Here are a few examples, according to Dr. Mark Hyman. He’s the director of functional medicine for the Cleveland Clinic:

Like butter… as long as it comes from grass-fed cows. It’ll be high in antioxidants - and it can actually help you burn fat by raising your metabolism. It’s down to the linoleic acid in butter from grass-fed cows - which helps our cells burn fat more efficiently and boosts the immune system.

Another food we thought was bad, but is actually good for you: Cheese. Because when we eat cheese, our gut starts churning out a fatty acid called butyrate, which helps prevent colon cancer and reduces inflammation. Cheese also lowers our risk of obesity by boosting our metabolism. The types of cheeses that produce the most butyrate are aged cheeses - like cheddar, gouda and parmesan.

And there’s grass-fed red meat. You’ll get a good dose of vitamins A, D and K. And according to the British Journal Of Nutrition, grass-fed beef is a good source of Omega-3 fatty acids. It has 50% more than regular beef.