Alma Schneider, who is generally in good health, was taken aback when her doctor told her she has prediabetes.

The 47-year-old in Montclair, N.J., was stymied. “Honestly, I wish I didn’t know. I mean for me, because I’m healthy, there’s not much I can do besides have the stress in my head. Every time I eat something now I’m worried.”

Some experts also say prediabetes, or blood-sugar levels that are higher than normal but not high enough to qualify as diabetes, is often best left undiagnosed. They are pushing back against a recent initiative by the U.S. Centers for Disease Control and Prevention to encourage people to get screened for the condition. Critics of the agency’s campaign say it threatens to turn millions of people, many of whom don’t have a medical problem, into patients.

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More than 1 in 3 adults in the U.S. have prediabetes, most of whom aren’t aware of it, the CDC warns. Without intervention, between 15 and 30 percent of those people will develop Type 2 diabetes within five years, the public-health agency says. Often considered an epidemic, Type 2 diabetes has been diagnosed in about 22 million people in the U.S., up from 5.5 million in 1980. The American Diabetes Association and American Medical Association are partners in the CDC’s public-awareness campaign for prediabetes.

“What is the impact of telling somebody you have prediabetes and an increased risk of diabetes?” says Robert Ratner, chief scientific and medical officer for the American Diabetes Association. “Number one, you get their attention and get them to pay attention to their lifestyle. What’s the downside of a better lifestyle?”

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