An Integral Role of the Dietitian: Implications of the Diabetes Prevention Program

Abstract

Obesity and type 2 diabetes have become increasingly prevalent worldwide. Cross-sectional data from the Behavioral Risk Factor Surveillance System indicate that in 2000, over 56% of US adults were overweight, and during the 1990s the proportion of survey participants reporting that they had diabetes rose by 49% (1). Lifestyle changes (increasingly sedentary lifestyle and increasing dietary energy density) have resulted in a dramatic rise in obesity and type 2 diabetes in the developing economies of Latin America as well in the market economies of North America, Europe, and Australia (2). Higher fat diets and increased adiposity have also been linked to a rise in diabetes in Asia, where much of the population develops type 2 diabetes at a lower relative body weight than in Western population groups (2). The worldwide population with diabetes in expected to more than double from an estimated 135 million people in 1995 to 300 million by 2025 (2). Intermediate blood glucose levels between normal and diabetic are associated with insulin resistance and greater risk of macrovascular disease. Impaired glucose tolerance and impaired fasting glucose can be used to classify intermediate glucose values (3). The American Diabetes Association added impaired fasting glucose (defined as a fasting glucose of ≥ 6.1 mmol/L and < 7.0 mmol/L) as a classification in 1997 to more readily identity people with intermediate glucose levels in clinical settings. Studies conducted in Da Qing, China, and in Finland provided early evidence that lifestyle intervention can reduce the risk of developing diabetes in individuals with impaired glucose tolerance. The Da Qing Impaired Glucose Tolerance and Diabetes Study (n = 577) found that diet, exercise, and the combination of diet and exercise appeared to reduce the risk of developing diabetes in people with impaired glucose tolerance (4). The Finish Diabetes Prevention Study (n =523) demonstrated that a lifestyle intervention could reduce the risk of developing diabetes by 58% in individuals with impaired glucose tolerance over a 3.2-year follow-up (5). The Diabetes Prevention Program (DPP) was a large (n = 3, 234), 27-center rendomized clinical trial to evaluate the safety and efficacy of interventions in delaying or preventing diabetes in diverse populations of high-risk individuals in the United States (6).