Are Costco’s Kirkland Signature Protein Bars Ketogenic Friendly?

At the time of writing this post I’ve been on the ketogenic diet for over four years and logged over 200 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 a ketogenic compatibility grade, and recommend a more ketogenic friendly alternative.


Ketogenic Compatibility Grade: D

Savage Fuel Ketogenic Compatibility 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, avoid or kiss your ketosis goodbye.

Grade Factors:


Costco's Kirkland Signature Protein Bar Macro Nutrient Ratio:

Net Carbs:
3-4 grams of net carbs depending on flavor, one gram of which is sugar.

Estimated Net Carbs: (My estimation based on the caloric values and glycemic index of ingredients
10.5-11.5g of estimated net carbohydrates per bar. 3-4g label carbs depending on flavor + 7.5g from tapioca starch fiber.

Mystery Fiber:
15 grams of fiber from tapioca starch, which is similar to the soluble corn fiber found in Quest protein bars. I recommend estimating half of this fiber as net carbohydrates adding 7.5g to the total. It’s difficult to find good information on this kind of fiber because it almost all comes from the people manufacturing it or putting it in their products and cherry-picking loosely related studies.

21 grams of protein for your body to convert into glucose via gluconeogenesis. Too much protein can prevent ketosis.

Difficult not to overeat due to the sweetness triggering cravings, good taste, and elevated blood sugar from the protein and net carbs causing hunger. As soon as I finish one bar I want another.

Sold by the Box:
Can’t exert willpower at the store or online to buy a single bar as a one time treat.

Costco's Kirkland Signature Protein Bar Keto 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’re just not made with ketogenic dieters in mind because they’re high in protein, low in fat, and have too many ingredients that raise blood sugar and they leave me unsatisfied and craving more.

My Favorite Ketogenic Friendly Dessert


ChocoPerfection blew me away the first time I tried it, the taste and texture were so much better than any other low carb chocolate I’d tried before. I thought it might be too good to be true so I tested my blood ketones one day then ate four bars of it, at the same time the next day my blood ketone reading was even higher than the previous day, I was sold.

I give ChocoPerfection a A ketogenic compatibility grade because of it’s low net carbs (2g per 50g bar), high fat, low protein, zero glycemic index sweeteners, and no mystery “fiber”. The only two downsides of ChocoPerfection are that it is expensive and if you really pig out you’ll most likely become the eye of a fart storm (a side effect of Erythritol and Inulin), both are prices I’m usually willing to pay.

They have 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 also have chocolate chips if you’re into baking and free shipping in the United States.

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