In Monty Python's movie "The Meaning of Life," the maitre d' of a French restaurant (John Cleese) persuades the monstrously obese patron Mr. Creosote (Terry Jones) to have just one more little after-dinner mint. When Creosote eats the mint, he explodes all over the restaurant.

True, a healthy amount of body fat has great powers: It promotes reproductive health, good skin quality, and clear thinking. Fat cells also help trigger chemical reactions that control growth, immune function, and other aspects of basic metabolism.

But too much body fat (visceral fat around your organs and fat under your skin) does more than make your jeans tight. In addition, it triggers massive inflammation and increases your risk of everything from depression to cancer.

And a new study says it sets off a cascade of signals that changes how your brain deals with stressful events and metabolism.

In short, excess body fat can interfere with your ability to turn off your stress response, putting you into cortisol-fueled, heart-damaging, immune-system-weakening, memory-decaying, food-craving overdrive.

You get sucked into a vicious cycle of overeating, feeling stressed and then overeating again to feel soothed.

The good news is that knowing this gives you a powerful way to feel more relaxed and lose weight: Get yourself on a diet that has no trans and little saturated fat; no added sugars or syrups; and no grain that isn't 100 percent whole. And start walking 10,000 steps a day.

Then your brain can start helping your body shape up and calm down.