My Keto Quest Bar Experiment



Experiment Summary:

Having recently began eating Quest protein bars, I wanted to know more about the effect they have on my level of ketosis so I set up a 24 hour experiment in which I tested my blood, breath, and urine ketone levels at 11am while fasted, ingested no calories other than three quest protein bars for the entire day, fasted the next morning and tested my ketone levels again at 11am. The results were that my blood ketones went from 1.6 mmol/L the first day to 1.9 mmol/L the following day.

Experiment Details:


What effect do Quest Protein Bars have on my level of ketosis?


Quest Protein Double Chocolate Chunk bars with the current ingredients including soluble corn fiber do not have have enough of an effect on my blood sugar on their own to lower my level of ketosis the following day.


Eating three Double Chocolate Chunk Quest Protein bars and nothing else for one day, my level of blood ketones will be the same or higher at the same time the following day.

Subject Stats:

  • 150lb male

  • Years in ketosis: 3+

  • Last weight lifting session: 1/16/15 (Glycogen stores should be filled at the time of the experiment)

Testing Log:


20 minute walk

11:00am: (Fully fasted at this point)
1.6 mmol/L blood ketone level using Precision Xtra (most relevant)
54 breath ketones using Ketonix breath ketone analyzer (relevancy of breath ketone measurement is still being determined)
1.5 low pee ketones using HealthyWiser sticks (after years in ketosis I always pee out low ketones because my body uses them efficiently)

Ate two Double Chocolate Chunk Quest Protein bars

20 minute walk

Ate one Double Chocolate Chunk Quest Protein bar


11:00am: (Fully fasted at this point)
1.9 mmol/L blood ketone level
60 breath ketone level
1.5 low pee ketones


The results are enough for me to continue enjoying Quest bars for the time being. The main thing I would like to clarify is what effect does soluble corn fiber have on blood glucose over time as it is digested by the gut.

Update: I no longer eat Quest bars and I recommend Chocoperfection instead which tastes even better and is much more ketogenic friendly.


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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.

Clay Owen