2002 Public Health Symposium

Keynote Address: The Obesity Epidemic: Causes, Consequences and Solutions

William Dietz, MD, PhD
Director, Physical Activity and Nutrition
Centers for Disease Control

William Dietz Overweight and obesity have reached epidemic proportions in the United States. More than 45 million adults are obese, and the 10-15% of children ages 6-17 years (about 8 million young people) are considered overweight. The increase in overweight and obesity has been created by many factors. Genetic, metabolic, behavioral, environmental, cultural and socioeconomic influences all have some role in the development of the problem. For most individuals, an excess of calories consumed and/or inadequate calories expended in physical activity are major causal factors in developing overweight and obesity. The current environment provides opportunities for food consumption in many different settings. The same environment decreases the availability and need for physical activity in the work place and many other settings, such as schools. This environment encourages calorie consumption without the increasing calorie expenditure that would prevent weight gain.

The consequences of the obesity epidemic are being seen in several different areas. Overweight and obesity are associated with increased risks for chronic disease, including coronary heart disease, type 2 diabetes, several types of cancers and some musculoskeletal disorders, such as osteoarthritis. Increased health risks are being seen in children as well as adults. The health care to deal with the obesity epidemic will have direct costs (preventive, diagnostic and treatment services) and indirect costs (wages lost due to illness or disability). Treatment for overweight or obesity has been quite ineffective, making it necessary to identify additional predisposing factors and barriers to weight loss and maintenance, both for children and adults. Effective strategies for preventing or treating overweight, obesity, and the resultant chronic diseases must include consideration of environmental and policy issues such as the types of food available in a wide variety of eating places (are lower calorie/higher nutrient choices such as fruits and vegetables available?) and the facilities available for physical activity (are sidewalks laid out in new residential developments and around new schools?). Solutions for the obesity epidemic must include efforts that reach from national program levels to individuals in communities. There is a need for greater emphasis on working across nutrition and physical activity programs, all the way from the federal to the state and local levels. Knowledge of common activities can help in determining the effectiveness of a wide variety of intervention strategies. It is also important to include the medical community in the resolution of the obesity epidemic. There is a new emphasis on primary medical care providers inquiring about dietary intake and physical activity in their patient treatment. The obesity epidemic has also resulted in some new partnerships, including the use of public lands for a variety of outdoor physical activities. The solutions to the current epidemic depend on using our understanding of the scientific bases for the problems and partnering that understanding with outreach to communities and individuals in a way that takes advantage of our educational and programmatic resources, and recognizes our cultural diversity.

Dr. Dietz is the Director of the Division of Nutrition and Physical Activity in the Center for Chronic Disease Prevention and Health Promotion at the CDC. Prior to his appointment to the CDC, he was a Professor of Pediatrics at the Tufts University School of Medicine, and Director of Clinical Nutrition at the Floating Hospital of New England Medical Center Hospitals. He received his BA from Wesleyan University in 1966 and his MD from the University of Pennsylvania in 1970. Following an internship at Children's Hospital of Philadelphia, he spent 3 years in the Middle America Research Unit of the National Institute of Allergy and Infectious Disease in Panama, studying insect borne viruses. After the completion of his residency at Upstate Medical Center, he received a PhD in Nutritional Biochemistry from Massachusetts Institute of Technology.

In addition to his academic responsibilities in Boston, Dr. Dietz was a principal research scientist at the MIT/Harvard Division of Health Science and Technology, Associate Director of the Clinical Research Center at the Massachusetts Institute of Technology, and Director of the Boston Obesity/Nutrition Research Center funded by NIDDK. He has been a councilor and past president of the American Society for Clinical Nutrition, and past president of the North American Association for the Study of Obesity. In 1995 he received the John Stalker award from the American School Food Service Association for his efforts to improve the school lunch. Dr. Dietz served on the 1995 Dietary Guidelines Advisory Committee. He was a member of the NIDDK Task Force on Obesity. In 1997, Dr. Dietz received the Brock Medal of Excellence in Pediatrics from the New York Academy of Medicine. In 1998, Dr. Dietz was elected to the Institute of Medicine of the National Academy of Sciences. In 2000, he received the William G. Anderson Award from the American Alliance for Health, Physical Education, Recreation and Dance, and was recognized for excellence in his work and advocacy by the Association of State and Territorial Public Health Nutrition Directors. In 2002, Dr. Dietz received the Holroyd-Sherry award from the American Academy of Pediatrics for his research and advocacy on the effects of television on children. Also In 2002, he was elected as an honorary member of the American Dietetic Association. He is the author of over 150 publications in the scientific literature, and the editor of two books, including A Guide to Your Child's Nutrition.