain the origins of obesity in modern urban societies. abstract article info Article history: Received 19 December 2013 Received in revised form 24 February 2014 Accepted 26 February 2014 Available online 5 March 2014 Keywords: Evolution Energy expenditure Diet quality Macronutrients Obesity Metabolic diseases This paper draws on comparative data to explore the evolutionary origins of human nutritional needs and the diverse strategies used by human populations to meet those needs. Humans have evolved distinctive nutritional characteristics associated with the high metabolic costs of our large brains. The evolution of larger hominid brain size necessitated the development of foraging strategies that both provided high quality foods, and required larger ranges and higher levels of energy expenditure. Over time, human subsistence strategies have become ever more efficient in obtaining energy with minimal time and effort. Compared to data from traditional, subsistence-level societies, the US diet differs markedly in its fat and carbohydrate composition, but not in its absolute energy content. Energy expenditure levels of subsistence populations are significantly higher than those of the US and other industrialized societies. These data suggest that rising rates of obesity associated with lifestyle ‘modernization’ is not simply the product of greater energy intakes, but rather shifts energy balance and diet composition. © 2014 Elsevier Inc. All rights reserved. 1. Introduction Over the last thirty years, we have witnessed dramatic changes in lifestyle and food consumption in human populations around the world [1,2]. Indeed, in many parts of the rural developing world, we are now seeing the emergence of obesity and chronic metabolic diseases in populations where such problems were unknown a generation ago. We are also seeing the development of the “dual nutritional burden” in these groups — with conditions of both overnutrition and under- nutrition co-existing in the same community, and sometimes within the same households [3]. Over the same time, scholars in a number of fields – including nutritional science, anthropology and exercise science – are recognizing the power of comparative and evolutionary approaches for studying human health and nutrition [4–8]. We have come to understand that many of the key features that distinguish humans from other primates (e.g., our bipedal form of locomotion, and large brain sizes) have impor- tant implications for our distinctive nutritional needs [8–11]. In addi- tion, we are coming to realize that an evolutionary perspective is useful for understanding the origins of and potential solutions to the growing problems of obesity and associated metabolic disorders [12–14]. The story of human evolution is a nutritional story, and one that is all about the themes of this special issue: eating and foraging patterns, diet quality and energy balance. A hallmark of human evolution has been our ability to increase the efficiency with which we extract food from our environments. Humans show tremendous diversity in their dietary regimes; in reality, what makes us human is our ability to find meal in virtually any environment. Throughout most of our past, human lifestyles were characterized by high levels of physical activity and frequent periods of marginal or negative energy balance. These condi- tions selected for improvements in the energetic efficiency of human foraging strategies. Today, we are in many respects victims of our own Physiology & Behavior 134 (2014) 5–14 ⁎ Tel.: +1 847 491 4839; fax: +1 847 467 1778. E-mail address: w-leonard1@northwestern.edu. http://dx.doi.org/10.1016/j.physbeh.2014.02.050 0031-9384/© 2014 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect Physiology & Behavior journal homepage: www.elsevier.com/locate/phb