“Eat right and exercise.”

It’s good advice. But millions of us Americans struggle every day to live up to our hopes regarding diet and activity. Some of us are pretty good at one thing (for me, it’s exercise) but not good at the other (starch and sweets make up too much of my diet). It just ain’t easy to both eat right and exercise, and do so every day.

But maybe we have been making some progress on our personal goals regarding diet and activity. It looks like our collective efforts to address obesity — and associated diseases like diabetes — may be starting to have some results.

A new study from the Centers for Disease Control and Prevention recently was published in the Journal of the American Medical Association. Although the devil is in the details, the publication argues that if you look at Americans as a group, obesity and diabetes are no longer increasing as they had been in recent decades. As the Los Angeles Times reported recently, the rate at which Americans are being newly diagnosed with diabetes has now actually fallen. The statistic reflects how many new cases doctors found per thousand people. In 1990, for Americans between 20-79 years old, the number of new diabetes cases was 3.2. That figure shot up to 8.8 in 2008. The good news is that for 2012, the figure was 7.1, a downward trend worth celebrating.

But three groups are not participating in that improvement. They are Latinos, African Americans and people with only a high school education or less. For a variety of reasons, people in those groups still are experiencing a rising rate of diabetes.

“It’s not good news for everybody,” Shakira Suglia told the Los Angeles Times. Suglia is an epidemiologist at Columbia University’s Mailman School of Public Health.

And that bad news really matters because diabetes is such a debilitating disease. People with diabetes are more likely than the general population to suffer heart attacks and strokes. Beyond that there’s blindness and kidney failure to fear and problems in feet and legs that, in the worst case, can lead to amputation.

The overall problem posed by diabetes in the U.S. remains enormous. Nearly 1 in 10 Americans have the disease. There is the human dimension of the suffering that diabetes brings to people and there also is the financial cost associated with treating the disease. Our national health care bill is significantly impacted by the cost of diabetes, which was estimated at $245 billion in 2012.

Even if it’s fragmentary, let’s be thankful for at least a bit of good news in the fight against obesity and diabetes. Let’s keep up the good work and encourage one another to eat right and exercise. Everyone needs to get on board this wagon and that includes me.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard.