Suzanne de La Monte, MD, a neuropathologist at Brown University whose team coined the term type 3 diabetes says that, according to her research, consuming too much sugar can lead to insulin resistance in the brain—a very bad thing. “We found that by making the brains of rats insulin resistant, the rats developed an Alzheimer-like disease pattern, including neurodegeneration,” she says. More from Prevention: 12 Ways To Never Get Diabetes A biology refresher: Our cells need glucose from food for energy. Insulin, a hormone produced in the pancreas, helps cells take in glucose from the bloodstream, which the cells then metabolize for energy. If there’s an excess of glucose in the bloodstream—from, say, your Dunkin Donuts habit—your pancreas will produce more insulin to keep up. Your cells, however, can become resistant to the increased insulin, which means that they won’t get enough energy and start to deteriorate. Starved brain cells can result in memory loss and confusion—the hallmarks of Alzheimer’s. “This problem is all about prevention,” Dr. de la Monte says. “The public health answer is to stop obesity at the youngest possible age by impressing upon parents the need to not over-feed children or feed them fast or processed foods.”But it’s not too late for adults to safeguard their health. Dr. De La Monte recommends the following:1. Keep tabs on your weight. “It takes years to reach disease levels of obesity,” Dr. de la Monte says. If you regularly weigh yourself and measure your waist, you’ll know when you’re gaining weight and you can act earlier to lose it.2. Eat less meat. Dr. De la Monte suggests moving toward plant-based foods and cutting down on meat, like the US government’s MyPlate guidelines suggest. That means half of your plate should be fruits and vegetables; the other half grains and protein. (Will giving up meat make you cranky? Check it out.)3. Cut back on sugar. Sugar is implicated in type 2 and 3 diabetes, so it’s best to keep sugar consumption to a minimum. But don’t think that reducing your sugar intake gives you license to overeat other unhealthy foods instead. “The false impression that cutting sugar in one aspect of the meal frees you up to eat four slices of pizza is completely wrong,” she says. See 5 Rules of Diabetic Eating.)4. Cook more. Learning to cook (with fresh, non-processed foods) is a good idea—and it also saves money. (Need some ideas? Our Recipe Finder has tons of quick and healthy meal ideas.)5. Avoid nitrates. Research suggests that there is a link between Alzheimer’s and consuming foods containing nitrosamines. Protect yourself by avoiding foods that list sodium nitrite on label, de la Monte writes on doctoroz.com. Common culprits are processed foods including cheese, hot dogs, ground beef, and smoked meats like bacon.