Does Exercise — Without Change in Diet — Lower Long-Term Risk for Diabetes?

Diet and exercise together lower risk for developing type 2 diabetes. However, does exercise alone lower risk? In this study from China, researchers evaluated the long-term effects of a 12-month aerobic exercise intervention on risk for incident diabetes (defined as fasting glucose of ≥126 mg/dL, glycosylated hemoglobin [HbA_1c] ≥6.5%, or use of antidiabetes medication) in 220 adults with central obesity and nonalcoholic fatty liver disease (mean age, 54; mean baseline weight, 71 kg; mean waist circumference, 96 cm; mean HbA_1c, 6%).

Participants were randomized to 12 months of coached and supervised vigorous exercise, moderate exercise, or no exercise (controls) and were instructed not to change their diet. After the 12-month intervention (re…