Ask DrH and you may be answered – Vol 2

In the second segment of AskDrH, I received a question about a ketogenic diet. So I decided to ask Jimmy Moore, who has written and few books on ketogenic diets to respond.

“Dear Dr. H,
I presently test my blood for the presence of Ketones using a blood monitor meter. My question is when is the best time of day for testing blood ketones; at night or in the morning? I’ve read two separate reports with opposite opinions. One said AM and the other said a more accurate reading will result at the end of the day. What is your opinion?
Hey Karen, that’s a really fantastic question. The best time to test your blood ketones to see where you stand is after you get out of bed from an overnight fast. Your morning ketone reading on the Precision Xtra blood ketone monitor will tend to be your lowest reading of the day. It should be definitely above 0.5 mmol and ideally over 1.0 mmol. Then, if you choose to test again later in the day, make it at least four hours after your final meal of the day (i.e., if you eat supper at 6:00pm, then test your blood ketones at 10:00pm). This allows for the blood sugar response to come back to baseline and you get the most accurate reading. This number will tend to be about double what your morning reading was. So if your morning ketones were 0.7 mmol, then you can expect your evening ketones to be around 1.4 mmol. It’s not an exact thing, but this gives you a good guide. If there are readings that fall well below this, then perhaps you should test again just to make sure and evaluate what you ate, your stress level, how you slept, and any medications you are taking that could be impacting your ketones. Additionally, testing your blood sugar while testing for the blood ketones will give you an indication of how well you are doing since higher blood ketones generally will result in lower blood glucose levels. I hope this information helps!
Jimmy Moore, Livin’ La Vida Low-Carb
Jimmy Moore is an author who has written books that include:


Do you have any other questions for the AskDrH series?
If so send them to
  • Karen

    Thank you both for responding and clarifying the information!