If you’re keen to get the most flavanols from your chocolate fix, you might have to do some hunting, since most manufacturers don’t list flavanol content on their product labels. But since the compounds are found only in the cocoa component of chocolate, seeking out cocoa, or chocolate with a higher cocoa content, should theoretically send more flavanols your way. So can choosing dark rather than milk chocolate, which, because of the added milk, contains a lower percentage of cocoa solids. Opt for natural cocoa over dutched cocoa powder as well, since a substantial amount of flavanols are lost when cocoa is alkalized. Of course, all those steps are no guarantee of high flavanols, since manufacturing processes like roasting and fermenting cocoa beans can have a huge effect on flavanol content, too—and those vary widely from brand to brand. Your best bet is to contact the manufacturer and ask.
But of course, any positive effects of regular chocolate eating have to be tempered with the reality that it packs plenty of sugary, fatty calories (particularly those added if you’re dosing yourself with chocolate in the form of whoopee pies or Snickers bars). All those extra calories can quickly pile on extra pounds, easily undoing any good those flavanols might have wrought. It’s still better to keep on thinking of chocolate as a treat, not a treatment.