You may have seen the health hype: Photos of athletes sipping from a coconut shell while they tout the healthy benefits of coconut water — from boosting your metabolism to hydrating you post-workout. But is coconut water the be-all and end-all of sports nutrition and weight loss? And what about coconut milk?

Coconut milk comes from the flesh of the coconut. It’s high in calories and most of those calories are derived from fat, including saturated fat (the type we should only use sparingly), explains Bonnie Taub-Dix, RD, author of "Read It Before You Eat It" and a nutrition expert in New York.

Look for fat content and note the amount of saturated fat in coconut milk – each 450-500 calorie cup contains about 50 grams of fat, of which 45 grams is saturated.

“Many people confuse coconut milk with coconut water. The water is a thin liquid that is high in potassium and often used as a source of fluid to quench hydration,” says Taub-Dix. Coconut water is much lower in calories than coconut milk.

Coconut water is about 45 calories per cup whereas coconut milk contains about 500 calories. (That’s six times what you'll find in a cup of skim milk — so a dairy replacement it is not.)

While the milk is a delicious, sweet cream often used in mixed beverages, smoothies and cooking, if you’re watching your weight or have a history of heart disease or elevated cholesterol, you’ll want to limit your intake.

Coconut milk contains iron, selenium, sodium, calcium, magnesium, phosphorus, potassium, protein and vitamins C, E, B1, B3, B5 and B6. “But the vitamins and minerals provided don’t outweigh the negative calorie and saturated fat content,” says Taub-Dix. And most of the health benefits are either myth or have been confused with coconut water.

Coconut water, on the other hand is the newly touted sports drink, flying off shelves in gyms and yoga studios as the next hot thing. A report from New Nutrition Business says sales of coconut water doubled in 2011 and will reach an estimated $110 million nationwide.

Yet people who live where coconuts grow have long drunk the sweet, nutty elixir of the coconut, the water that builds inside the shell of a young coconut. As the fruit ages, the water solidifies into the white meat and is pressed for milk or oil.

But is coconut water really any better for you than regular water?

Coconut water does contain sodium and potassium, two minerals that help balance fluids after exercise. “It is lower in calories than coconut milk and high in potassium, so it can be a good beverage to help hydrate,” says Taub-Dix. But while it may provide a salt and potassium wallop, it’s not a magical cure. Some of the claims being touted are that the drink boosts metabolism, helps with weight loss and replaces electrolytes better than sports drinks.

A study in Medicine & Science in Sports & Exercise found coconut water replenishes body fluids as well as a sports drink and better than water but that athletes preferred the taste of sports drinks. Beyond that, studies don’t suggest that coconut water lives up to its hype of healing disease or promoting weight loss.

For instance, there’s plenty of potassium in food and you’ll get all you need from eating a healthy diet rich in bananas, potatoes, kidney beans, spinach and lentils. And sports drinks, only needed if you’ve exercised vigorously for more than an hour, are still excellent hydrators at half the price.

“I think people look for miracle cures and fixes in any new product,” says Taub-Dix. “I wouldn't rely on coconut water to boost metabolism or drop pounds.”

If you like the taste of coconut water, it won’t hurt to indulge (unlike with coconut milk, which should be reserved for limited occasions.)

If you’re going to drink it and can afford it (most brands cost $2-3 per serving), look for unsweetened varieties and check that they don’t contain more than 60 calories. The ingredients should say 100 percent coconut water. Cans, bottles and packages should be BPA-free.

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