If you've grabbed an energy bar for a quick snack lately, you're not alone. About 40 percent of us eat them regularly.

But as the new Consumer Reports testing reveals, that convenient snack might not deliver the boost you expect.

The key to choosing a healthy bar isn't just looking at the calories - it's checking what's actually inside, like the added sugars and ingredients. The best options contain whole foods like nuts, seeds, whole grains, and dried fruit.

Consumer Reports dietitian Amy Keating oversaw CR’s testing of 31 popular bars, checking nutrition and taste. CR’s tests show some winners and duds in every category.

For fruit and nut bars, the Patterbar stood out with its complex flavor and chewy texture. It contained more fruits and nuts than the Nature Valley bar, which fell short of what testers described as a dry, tough consistency.

Kind's whole-grain bar got high marks for its moderate sweetness with hints of coconut and honey, but Bobo's Oat Bar Original got low marks as it has more than twice the added sugars of the Kind bar. It tasted mild and slightly underbaked.

In the protein category, the 88 Acres bar impressed testers with its sweet and slightly salty mix featuring real pumpkin seeds, which give it its protein, as opposed to more highly processed isolates like in the Think bar, which testers also thought tasted bland and had a slightly bitter aftertaste.

When shopping for your next bar, CR says to look for:

? Bars with no more than 7 grams of added sugar

? Real sources of protein like nuts and seeds rather than soy or pea powders

? And fiber from whole grains rather than added fiber

So, read the label before you grab that energy bar for your afternoon pick-me-up. What looks like a healthy snack might be closer to dessert.

And if you’re wondering how much sugar is too much, the American Heart Association recommends that women limit added sugars to 25 grams per day and men limit it to 36 grams.