Joy Bauer is a registered dietitian and the nutrition expert for the Today Show. She’s also the best-selling author behind several health books including Your Inner Skinny. You can visit her at JoyBauer.com, or follow Joy on Facebook and Twitter.

Few nutrition research findings have brought me more pleasure than the discovery that chocolate can actually be good for you! We now have a large body of research showing that dark chocolate can help lower blood pressure, improve blood flow, reduce clotting, and benefit overall heart health. But before you dive head-first into the nearest heart-shaped box of candy this Valentine’s Day, here’s what you need to know about choosing chocolates with the most health power.

Chocolate owes its health benefits to a category of antioxidants called flavonoids. Flavonoids and other beneficial phytochemicals are found in cocoa solids, and dark chocolate contains a higher proportion of cocoa solids than milk chocolate, making it the more heart-healthy choice. That’s because milk chocolate contains more added milk and sugar, which dilutes the cocoa content. White chocolate contains no cocoa solids, only cocoa butter, which means it’s not officially chocolate and doesn’t deliver any health-promoting flavonoids.

The simplest way to select healthful chocolate is to choose brands with a high percentage of cacao or cocoa. Dark chocolate bars typically range from 35% total cacao or cocoa content (cocoa solids and cocoa butter combined) up to 100% cocoa (pure, unsweetened chocolate with nothing added). I advise people to choose dark chocolate bars labeled at least 70% cacao or cocoa if they’re looking to cash in on chocolate’s beneficial health properties. If the package doesn’t list the percent cacao on the label, you can assume it’s not high enough to meet my recommendation. And heads up: at levels higher than 80% cacao, chocolate bars can be quite bitter because they aren’t cut with much sugar, so they may not satisfy your sweet tooth.

As with so many other indulgences, portion control is key. Because chocolate is calorie-dense, I advise people to limit their daily intake to just 1 ounce. That equates to about 150 calories, give or take. A 1-ounce portion is about the size of a credit card or standard business card if you’re talking about a thin chocolate bar, like those from Lindt or Ghirardelli. If the bar is thicker, adjust accordingly. That said, I typically make an exception to the 1-ounce rule on V-Day!

Cocoa powder is also incredibly rich in flavonoids (it’s primarily cocoa solids because much of the cocoa butter is removed to produce cocoa powder). Dutch-processed cocoa powder contains significantly lower antioxidant levels than natural, unprocessed cocoa, so I always opt for the latter when I’m making healthy versions of hot chocolate or baked goods.

For a nutrient-rich Valentine’s Day treat made with antioxidant-rich cocoa powder, try my Warm Dark Chocolate Sauce with Fresh Fruit. Your sweetheart will be in chocolate heaven!

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