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Unformatted text preview: The Summer Meeting of the Nutrition Society, hosted by the Institute of Food Research, was held at the University of East Anglia, Norwich on 28 June1 July 2005 Opening Lecture The ancestral human diet: what was it and should it be a paradigm for contemporary nutrition? S. Boyd Eaton Departments of Anthropology and Radiology, Emory University, Atlanta, GA 30327, USA Awareness of the ancestral human diet might advance traditional nutrition science. The human genome has hardly changed since the emergence of behaviourally-modern humans in East Africa 10050 10 3 years ago; genetically, man remains adapted for the foods consumed then. The best available estimates suggest that those ancestors obtained about 35% of their dietary energy from fats, 35% from carbohydrates and 30% from protein. Saturated fats contributed approximately 7 . 5% total energy and harmful trans-fatty acids contributed negligible amounts. Polyunsaturated fat intake was high, with n-6: n-3 approaching 2:1 ( v . 10:1 today). Cholesterol consumption was substantial, perhaps 480 mg/d. Carbohydrate came from uncultivated fruits and vegetables, approximately 50% energy intake as compared with the present level of 16% energy intake for Americans. High fruit and vegetable intake and minimal grain and dairy consumption made ancestral diets base-yielding, unlike todays acid-producing pattern. Honey comprised 23% energy intake as compared with the 15% added sugars contribute currently. Fibre consumption was high, perhaps 100 g/d, but phytate content was minimal. Vitamin, mineral and (probably) phytochemical intake was typically 1 . 5 to eight times that of today except for that of Na, generally < 1000 mg/d, i.e. much less than that of K. The field of nutrition science suffers from the absence of a unifying hypothesis on which to build a dietary strategy for prevention; there is no Kuhnian paradigm, which some researchers believe to be a prerequisite for progress in any scientific discipline. An understanding of human evolutionary experience and its relevance to contemporary nutritional requirements may address this critical deficiency. Human evolution: Dietary recommendations: Ancestral human diet: Health promotion Contemporary nutritional advice is based heavily on epidemiological research findings. Grant funding, aca- demic publications, official recommendations, conferences and popular media accounts related to diet commonly reflect an underlying presupposition that the epidemio- logical method has the greatest scientific validity as well as the most potential for elucidating human nutritional requirements. The present paper suggests there is an alter- native or, better, a complementary investigative discipline that should inform the field of nutrition science. The goals would be to better organize and re-interpret previous research findings, to provide direction for future studies and, ultimately, to integrate basic science and public health pro- motion efforts into a seamless, understandable and logically-...
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- Spring '08