For much of the last 25 years the focus of nutritional advice has been to reduce total fat intake and consume large amounts of carbohydrate. However, this advice was inconsistent with many lines of evidence indicating that unsaturated fats have beneficial metabolic effects and reduce risk of coronary heart disease. More recent evidence has also shown that the large majority of carbohydrates in current industrial diets, consisting of refined starches and sugar, have adverse metabolic effects and increase risks of obesity, heart disease and type 2 diabetes. Also, red meat consumption is associated with increased risks of diabetes, cardiovascular disease, some cancers, and total mortality, and replacement of red meat with nuts and legumes is strongly associated with lower risk of these outcomes. Thus, in an optimal diet, most calories would come from a balance of whole grains and plant oils, and proteins would be provided by a mix of nuts, beans, fish, eggs, and poultry. Higher intake of fruits and vegetables (not including potatoes) is associated with lower risks of cardiovascular disease, although the benefits for cancer prevention appear to be less than anticipated. A shift from the current US diet to a more optimal way of eating would have a profoundly beneficial effect on health and wellbeing of Americans.

Biography
Dr. Walter Willett is Professor of Epidemiology and Nutrition and Chairman of the Department of Nutrition at Harvard School of Public Health and Professor of Medicine at Harvard Medical School. Dr. Willett, an American, was born in Hart, Michigan and grew up in Madison, Wisconsin, studied food science at Michigan State University, and graduated from the University of Michigan Medical School before obtaining a Doctorate in Public Health from Harvard School of Public Health. Dr. Willett has focused much of his work over the last 35 years on the development of methods, using both questionnaire and biochemical approaches, to study the effects of diet on the occurrence of major diseases. He has applied these methods starting in 1980 in the Nurses’ Health Studies I and II and the Health Professionals Follow-up Study. Together, these cohorts that include nearly 300,000 men and women with repeated dietary assessments are providing the most detailed information on the long-term health consequences of food choices.

Dr. Willett has published over 1,500 articles, primarily on lifestyle risk factors for heart disease and cancer, and has written the textbook, Nutritional Epidemiology, published by Oxford University Press. He also has four books for the general public, Eat, Drink and Be Healthy: The Harvard Medical School Guide to Healthy Eating, which has appeared on most major bestseller lists, Eat, Drink, and Weigh Less, co-authored with Mollie Katzen, The Fertility Diet, co-authored with Jorge Chavarro and Pat Skerrett and most recently Thinfluence, co-authored with Malissa Wood and Dan Childs. Dr. Willett is the most cited nutritionist internationally, and is among the five most cited persons in all fields of clinical science. He is a member of the Institute of Medicine of the National Academy of Sciences and the recipient of many national and international awards for his research.