“Almost 40 percent of my 4- and 5-year-olds are obese,” said Stephen P. Bolduc, M.D., who’s been practicing pediatrics for 32 years, “and they’re not responding to traditional treatment. When I suggest they exercise more and eat less they don’t lose weight, as an overweight kid, say 10 years ago, would,” he added. He’s seeing a major shift in his practice.