On hearing diagnosis diabetes, it’s tempting to succumb to believing half-truths or to rely on hearsay from friends who “know someone with the disease” as you cope with the news. The only surefire way to boost your health, though, is to deal in whole-truths. Understanding your condition is crucial to living the best you can with it. Here, Professor Ronald Goldberg, MD, from the Division of Endocrinology, Diabetes and Metabolism at University of Miami’s Miller School of Medicine, reveals, and dismisses, outlandish diabetes myths he’s heard over his 35-year career. He’s not letting anyone off the hook—quality-of-life is on the line!

MYTH 1: I may have developed diabetes, but I don’t overeat.

Being overweight leads to some 30 percent of Type-2-diabetes cases, says Goldberg, adding, “We often shroud ourselves with ignorance about how much we eat.” Yet, with ginormous portion sizes, junk food’s in-our-face availability, and rampant over-the-top snacking, over-indulging is easy. “Our patients’ first stop is the dietician. Many are awestruck to learn they overeat.” Find your suggested caloric intake with this American Heart Association tool. “Know your calorie limit,” says Goldberg, “so you can stay within it.”

MYTH 2: I have just a touch of diabetes, a borderline case not requiring change.

Big mistake. Don’t let diabetes’ early asymptomatic stages fool you. Whether it’s prediabetes or diabetes, says Goldberg, your body’s tissues are already being damaged. Frame this accurately: As a call to make drastic changes. Schedule regular checkups, up exercise, and work with your doctor to stop smoking, reduce blood sugar, weight, blood pressure, and/or cholesterol. Under the old paradigm, diabetes diagnoses often occurred at late stages, when heinous complications hospitalized people. Still today, the average person diagnosed with Type 2 diabetes has had the disease some seven years. Consider yourself lucky if you’re diagnosed earlier. Zap it with lifestyle changes and, when needed,  medications as doctor-directed.

MYTH 3: My doctor prescribed insulin, which feels like a death sentence.

Snap out of it. It’s nothing of the sort. Among people who develop diabetes, about half will end up taking insulin, says Goldberg, though it takes about 10 years for the average person with the disease to reach this point. Decades ago, taking insulin was complicated, involving boiling syringes. Today, needles are fine and short. Often, just one injection daily is required. Rejecting this treatment, says Goldberg, isn’t wise.