No contest, energy bars win hands-down as a convenient, grab-and-go food. But many of these portable treats don’t rate so well as healthy sources of nutrients. Many of them are packed with hidden sugars, salt and fats, and way too many calories are unaccounted for on their labels.

One nutritionist calls energy bars nothing more than “dead food” that lack nutritional value. In response, some experts suggest making your own energy bars from as few as two nutritious ingredients, such as raw or roasted nuts (do it yourself in an iron skillet) and pitted, dried medjool dates you pulse in a food processor, press into a pan and chill overnight. The next morning, cut into small squares, wrap in wax paper and store the morsels in a tightly sealed container.

But if you must grab one of those prepackaged bars, the rule of thumb when selecting energy bars is to find one that has fewer than 5 grams of fat, 3 to 5 grams of fiber and a calorie count that won’t bust your gut. What’s more, don’t depend on these bars to meet your overall nutritional needs, experts caution.

Grab healthy, whole foods, such as an apple, and go!