OBJECTIVE -The prevalence of type 2 diabetes, especially in developing countries, has grown over the past decades. We performed a controlled clinical study to determine whether a community-based, group-centered public health intervention addressing nutrition and exercise can ameliorate glycemic control and associated cardiovascular risk factors in type 2 diabetic patients in rural Costa Rica.RESEARCH DESIGN AND METHODS -A total of 75 adults with type 2 diabetes, mean age 59 years, were randomly assigned to the intervention group or the control group. All participants received basic diabetes education. The subjects in the intervention group participated in 11 weekly nutrition classes (90 min each session). Subjects for whom exercise was deemed safe also participated in triweekly walking groups (60 min each session). Glycosylated hemoglobin, fasting plasma glucose, total cholesterol, triglycerides, HDL and LDL cholesterol, height, weight, BMI, and blood pressure were measured at baseline and the end of the study (after 12 weeks).RESULTS -The intervention group lost 1.0 Ϯ 2.2 kg compared with a weight gain in the control group of 0.4 Ϯ 2.3 kg (P ϭ 0.028). Fasting plasma glucose decreased 19 Ϯ 55 mg/dl in the intervention group and increased 16 Ϯ 78 mg/dl in the control group (P ϭ 0.048). Glycosylated hemoglobin decreased 1.8 Ϯ 2.3% in the intervention group and 0.4 Ϯ 2.3% in the control group (P ϭ 0.028).CONCLUSIONS -Glycemic control of type 2 diabetic patients can be improved through community-based, group-centered public health interventions addressing nutrition and exercise. This pilot study provides an economically feasible model for programs that aim to improve the health status of people with type 2 diabetes. Diabetes Care 26:24 -29, 2003