Ready for a healthy smoothies reality check? At one fast food restaurant, a 250-calorie low-fat strawberry-banana smoothie contains a whopping 38 grams of sugar. Translation: Roughly 9.5 teaspoons of sugar, just a fraction of a teaspoon less than in one 12-ounce can of cola. That means about 60 percent of the calories in one seemingly healthy smoothie comes from sugar.

The American Heart Association recommends that men consume no more than nine teaspoons of added sugar a day, and women consume no more than six teaspoons. Male or female, indulging in these healthy smoothies puts folks of either gender over this limit right away.

What’s more shocking: This food chain in question didn’t load up their concoction with heaping teaspoons of granulated sugar. They sweetened their “healthy smoothies” in more natural ways—with fruit juice, juice concentrates and fruit purees. But, doesn’t that make it healthier? Not if the bulk of the calories comes from sugar, natural or not.

Even scarier? You may be making the same kind of mistake with your homemade “healthy smoothies.”

Here are five ways you may be wrecking your healthy smoothies:

1Flavored Yogurt

One popular brand contains 12 grams of sugar, largely from sweetened fruit purees, often made with added sugar.  And, it’s actually one of the saintlier brands, touting less sugar than the competition. Yet, that’s still three teaspoons of sugar in one cup. You probably never even added that much to your morning coffee. Blending plain yogurt with unsweetened fruit, fresh or frozen, is a much better option.