Wondering how to prevent dementia? Grandpa Gustafsson (played by Burgess Meredith) proved that old age doesn’t equal slow-witted in the movie “Grumpy Old Men” when he coined the 10 funniest euphemisms for lovemaking ever heard (e.g., “taking old one-eye to the optometrist”).

Unfortunately, for the 12 million or more North Americans who are age 60 or older and obese, the prospects for such an entertaining old age are, well, not so funny. One study reveals that obesity can put people older than 60 at greater risk for dementia. The good news is we have some tips that can spare your aging brain from weight-gain brain-drain:

• Take a walk for at least 45 minutes a day, six days a week. Also do strength-building exercises two to three days a week. It’s especially good for you if you’re advanced in your years and out of shape. Yes, AARP member, you can do it!

• Add friends, family, and lovers to your social mix — face to face, not using FaceTime on your cell phone. Loneliness is associated with everything from higher blood pressure and less happiness to weight gain.

• Substitute heart-stopping saturated fats (think burgers) with healthy fats, such as salmon or mono-unsaturated olive oil. Losing weight is about healthy eating, not starving.

• Combine these steps with Dr. Mike’s secret for weight control: walnuts and almonds. Starting a meal with six walnut halves or 12 almonds can help you shrink belly fat by 50%. The walnuts are good for your brain and heart, too, so go nuts (and have a fun-filled — and longer — life)!