The Urban Dictionary defines "fat-head syndrome" a tendency to act like a blowhard.

But researchers at Louisiana State University's Inflammation and Neurodegeneration Laboratory have found that a diet high in saturated fat (more than 13 percent of calories from sat fat) can cause a lot more than a bad case of know-it-all-itis!

It affects your brain, and that leads to anxiety, memory problems and other not-so-great changes in behavior.

Working in the lab, researchers transplanted gut bacteria from mice that ate a high-sat-fat diet into thin mice that ate a low-fat diet.

Lo and behold, the thin mice developed brain inflammation and had behavior changes that were the same as those of their sat-fat-munching buddies.

What does this mean for you? There's every reason to think that even if you're not overweight, eating a diet high in saturated fat throws your gut bacteria way off balance and puts you at risk for body-wide inflammation.

That means you're in for heart and immune system problems, and brain inflammation that can affect your behavior and emotional well-being.

A moderate amount of fat is essential for your good health, but it has to be the right kind: mono- and polyunsaturated, and the odd fatty omega acids 3 and 9.

So aim for, at most, 25 percent of your daily calories from healthy fats. And make sure that of a 2,000-calorie-a-day diet, no more than 2 to 6 percent of your calories (maximum 120) come from saturated fat.

You'll be healthier and happier!