Modest lifestyle changes — increasing physical activity and losing about four to six pounds — cuts nearly in half the risk of someone progressing from prediabetes to full-blown Type 2 diabetes, according to a new study in the journal JAMA Internal Medicine. Researchers found that, among 1,028 people considered at high risk for diabetes, those who made these changes were 40 to 47 percent less likely to develop diabetes in the subsequent two years than were those who did not. About 88 million adults in the United States — 1 in 3, according to the Centers for Disease Control and Prevention — have prediabetes, which means their blood sugar levels are higher than normal but not high enough to be diagnosed as diabetes. People often do not know they have developed prediabetes because it doesn’t cause any clear symptoms. Besides being a steppingstone to diabetes, prediabetes raises a person’s risk for heart disease and stroke. Eating a healthy diet, getting to and maintaining a healthy weight, and exercising regularly are considered key to keeping diabetes at bay. To this end, the National Diabetes Prevention Program works with public and private groups across the country to help people make the lifestyle changes needed to prevent diabetes or delay the progression from prediabetes to diabetes, which 34.2 million Americans have, according to the CDC.