If you’ve ever vacationed in the tropics, you’ve probably seen people drinking from what looks like peeled coconuts with straws inserted. Now I’m finding more and more skinned coconuts in the fruit and vegetable section of grocery stores. Chop off the top, insert a straw and drink up. Coconut water is becoming so popular that there is now a whole bunch of canned coconut water drinks on the market.

So what’s the deal with coconut water?

Well, I can’t speak to the dozens of pre-packaged products that are showing up (usually sold in cans), but I can tell you what’s found inside the actual coconut. And it’s a nutritional bonanza that could easily be a boon to people trying to control their weight.

One cup of real coconut water contains a measly 46 calories. (Remember, I’m talking about the liquid that occurs naturally inside the coconut, not some “coconut milk” sweetened product — that’s a whole different animal.) It also contains a surprisingly high 3 grams of dietary fiber and 2 grams of protein. Best of all, it’s a fabulous source of potassium — way better than a banana.

Two companies that are marketing excellent commercial products are O.N.E. and Zico, both of which make convenient one-serving containers that are perfect for travel and for the gym. While neither has any fiber, they both contain a whopping 670 mg of potassium as well as four other essential electrolytes.

Both taste great, they’re surprisingly filling and refreshing, and best of all, each contains only 60 calories per serving, way less than the typical “sports drink.”

Lots of nutrients for a very small number of calories. That profile definitely makes it a great drink for a weight management program.