You get up, stretch, reach for your ketone meter and strips and excitedly conduct the first test of your blood ketone levels for the day. But instead of finding high blood-ketone levels, your ketone levels are surprisingly low, even though you stayed on your keto diet the night before, went to bed in ketosis, and have “fasted” ever since. Why?
Don’t worry. It has nothing to do with what you have or haven’t done. What you’re likely experiencing is called the “dawn phenomenon” or “dawn effect.”
What is the Dawn Phenomenon or Dawn Effect?
The high-blood-sugar dawn phenomenon is a naturally occurring, early-morning increase in blood sugar levels (glucose) that occurs for pretty much all humans, even without excessive consumption of carbohydrates or being on a ketogenic diet; it is not associated with food consumption, it has to do with biological processes called gluconeogenesis and glycolysis. It’s believed that the release of other hormones, such as cortisol, during the wee hours of the morning may play a part.
For some people, the elevation of morning blood-glucose levels is significant. For others, it’s barely noticeable. Regardless, you won’t even notice if you don’t give yourself a blood test for ketone readings. Plus, it’s a normal response by the body as it prepares to face the day. It’s not dangerous to people with diabetes or anyone else. There’s nothing you can or should do about it, other than take it into consideration if you test yourself for ketones (and glucose) first thing in the morning. (The dawn phenomenon is the reason we recommend you wait until you’ve been awake an hour or two before testing to get a truer reading of your nutritional ketosis.)
The Dawn Phenomenon and Diabetes
People with prediabetes or type 2 diabetes experience more insulin resistance and may or may not secrete enough insulin to optimally counter the dawn phenomenon. Those who don’t secrete enough will see their blood glucose rise more than others during the early morning hours. Keto dieters with diabetes who want to reduce the impact of the dawn phenomenon can do so by avoiding foods with sweeteners and eating very low-carbohydrate meals or snacks before bedtime (this is great for managing insulin levels too).
Want more details on the dawn phenomenon? Watch our video to learn more about the dawn phenomenon or read about the science behind the dawn effect.
