Are Costco’s Kirkland Signature Protein Bars Keto Friendly?

At the time of writing this post I’ve been on the ketogenic diet for over five years and logged over 250 blood ketone tests in an effort to estimate the effects of food and ingredients on my ketosis, including those in protein bars like Costo’s Kirkland Signature brand.

I think ketogenic dieters naturally gravitate towards protein bars looking for a convenient sweet treat that won’t kick them out of ketosis, but are protein bars the right place to look? In this post, I’ll evaluate Costco’s Kirkland Signature protein bars, give them keto friendly grades, and see how they stack up to other low carb treats!


Savage Fuel Keto Friendly Grades:

  • A: Completely compatible, positive or no impact on ketosis.

  • B: Highly compatible, but don't go too crazy.

  • C: Moderately compatible, be mindful and limit intelligently.

  • D: Barely compatible, detrimental to ketosis and not recommended.

  • F: Not compatible, overdo it just a little and kiss your ketosis goodbye.

Keto Friendly Grading Factors:

  • Net Carbs per Serving: How many carbs are in this thing?

  • Net Carbs per 100 calories: Since serving sizes often vary significantly, a net carb per 100 calorie ratio is a more consistent measure of keto-friendliness than net carbs per serving. Lower ratios are also an indicator of higher fat content because fat has more calories per gram than protein and carbohydrates.

  • Sugar: Sugars have a higher glycemic index and larger negative impact on ketosis than other carbohydrates.

  • Hidden Carbs: Hidden carbohydrates are based on the caloric values and glycemic indexes of ingredients sometimes classified as fibers or sugar alcohols.

  • Easy to Overeat: Some foods are easy to over-eat and require extra willpower to limit overeating which is an important factor to consider.

  • Nutritional Density: Foods that are relatively high in net carbs per 100 calories but are high in nutrition per calorie can still be worth eating like broccoli and cauliflower.


0-1 GREAT, 1-2 OK, 2-3 CAUTION, 3+ RED ALERT

Costco Kirkland Signature Protein Bars Keto Friendly Grades:

Overall factors: +1-2 hidden net carbohydrate estimate from the 15g of tapioca fiber which we don't know how much it affects blood glucose. Also low nutritional density and very easy to overeat factored into grades.

  • Chocolate Chip Cookie Dough: D
    3g Net carbs per 190 calorie 60g bar
    1.6 Net carbs per 100 calories (Yellow)
    1g Sugar

  • Chocolate Peanut Butter Chunk: D-
    4g Net carbs per 190 calorie 60g bar
    2.1 Net carbs per 100 calories (Yellow)
    2g Sugar

Cinnamon Roll: D-
4g Net carbs per 180 calorie 60g bar
2.2 Net carbs per 100 calories (Yellow)
2g Sugar

Chocolate Chip Cookie Dough: D
3g Net carbs per 190 calorie 60g bar
1.6 Net carbs per 100 calories (Yellow)
1g Sugar

Costco Kirkland Signature Protein Bars Keto Friendly Conclusion:


Costco’s Kirkland Signature protein bars have a lot going for them. I like their taste, chewy texture, and they have quality ingredients like unsweetened chocolate, cashews, Erythritol, sunflower lecithin instead of soy lecithin, and stevia.

Unfortunately, they were just not made for the keto diet because they're high in protein, low in fat, a bit too high in carbs, and are difficult to not overeat, especially when they sell them by the box. If you're like me, you discovered Costco's Kirkland Signature protein bars not looking for a high protein snack, but a tasty sweet treat that wouldn't kick you out of ketosis. Let's compare Kirkland's protein bars to other more keto friendly sweet treats:


Kirkland Signature Protein Bars vs ChocoPerfectioin, Nui Cookies, and Keto Bars


As you can see, when comparing Kirkland Signature protein bars to the best keto-friendly treats out there by net carbs per 100 calories, which is the most consistent indicator of keto friendliness, Kirkland bars are just not at the same level, and this chart doesn't include the hidden net carbs in tapioca fiber.

So in conclusion I recommend going with more keto friendly sweet treats like my personal favorite ChocoPerfection.


Chocoperfection has a lot of great flavors too, dark and dark mint are my favorites and Raspberry is the only flavor I don’t like. The dark mint with a handful of macadamia nuts tastes just like thin mint cookies. You get the classic mint chocolate flavor with the salty and crunchy macadamia nuts, it’s my favorite ultra low carb dessert.

If you’re interested in trying some I’d recommend getting the variety pack and a pack of the dark chocolate so you can try all their flavors and still have more of the dark which you’re going to like anyways. They have free shipping in the United States too which is sweet.

For more expertly curated and guaranteed keto friendly products check out the Keto Shop!


Note: Links used here are affiliate links. By buying through the links I may receive a commission for the sale. This has no effect on the price for you.

Disclaimer: I am not a doctor. Please consult a medical professional before making any medical decisions. These are my personal opinions based on years of practicing the ketogenic diet.