Dozens of ketogenic and paleo forums have discussions on the issue. Some of the data fires anxieties, with unsubstantiated claims, a low-carb diet may trigger diabetes instead of reverse it. Some posters from forums even say they have ceased the keto diet because their higher FBGs frightened them so much.
We’ve researched the medical literature and consulted with leading experts. Here’s what you Want to know:
Relax, it is normal — call it “adaptive glucose sparing”
“We definitely see that in people who are doing low carb long term, the majority will find that their fasting blood glucose becomes their highest value of the day,” says Dr. Sarah Hallberg. “They are not actually having issues with blood sugar. They are doing really well. But if you are looking at a log of 24 hours of blood glucose you will see a high first thing in the morning and then a steady decline throughout the day, with no big excursions [in glucose levels] even after meals.”
As regular visitors will know from Dr. Jason Fung and Dr. Ted Naiman, the “pathologic” kind of insulin resistance is caused by higher and higher levels of insulin — hyperinsulinemia — trying to force glucose into over-stuffed cells. That insulin resistance is a prominent feature of type 2 diabetes, polycystic ovarian syndrome (PCOS) and other chronic conditions.
So let’s call physiologic insulin resistance instead “adaptive glucose sparing,” a name that has been proposed by many to reduce the confusion. Dr. Ted Naiman describes it as muscles that are in “glucose refusal mode.”
Prior to converting to the ketogenic diet, your muscles were the major sites to soak up and use glucose in the blood for energy. On the long-term keto diet, however, they now prefer fat as fuel. So, the muscles are resisting the action of insulin to bring sugar into cells for energy, saying, in essence: “We don’t want or need your sugar anymore, so move it along.” Hence, the slightly elevated, but generally stable, glucose circulating in the blood.
Where is that glucose coming from when you consume no sugar and only leafy veggie carbs in your diet? Your liver, through gluconeogenesis — the creation of glucose from non-carbohydrate sources such as lactate, glycerol, and glucogenic amino acids from proteins. It is a natural protective process that got homo sapiens through hundreds of thousands of years of feasts and famines.
“There is no essential requirement for dietary carbohydrate because humans possess a robust capacity to adapt to low-carbohydrate availability,” says Dr. Jeff Volek. In the liver of a keto-adapted person, he notes: “ketone production increases dramatically to displace glucose as the brain’s primary energy source, while fatty acids supply the majority of energy for skeletal muscle. Glucose production from non-carbohydrate sources via gluconeogenesis supplies carbons for the few cells dependent on glycolysis [using sugar for energy.]”
Why are blood sugars highest in the morning? It’s the dawn phenomenon, when cortisol, growth hormones, adrenaline and the enzyme glucagon pulse to the liver to get you up and moving for the day — spurring gluconeogenesis for the cells that need glucose.
“It’s your body making you breakfast,” notes one post that discusses the common phenomenon — except that when your muscles are fat-adapted, they don’t want it.
The HbA1c test estimates the average glucose level in the blood over the previous three months by counting the number of glucose molecules stuck on red blood cells. On a low-carb diet the HbA1c will almost always be lower than the FBG suggests, showing that good glucose control, or type 2 diabetes, is not an issue for that individual.
Insulin is low — an important difference
“We see that in people who are performing low carb long term, most will find that their fasting blood sugar becomes their highest value of the daily life,” says Dr. Sarah Hallberg. “They are not having problems with blood glucose. They are doing very well.
As regular visitors will know from Dr. Jason Fung and Dr. Ted Naiman, the”pathologic” type of insulin resistance is due to higher and higher amounts of insulin — hyperinsulinemia — attempting to force sugar to over-stuffed cells. This insulin resistance is a prominent characteristic of type two diabetes, polycystic ovarian syndrome (PCOS) and other chronic ailments.
So let’s call physiologic insulin resistance instead”adaptive sugar,” a title that’s been suggested by many to reduce the confusion. Dr. Ted Naiman describes it as muscles that are in a “sugar denial manner.”
Before converting to the ketogenic diet, your muscles would be the significant sites to consume and utilize glucose in the blood for energy. On the long-term keto diet, however, they prefer fat. Thus, the muscles have been resisting the action of insulin to put sugar into cells such as energy, stating, in essence: “We do not want or want your sugar anymore, so move it together.” Hence, the slightly elevated, but generally secure, sugar circulating in the blood.
Where’s that glucose coming from if you consume no sugar and just leafy cabbage carbs in your diet plan? It’s a natural protective procedure that got homo sapiens through hundreds of thousands of years of feasts and famines.
“There is no essential requirement for dietary fiber since humans have a solid capacity to adapt to low-carbohydrate accessibility,” states Dr. Jeff Volek. In the liver of a keto-adapted individual, ” he notes: “ketone production increases dramatically to displace sugar since the brain’s primary energy source. At the same time, fatty acids supply the vast majority of energy to skeletal muscle. Glucose production from non-carbohydrate resources via gluconeogenesis provides carbons for the number of cells dependent on glycolysis [using sugar for energy.]”
Why are blood sugar best in the daytime? It is the dawn phenomenon, when cortisol, growth hormones, adrenaline and also the enzyme glucagon heartbeat into the liver for you up and moving to the daytime — spurring gluconeogenesis for those cells which need glucose.
“It is your body that makes you breakfast,” notes one post that discusses the common phenomenon — except that when your muscles are fat-adapted, they do not want it.
The HbA1c test estimates that the average glucose level in blood flow over the previous 3 months restricts the number of sugar molecules stuck within red blood cells.
Understand cortisol and its impact on blood glucose
We all live stressful lives, but some of us have a harder time reducing or releasing our stress. That fact may play out in restlessness, poor sleep, insomnia, or feelings of anxiety or constant tension. Cortisol is the stress hormone that mediates the “fight or flight” physiologic response. And it has a direct bearing on our glucose levels.
“Prolonged cortisol stimulation will raise blood glucose levels,” notes Dr. Jason Fung, who wrote an entire chapter on the stress hormone in his 2016 bestseller The Obesity Code. In it he describes how cortisol, released from the adrenal glands, sends a message to the body to release glucose to prepare for a perceived threat, spurring gluconeogenesis in the liver. In prehistoric times, that surge of glucose energy was usually used up fighting or fleeing from the threat. But in current days, often that stress goes unreleased, the energy not used, which can lead to prolonged higher glucose levels (and higher insulin levels to try to bring it down.)
US nurse Kelley Pound, a low-carb diabetes educator who blogs at the site LowcarbRN, wore a continuous glucose monitor, which tests blood sugars every 5 minutes, to see how various foods and stimuli impacted her blood glucose throughout the day. She discovered that even while eating low carb, it was stress that had the biggest impact on her readings, far more than any low-carb food. “My blood glucose will average 20-30 points higher on mornings where I have not gotten at least 7 hours of sleep,” said Pound, who decided to focus on stress reduction as a key part of diabetes management. “Working so hard to keep blood glucose controlled with diet, only to have it go haywire with stress, is defeating my goals.”
I, too, discovered the same stress impact, especially with sleep. Since this spring, I am doing yoga in the early evening, focusing on other stress-reduction activities (painting and playing my guitar at night rather than scanning Facebook or watching the news) and wearing earplugs and an eyeshade to help ensure a better night sleep. Doing so drops my FBG back into the normal range the next morning.
Drinking a glass or two of wine at night can lower readings, too, because the liver metabolizes the alcohol first before turning to gluconeogenesis, but I don’t want to drink daily.
After doing all this research on fasting sugar levels in low-fat keto ingestion, I’m no longer concerned about my morning highs. Now with a more considerable emphasis on stress reduction and better sleep, they’re routinely in the normal range anyhow. At the same time, I continue to maintain optimal ketosis and enjoy my keto diet and keto daily life.
And by the way, when I finally went for my laboratory test, I got excellent results. My lipids and cholesterol were excellent and my HbA1c was a wholesome 5.3%. “You are the picture of robust health.”