Unpacking Your Protein Bar

Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.

Protein bars have their purpose in an athlete’s healthy diet. While whole-food sources tend to be the gold standard for nutrition, protein bars pack a lot of punch for their size and ease. Because they contain carbohydrates, protein, vitamins and minerals in a small treat, they can be used as convenient workout fuel or as a recovery tool. However, knowing what kind of bar is best for your needs and workouts is key.


Whey: Whey protein comes from milk products and is considered the top choice for bioavailable amino acids (the body utilizes it very efficiently). It is high in all nine essential amino acids, in particular leucine, which is a branch-chain amino acid shown to be the most growth-promoting amino acid. Because it comes from milk products, some people may have a hard time digesting it.

Look for: Whey protein isolate, whey protein concentrate, hydrolyzed whey.

Pros: Most readily used by the body for muscle rebuilding.

Cons: Some may be allergic; not vegan.

nutrition bars for runners

Bars you’ll find it in: Hammer Whey Protein Bar, Gatorade Protein Bars, Clif Whey Protein Bars, Power Bar Whey Protein Bars, Tiger’s Milk Protein Bars.

Plant-Based (Brown Rice, Soy, Hemp, Pea): Plant-based proteins oftentimes have a higher fiber content, which can slow digestion, but they also can be more allergen friendly for those that are sensitive to milk-product derivatives. Some plant proteins are void of certain amino acids, but companies will often add them in to get a complete end product. Taste among these different plant proteins does vary but pea protein tends to have the most neutral flavor.

Look for: Pea protein isolate, brown rice protein, soy protein isolate, hydrolyzed soy protein, soy protein concentrate, hemp protein.

Pros: Higher fiber; better suited for those with milk allergies; vegan.

Cons: Lower amino-acid content.

Bars you’ll find it in: Evo Hemp bars, Garden of Life Organic Sport Plant Based Protein Bars, Hammer Vegan Recovery Bars, Kind Protein Bars, GoMacro Bars, Health Warrior Protein Bars, Rise Plant Protein Bar, ProBar Base Bars, Vega Protein+Snack Bars.


Brown Rice Syrup: This sweetener is sugar disguised under a different name. It is made by cooking brown rice with enzymes that break down starches into smaller sugars that are easily digestible and can raise blood sugar quickly. As a quick carbohydrate source, it’s a good option, but in other cases it does not contain any other essential nutrients. Added sugars should be limited to 50 grams, or 12.5 teaspoons, per day. Limit consuming this sweetener to hard workouts and long runs.

Look for: Brown Rice Syrup, Rice Malt Syrup, Rice Malt.

Pros: Quick source of energy during or post hard workout.

Cons: Can cause blood-sugar spikes.

nutrition for running

Bars you’ll find it in: GoMacro Bars, Clif Bars, Health Warrior Protein Bars, Vega Protein+Snack Bars, Pro Bar Base Bars.

Maltodextrin: Usually used as a thickener or filler in foods, as well as a preservative, maltodextrin is a white powder that is highly processed and derived from rice, corn, yeast and potato starch. Considered safe by the FDA, it contains less than 20-percent sugar but can cause a quick spike in blood sugar as it is high on the glycemic index. Limit consuming this sweetener to hard workouts and long runs.

Look for: Maltodextrin, Dextrin.

Pros: Quick source of energy during or post hard workout.

Cons: Can cause blood-sugar spikes.

Bars you’ll find it in: Balance Bars, Tiger’s Milk Protein Bars, Power Bars, Zone Perfect Bars.

Sucralose: Calorie free, this chemically modified sweetener is made by replacing sugar’s hydrogen-oxygen groups with chlorine atoms. This results in a product that is 400 to 700 times sweeter than sugar, but one that has minimal effects on blood sugar. The most well-known sucralose product is Splenda. Some studies show that Splenda may disrupt the microbes in your gut and others claim that it can disrupt your metabolism, but results are unclear. The FDA considers Splenda safe to consume, but if you experience any digestive issues, you may want to avoid it.

Look for: Sucralose, Splenda.

Pros: Calorie free.

Cons: Not a good source of energy
during or post hard workout; could possibly disrupt digestion.

Bars you’ll find it in: Quest Bars.

Sugar Alcohols: These carbohydrates stem naturally or are processed from other sugars; however, they are lower in calories than sugar. Sugar alcohols are partially resistant to digestion and act similarly to dietary fiber in the gastrointestinal tract. In high quantities, they can cause gas, bloating and indigestion. Sugar alcohols have a minimal effect on blood sugar and would be a good choice for those wishing for a quick snack or easy, post-run nosh.

Look for: Xylitol, Sorbitol, Erythritol, mannitol and Isomalt.

Pros: Low calorie; does not affect blood sugar.

Cons: Digestive issues can occur when used in high amounts.

Bars you’ll find it in: Think Thin Bars, Quest Bars.

Other Ingredients

Inulin: Plants produce this dietary fiber which is used as a fat substitute and flour replacer in some foods. Benefits of inulin include promotion of good digestive health, blood-sugar control and fullness.

Look for: Chicory Fiber, Chicory Root Fiber, Oligofructose, Fructooligosaccharides, Fos, Acacia Fiber, Prebiotic Fiber.

Pros: Promotes good digestive health.

Cons: Because it is a type of fiber, too much can cause digestive upset.

Bars you’ll find it in: Garden of Life Organic Sport Plant Based Protein Bars, Hammer Vegan Protein Bar, Kind Protein Bars, Vega Protein+Snack Bars, Zone Perfect Bars.

Natural Flavors: According to the FDA, natural flavors are made by heating and extracting the flavor from animal or plant products. Their purpose is to enhance flavor, not add nutritive value.

Look for: Natural Flavor.

Pros: Calorie free.

Cons: No nutritional value.

Bars you’ll find it in: Organic Garden of Life Sport Plant Based Protein Bars, Clif Bars, Kind Protein Bars, Health Warrior Protein Bars, Rx Bars, Think Thin Bars.

Kylee Van Horn is a licensed Sports Registered Dietitian, 2:49 marathoner and competitive trail runner.

Want to Know What It Takes to Finish at Western States? Just Ask Hellah Sidibe.

Find out what happened when this six-year run streaker and HOKA Global Athlete Ambassador took on an iconic ultramarathon in California's Sierra Nevada