DULUTH — A few months ago Dr. Maria Barrell, a family practice resident in Duluth, had a patient admitted to the hospital. The woman had recently been diagnosed with diabetes. Barrell had a long talk with the patient about the negative health effects of sugar-sweetened beverages. One 12-oz can of Mountain Dew, for example, contains almost three tablespoons of sugar. They're linked to obesity and diabetes, cardiovascular problems and a heightened risk of stroke. That has spurred some in the medical community to action. In the past few months, several hospitals in northeast Minnesota have stopped selling soda and other beverages that are sweetened with sugar.