You’ve probably seen people of all ages sipping bright green, frothy drinks. And you may have also noticed an epidemic of juice bars and smoothie stores setting up shop in food courts and organic and gourmet supermarkets — even inside gyms.

What gives? You’ve caught sight of the latest food trend: green smoothies. These cold, thick, shake-like concoctions, which are prepared commercially or whipped up at home in a blender, combine leafy greens and fruit with milk, yogurt and other good-for-you add-ins. Devotees tout them as natural, nutritious and above all, tasty. But do green smoothies live up to their hype? We’ve asked the experts to weigh in.”

Drinking Your Veggies

This is one food fad that has real nutritional cred behind it. “Green smoothies are an excellent way to get your daily requirements of green vegetables, especially if you don’t like the taste of these vegetables or are too busy to cook them,” explains Erin Palinski-Wade, R.D., a nutritionist based in New Jersey. “By blending in naturally sweet yet healthy elements such as fruit and milk, you mask the vegetables’ bitterness while scoring their vitamins and minerals.”

Leafy greens really are nutrient powerhouses. The three types most commonly used in green smoothies — spinach, kale and collard greens — are loaded with vitamins A, C and K, and they have decent levels of some B vitamins, iron and hard-to-get calcium — a mineral crucial for bone health. And unlike many other food-preparation methods, liquefying uncooked greens in a blender doesn’t strip them of their potency. “They retain their fiber too, and because the blender breaks them down, they’re easier to digest than if you ate them raw in a salad,” says Palinski-Wade.

Green smoothies rack up other body benefits too. Fruits commonly added to them, such as bananas, papayas and mangoes, are good sources of potassium — a mineral that helps keep your system properly hydrated. It’s especially important to replenish potassium after a workout, which is why green smoothies are a super post-activity drink, says Palinski-Wade. Plus, the natural sugars in green veggies, fruit and milk, combined with leafy greens’ complex carbs, provide a steady supply of energy, making them an awesome midday snack or on-the-go breakfast, explains Janet Brill, Ph.D., R.D., a nutritionist in Philadelphia.

Understanding the Limitations

On the other hand, smoothies do have drawbacks. Don’t fall into the trap of thinking that drinking smoothies can replace a well-balanced diet with meals that you actually eat—not just drink.

“You might feel slimmer at first, but you’re just losing water weight,” warns Palinksi-Wade. Eventually, you’ll get so hungry for solid food that the fast will backfire.

Another big threat is overloading them with ingredients that pack excess calories. The veggies and fruit, milk or yogurt, plus a handful of nuts or seeds, create a delicious, healthy 200-300 calorie drink. Pile more toppings into your blender, however, and you risk doubling the calorie count, says Brill. Adding whole milk, nuts, seeds, peanut butter or protein powder will turn your healthy smoothie into a fat bomb, she warns. You may find the drink more satisfying when you add in all those other ingredients but for many people, the additions defeat the purpose.  

To keep from going overboard, follow a few easy guidelines. First, stick to a ratio of 60 percent fruit and 40 percent leafy veggies per 16-ounce serving. This ensures it’ll taste sweet while you get maximum vitamins and minerals without exceeding about 300 calories, says Brill. Then, go with a quarter-cup to half-cup of lowfat milk, soymilk, almond milk or lowfat yogurt to give it extra sweetness and thickness. Limit yourself to small amounts of one or two extras: a spoonful of peanut butter, for example, or a handful of sunflower or chia seeds.

“The great thing about green smoothies is that you personalize it to your own taste, but the danger is, they’re so easy and fun to make, you can get carried away,” adds Brill.

Place Your Order Carefully

Juice bars and smoothie stands are raking in big bucks selling green smoothies, but the drinks may carry more calories and fat than you realize. “Check the ingredient lists for added sugar and fruit juice or ask to have your smoothie made without these,” suggests Palinksi-Wade. “There’s enough natural sugar in the fruits, veggies and milk, so you shouldn’t need added sugar to make it sweeter.”