We know that eating a variety of whole foods from all food groups is the ideal way to eat. But we also know that sometimes life just gets in the way of our best laid plans. That’s when having a nutrition bar in your bag or glove compartment can save the day.

In a perfect world, nutrition bars would be just what their name promises: a bar loaded with a variety of beneficial nutrients, but low in less desirable ingredients, like sugar, saturated fat and refined foods. And, of course, it would taste great. But which bars meet those criteria?

Today’s nutrition bars run the gamut from simple fruit and nut concoctions to protein, vitamin and mineral powerhouses, and everything in between. Reading labels can be very helpful in figuring out what bars meet your specific needs, be it high protein, high fiber, low sugar, low saturated fat, or unrefined. Knowing what you want from your nutrition bar will help you choose. For a pre-workout snack, a protein-rich bar with adequate carbohydrates is beneficial. And if you want a snack to hold you over until the next meal, choose a high-fiber, low-sugar bar.

Here are some tips to keep in mind when grabbing your emergency nutrition bar.

1. Read the ingredients list. Some nutrition bars contain alternative sweeteners to keep calories low. Another common ingredient is inulin or chicory root fiber to boost grams of fiber. While there’s nothing wrong with these types of ingredients, both have been known to cause gastrointestinal problems in some people. You may want to avoid these bars if you have issues.

2. Check the serving size. Most bars are considered an entire serving. However, some consider half a bar to be a serving; eating a full bar would mean you’re doubling your intake of all the nutrients.

3. Beware of glorified candy bars. Some bars contain up to 6 1/2 teaspoons of sugar, which is more than a chocolate bar. Note that those packed with fruit will contain naturally occurring sugar, so look for sources of added sugars, such as cane sugar or brown rice syrup, in ingredients lists. High levels of sugar in fruit-less bars represent added sugars.

Heidi McIndoo, M.S., R.D.