There’s a reason why the cliché “an ounce of prevention is worth a pound of cure” rings true. Health is easier to maintain than to regain. But that old adage understates just how difficult the work of prevention really is. People at risk need to be educated and motivated; most are neither.

To see one formidable challenge preventive medicine is up against, look no further than the sobering statistics in this month’s cover story on diabetic retinopathy. Drs. Steven Ferrucci and Brenda Yeh do an excellent job of laying out in black and white the debilitating impact diabetes has on millions of people today and the threat that looms over millions more. “An estimated 25.6 million Americans age 20 or older have diabetes, with a third still undiagnosed,” they write. “An additional 79 million people have prediabetes, and are at risk for developing diabetes.” 

That’s over 100 million people—a third of the population—in harm’s way. For those who already have diabetes, the prevalence of diabetic retinopathy among adults is 28.5%, or 4.2 million Americans, Drs. Ferrucci and Yeh write. “If the overall rate of diabetes continues to rise at the current trajectory, the projected prevalence of individuals with any diabetic retinopathy by 2020 will increase to six million, with 1.34 million having sight-threatening disease.”

So, those are the stakes—in ocular health alone. And of course, the threat extends far beyond the eye. Prevention is urgently needed.

Despite decades of public outreach on the importance of lifestyle change, diabetes remains deeply entrenched in America. What’s undergirding it? Girth, frankly. Americans remain overweight at unprecedented levels. 

New research in the June 7 issue of JAMA provides an update on obesity in the US. “The news is neither good nor surprising,” the authors write. “Using 2013-2014 data from 5,455 adults,” they say, “35% of men were obese (BMI≥30) and 5.5% were morbidly obese (BMI≥40); among adult women, 40.4% were obese and 9.9% were morbidly obese. These prevalences are unchanged since 2005 among men and represent a slight increase in obesity among women.” In children, obesity rates decreased among those age two to five since 2003-2004, stabilized in 6- to 11-year-olds since 2007-2008, “but steadily increased among adolescents since 1988,” the study finds. Childhood obesity has a prevalence of 17%; for extreme obesity, it’s 5.8%.

Problems this pervasive won’t get fixed any time soon. But you can help by deciding that all aspects of diabetes are appropriate for an optometrist to address. Don’t limit your role to diabetic retinopathy. Get involved earlier in its course, discussing risk factors and even, delicately, how obesity sets up patients to fail. 

Few professions perform as much routine care as optometry. A concerted effort to raise diabetes awareness and change behavior could be the profession’s biggest opportunity and greatest gift.