What did humans evolve to eat? Human nutritional health in comparative perspective. WR Leonard Department of Anthropology Northwestern University

Transcription

1 What did humans evolve to eat? Human nutritional health in comparative perspective WR Leonard Department of Anthropology Northwestern University

2 Financial Disclosures: WR Leonard, PhD I have nothing to disclose

3 The Rise of Evolutionary Medicine Books Journals Scientific Organizations

4 Evolutionary Perspectives on Human Nutrition Particular interest in the evolution of human nutritional requirements Nutritional implications of changes in human evolution Evolutionary perspective useful for understanding today s nutritional problems

5 What did Humans Evolve to eat? Is there a single natural human Paleodiet?

6 Diversity of Modern Human Nutritional Strategies Chuño (freeze-dried potato) production in the Peruvian Altiplano Siberian herder (Evenki) preparing reindeer meat Lowland Bolivian woman (Tsimane ) pounding rice

7 Major Trends in: Human Evolution: A Nutritional Story Eating/Foraging Patterns Diet Quality Energy Allocation & Energy Balance Increased efficiency of energy extraction Evolution of Dietary Diversity

8 Homo erectus: The Emergence of Human Nutritional Ecology Increased brain size and body size Changes in foraging behavior & diet profound influences on human nutritional needs Table from: SC Antón et al Science 345:

9 Key features of Human nutritional needs established in Homo erectus High quality Diet to support the high costs of brain metabolism High Activity & Energy Demands. Foraging regimes requiring large activity budgets.

10 Overview Energetic & Dietary Correlates of Variation in Body Size & Brain Size in living primates Diversity of Dietary & Activity Patterns in Human Societies Subsistence vs. Industrialized populations Implications for understanding modern nutritional problems

11 The Expensive Brain Metabolic Rates of Selected Tissues a) Mass specific b) Total Energy Costs Data from: MA Holliday in: Human Growth, Vol. 2 (2 nd Ed.), p 101.

12 Brain Weight vs. RMR: Primates & Non-Primate Mammals

13 Percent (%) of Body s Energy for the Brain Mammals, Primates & Humans from: WR Leonard & ML Robertson AJHB 6:77

14 Percent of Metabolism for the Brain During Growth Birth = 53% 4 yr = 66% Adult = 20% Adapted from: CW Kuzawa et al PNAS 111:13010.

15 Dietary & Energetic Correlates of Size Pygmy Marmoset (110 grams = 3.9 ounces) Gorilla (145 kg = 340 lbs ) Small Body Small volume; high quality diet Large Body Large volume; low quality diet

16 Diet Quality vs. Body Weight in Primates r = Adapted from: Leonard & Robertson (1994) AJHB 6:77.

17 Percent (%) of Dietary Energy from Fat, Protein & CHO: Human & Apes Species/Group Fat Protein CHO Humans (Homo sapiens): United States (2006) Modern foragers Chimpanzees (Pan troglodytes) Gorilla (Gorilla gorilla) from: WR Leonard et al In: JP Montmayeur & J le Coutre (eds) Fat Detection, p 5.

18 Relative Brain Size vs. Diet Quality r = 0.63 from: WR Leonard et al Ann Rev Nutr 27:311.

19 Relative Proportions of Small and Large Intestines in Humans & Apes Data from: K Milton in: Food and Evolution, p. 95.

20 Day Range Variation: Humans & Other Primates ** **P < 0.01 from: WR Leonard, ML Robertson CA 38:304.

21 PAL (TEE/BMR) Energy Expenditure in Apes vs. Humans: (Physical Activity Level = TEE/BMR ) Apes ** Humans ** Apes vs. Humans: **P < 0.01 Ape data from: H Pontzer et al PNAS 111:1434. Human data from: WR Leonard Human Biol, p. 281.

22 H. erectus at 1.8 million year ago: A Major Adaptive Shift Increase in both brain & body size Human-like body proportions Evidence for increased hunting & meat eating Early African H. erectus Rapid expansion from Africa

23 Initial Spread of Homo from Africa ~1.8 million years ago from: SC Antón et al Science 345:

24 Strategies for Promoting Diet Quality in More Recent Human Evolution Evolution of tool technologies Cooking Agriculture

25 Nutritional Adaptations in Recent Human Evolution Animal herding & Milk digestion Europe: ~7,500 years ago East Africa: ~7,000 years ago Spread of Lactase Persistence in Europe from: Y Ital et al PloS Comp Biol 5(8): e Agriculture & Enhanced Starch Digestion < 10,000 years ago Variation in Amylase Gene Copies from: J Novembre et al Nat Genet 10:1189. Arctic Expansion & Increased Energy and Fat metabolism < 20,000 years ago Elevated Metabolic Rates in Siberians from: WR Leonard et al Ann Rev Anth 34:451.

26 Novel food processing techniques in Modern Human Populations Alkali Processing of Maize (Americas) Potato dehydration techniques (Andes) Processing (detoxifying) of bitter Cassava/Manioc

27 Amazonia (Tsimane ): 17% Animal foods Arctic (Evenki): 40-50% Animal foods High Andes (Quechua) 10% Animal foods

28 BMI Variation Subsistence & Industrial Populations * * Healthy BMI = Healthy BMI = *P < 0.05, relative to each subsistence group

29 Prevalence of Obesity in US Adults: 1960 to 2014 Data from: CL Ogden et al JAMA 307:491; CL Ogden et al NCHS Data Brief no. 219.

30 Changes in Daily Energy Intake & Body Weight in US Adults: from: WR Leonard Physiol & Behav 134:10.

31 Total Energy Intake vs. Basal Metabolic Rate: Subsistence & Industrial Populations a) TEI vs. BMR b) Mean (+SE) TEI/BMR Ratios TEI = 2.0xBMR TEI = 1.5xBMR TEI = BMR

32 Percent of Dietary Energy from Animal Foods: Subsistence & Industrial Populations

33 Dietary Macronutrient Composition: Subsistence & Industrial Populations US Dietary Reference 2006 Acceptable Ranges : Protein: 10-35% Fat: 20-35% CHO: 45-65%

34 Sugar consumption in the US a) Energy (kcal/d) from added sugar in US adults; b) Historic trends in US sugar consumption: ~19% of TEI From: RB Ervin & CL Ogden (2013) NCHS Data Brief No. 122 From: SJ Guyenet & J Landon (2012) Whole Health Source.

35 Differences in Dietary Fats: Subsistence & Industrial Populations Subsistence Populations: Wild/Free-ranging animals lower fat content higher levels of mono- and polyunsaturated fats Industrialized Populations: Feedlot animals higher fat content higher levels of saturated fats

36 Measuring Energy Expenditure & Work Capacity among Subsistence-level populations

37 Physical Activity Levels (PAL) in Subsistence & Industrialized Populations ** Intense * Moderate Intense Moderate Light Light n = n = *P < 0.05 **P < 0.01

38 Increased Energy Costs of Shifting from an Industrial to Subsistence Society Activity Budget +411 kcal/day +210 kcal/day

39 Implications of adding 1 hour of Exercise to the Industrialized Society Lifestyle Matches Energy Costs of Subsistence Lifestyle a) Men b) Women Industrial + exercise = +1 hour vigorous exercise

40 Physical Activity in Subsistence Populations: Sustained, modest increases in metabolism

41 Modern Life: A Shifting Energy Balance Reduced Energy & Activity for Subsistence Increased Food Availability & Energy Density of the Diet - + INTAKE EXPENDITURE

42 Implications for Understanding the Obesity Problem Nutritional recommendations must give greater attention to physical activity Debate over how much PA is necessary for a healthy lifestyle Comparative, evolutionary approach relevant for answering this question

43 Conclusions: Evolution: offers insights into: Origins of distinct nutritional needs Modern constraints Humans did not evolve to consume a single natural Paleodiet Rather, we evolved diverse strategies for meeting our distinctive needs: High quality diet Large activity budgets and Energy Expenditure

44

45 Acknowledgments Collaborators: M Robertson, JJ Snodgrass, MV Sorensen, S Antón, CW Kuzawa, T Klimova, MH Crawford, R. Godoy, TW McDade, V Reyes-Garcia Support from: US National Science Foundation, US National Institutes of Health, National Science & Engineering Council of Canada, National Geographic Society, Northwestern University