As U.S. President Barack Obama is inaugurated for a second term, his wife Michelle will be at his side. But the First Lady has been a significant force in her own right, tackling a major public health threat -- obesity. It is a growing problem globally, raising rates of heart disease, cancer and diabetes; nowhere more so than in the United States. Health advocates say Mrs. Obama’s high-profile campaign against childhood obesity has helped bring much-needed attention to the issue. VOA's Steve Baragona reports.