Newer guidelines suggest starting medications earlier because patients aren’t compliant with lifestyle changes:

“We recommend starting patients on metformin immediately,” said Dr. David M. Nathan, who directs the diabetes center at Massachusetts General Hospital and is a member of the group that formulated the new guidelines. “Don’t start with lifestyle alone, even for newly diagnosed people. Most end up failing the lifestyle recommendations.”

He added: “What classically happened was that the patients would take three months and try to diet. It wouldn’t work. Then they joined a health club. It didn’t work. Then they take another three months and try some more. By the time they were on effective therapy, they had had diabetes for years and years.”