People are always telling Americans they should lose weight. Yada-yada-yada. You’ll be healthier somehow. Many times those folks so full of advice could use a little Jenny Craig themselves.

But now comes an actual medical research study that ties, let’s call them plus-size waistlines to losing your mind, or some of it anyway. At least I think that’s what the study says. Wait. I got distracted measuring my waistline.

Researchers from Trinity College Dublin did a statistically significant national study of 5,200 Irish senior citizens over 60. They found that people’s waist-to-hip ratio could indicate their later cognitive function.

Sounds like a flabby hypothesis, of course, if you’re overweight. But many of us are. The CDC estimated the other year that almost 40 percent of American adults, or more than 93 million of us, are obese. Even among those in their 20s 36 percent were obese, while among those 60 and older the obesity percentage was 41.

You’ll have to figure out yourself over here how this BMI obesity business works. It’s to complicated this late in life.

Now, if you’re 59 reading this, you’re fine for a few more months. But once folks hit their sixties in the study, the more belly fat they carried the worse they got in something.

What was it? I had it right here. Oh, yes, the worse their memory grew and also their judgment. Wait, there was something else. Oh, yeh, clear thinking. That gets foggier too with plus-size waistlines.

Here’s what Conal Cunningham said. He’s the new study’s senior author and a clinical associate professor in medical gerontology at Trinity:

While we have known for some time that obesity is associated with negative health consequences, our study adds to emerging evidence suggesting that obesity and where we deposit our excess weight could influence our brain health. This has significant public health implications.

Cunningham and colleagues suspect the loss of cognitive ability is due to an increased secretion of inflammatory markers in belly fat that basically sour brain functions.

The good news, if there is such a thing for us old folks’ health, is that MCI is….Wait, you don’t know what that is? Neither do I. Oh, yeh, MCI is doctor-speak for Mild Cognitive Impairment, which seems to afflict an awful lot of people in Washington.

Most elderly people develop some form of NCD over time. That’s Normal Cognitive Decline. MCI is an intermediate stage between NCD and dementia, a serious and irreversible mental decline.

Dementia seems to be spreading at a startling rate. In 2001, about 24 million people around the world were suffering from it. By 2040, experts estimate 81 million people will be living with dementia.

So, better for now just to focus on the waistline and do the recommended two hours of exercise a week to hold back the MCI. And ease up on the Guinness.