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We tried all of Costco’s store-brand protein bars, and there was a clear winner. Find out which bar our editors loved the most and why.

Reviewed by Dietitian Mandy Enright, M.S., RDN, RYT

Key Points

• With the right ingredients, protein bars can be a great snack to tide you over to your next meal.
• Kirkland’s Peanut Butter & Semisweet Chocolate Chip Chewy Protein Bar won our editors over.
• It’s chewy, crunchy and just the right amount of sweet, plus loaded with protein and fiber.

Costco is loaded with healthy, delicious snack options—fruit bars and pistachios are just a few of our favorites. And some of the best high-protein snacks you can buy are protein bars. Protein is an essential macronutrient that plays a major role in keeping your body functioning and healthy. Snacking on a protein bar is an easy way to add more protein to your diet while also keeping you satisfied between meals.

To help you find the tastiest protein bar, we decided to try all of Costco’s store-brand offerings. The Kirkland Signature line had four bars available, and one of them came out on top—the Peanut Butter & Semisweet Chocolate Chip Chewy Protein Bar.

Our testers were impressed with the flavor of the bar, which features a combination of peanuts, peanut butter, chocolate chips, almonds and almond butter. Protein bars can sometimes have an artificial, lingering aftertaste, often due to ingredients like sugar substitutes and/or sugar alcohols, but that wasn’t the case here. Instead, the nutty, sweet flavor of the bar had several of our testers saying, “Yum!”

Our testers not only thought this bar tasted great, they also thought it looked appealing and had great texture too. You can clearly see the ingredients in the bar, from the mini chocolate chips to the bits of peanuts, which they thought made this bar more appetizing. Keeping the ingredients whole also added to the bar’s texture, as the crunch of the peanuts and smooth chocolate coating blended together nicely. The chewy, crunchy texture helped this bar stand out, especially compared to the others that were taste-tested, which featured a pureed mixture of ingredients that led to a one-dimensional texture.

Nutrition Information

Our registered dietitians also liked the nutritional content of these bars. Here’s the nutrition information for a 1-bar serving:

• Calories: 190
• Carbohydrates: 16 g
• Fiber: 6 g
• Total Sugar: 6 g
• Added Sugar: 4 g
• Protein: 10 g
• Total Fat: 11 g
• Saturated Fat: 3 g
• Cholesterol: 0 mg
• Sodium: 120 mg

Our dietitians found the combination of protein and fiber to be most impressive for a snack that will help you feel full between meals, whether you’re looking for a mid-morning or afternoon bite. As a bonus, these bars are also gluten-free, so they’re perfect if you’re following a gluten-free diet.

What To Look for In a Healthy Protein Bar

When looking for a healthy protein bar, there are several things to consider:

• Whole-food ingredients: Look for whole-food ingredients, like dried fruit, nuts, oats, egg whites, nut butters and seeds.
• Protein and fiber: You also want a bar with a protein-fiber combo, which helps fill you up more compared to a bar that’s lacking these ingredients. Look for a bar with at least 10 grams of protein and at least 3 grams of fiber.
• Low added-sugar content: A little sugar in your bar is okay and will help provide some energy—just makes sure it’s less than 10 grams of added sugar if possible. Ideally, look for bars with natural sugar sources, like dates, maple syrup and honey.
• Artificial ingredients: Artificial sweeteners and sugar alcohols, are ingredients that you want to limit. Sugar alcohols can be especially bothersome for those with IBS, causing unwanted gas and bloating. Maltitol, sorbitol, erythritol and xylitol are commonly used sugar alcohols, while common artificial sweeteners include aspartame, sucralose and acesulfame potassium (ace-K). Natural non-nutritive sweeteners are a better choice, including stevia and monk fruit.

Other Costco Protein Bars We Tried

Costco’s Kirkland Signature Protein Bars had three other flavors that we tried: Chocolate Brownie, Chocolate Chip Cookie Dough and Chocolate Peanut Butter Chunk. The major issue our testers had was the flavor. These bars, unlike our favorite one, use stevia, a no-calorie sweetener. While stevia is a natural sweetener that doesn’t affect blood sugar—which can be a great option for people with prediabetes or diabetes—a major downside is that some people experience an unpleasant bitter aftertaste with it. Our testers felt like it overpowered the other ingredients in the bar.

These bars also weren’t as visually appealing and were too chewy at times for our testers. We recommend opting for our top pick protein bar or another snack from Costco—like mini fruit bars and walnuts.

Our Expert Take

Kirkland’s Peanut Butter & Semisweet Chocolate Chip Chewy Protein Bar took top spot in the Costco protein bar throw down. Its texture, flavor and nutrition content won our editors over. This bar has a great combo of fiber and protein to help fill you up and keep you satisfied. The texture is a perfect balance of chewy and crunchy, and because it’s sweetened with sugar, it doesn’t have the weird bitter aftertaste that stevia sometimes leaves. Grab a box or two of these bars to have on hand today!