Protein intake experiment and postprandial Ketone levels

(Scott Telfer) #1

Just an N=1 that I thought I might share for those of you interested. I’ve long been convinced of carnivore and adopted it intermittently over the years and almost perpetually of late.I have always been wary of the protein / GNG warnings and that a high level of protein being detrimental to an effective and efficient ketotic state. I decided to stop pontificating and just do an experiment on myself for which I hypothesised would throw me out of meaningful ketosis for at least 12 hours.

I fasted and ate an entire pork shank which weighed over 900g with the bone. I don’t believe in calorie counting or macros really but for the experiments sake it would have been about 1500 calories, about 80g of fat and over 160g of protein sans the bone.

I ate in one sitting and gnarled every piece of flesh, fat, collagen, skin and tendon off of its bones - it was delicious!

I’m 35, male and about 69-71kg. Received wisdom and advice on Keto suggest is that I should have about 56-87kg of protein per day to fall in to the ‘moderate’ category.

Pre Pork shank and around 15 hours fasted blood ketones
-2.8 mmol/l
30 mins postprandial
-1.4 mmol/l
2 hours postprandial
-1.2 mmol/l
3 hours
-1.3 mmol/l
6 hours (before sleep)
2.5 mmol/l

I’m genuinely shocked at the relatively minimal impact on blood ketone levels having ingested what many follow ketonians would deem double a daily allowance in one sitting.

I may repeat the experiment with a leaner cut of meat and see what happens.

I will test my ketones one hour after I rise tomorrow, just incase there’s some delayed effect I’m yet to observe.

Thanks for reading :slight_smile: have a great week!

(Bob M) #2

I’m not shocked at all. I’ve eaten massive amounts of protein and much lower fat than you did, and the effect on my blood ketones was low to non-existent.

(bulkbiker) #3

As quite a few of us have said quite a few times GNG is a demand driven process… The body will create the glucose it needs but not more so your blood sugars won’t rise not your ketones drop too much with large amounts of protein intake.
Haven’t seen you around for a while… welcome back!

(Bob M) #4

Also, testing ketones is problematic. I have thousands of tests, and (1) they aren’t accurate, (2) hydration affects them, (3) time of day affects them, (4) exercise affects them, (5) etc. So, if I test in the mornings, I always get low values, which go up over the course of the day. What this means is you have to have a “run in period”, where you test using a “normal” diet/exercise routine, and test multiple times during that period. Then, start another test period, and test around the same times you did before. And even then, you can’t be 100% sure the changes you see (if any) are real changes or the vagaries of testing.

(Carl Keller) #5

I’d be more interested in the blood glucose levels following 160 grams of protein, not that I expect it to be higher than if you ate moderate protein. Most days I eat 150-200 grams of protein and I’m down 4 pounds this month.

(Elizabeth ) #6

Dave Feldman wore a continuous blood glucose monitor and saw flatline the entire time he was eating carnivore and wearing the monitor. You can’t even tell where he ate.

#7

In a healthy person, the blood glucose should remain constant as a sign insulin and glucagon are balanced. Anything that skews this relationship, like some carbs or metabolic abnormalities, will change the reaction one way or the other. In order to keep blood glucose level, the insulin is working to push the glucose stimulated by glucagon into muscle and/or fat cells. Lipolysis, and therefore beta oxidation, will be decreased at the same time. No net gain or loss in blood concentration.

A 50% decrease in ketones is significant. I think the same experiment performed on someone who has minimal ketones to begin with would not recover as quickly.

(Adrian ) #8

Yes, agreed. 2.8 to 1.2 mmol/L is not ‘minimal impact on blood ketone’, it’s significant
My bet is that high protein will also lower his fasting ketones the next day(s), so it’d be interesting to keep measuring