Welcome to Keto Sister. Last week’s post explained what happens to blood glucose levels as a result of eating a ketogenic diet. In sum, blood glucose (also known as blood sugar) decreases and is replaced in large part by a new fuel source, ketone bodies. Humans are always being fueled by two energy substrates: glucose and fatty acids. A person who eats a high carbohydrate diet burns more glucose as fuel, and a person who eats a high fat diet burns more fat as fuel. However, there is never a time at which a person stops burning one or the other. The implication for someone eating a low carb diet is that the body never replaces all glucose utilization with ketone bodies. Instead, the body reduces its glucose needs to the bare minimum and then it makes any needed glucose not taken in through the diet through gluconeogenesis. This is the normal, healthy process of fueling the body in the absence of dietary glucose.
Elevated Blood Glucose
There are many benefits of ketogenic nutrition when a ketogenic diet is implemented correctly. One of the benefits of eating low carb is blood glucose control, and this can be a big benefit to those who struggle with type 2 diabetes and obesity.
As I mentioned last week, ideal blood glucose levels are between 81 and 109 milligrams per deciliter (see this post for details). However, it is a common occurrence for those following a very low carb diet to have elevated blood glucose levels. I mentioned the first two causes last week, but there is a third that is rarely discussed by those in the low carb arena. Admittedly, these concepts are not well understood by most people. Nevertheless, here is what we know about elevated blood sugar levels in ketosis:
Physiological Insulin Resistance (PhIR). Eating a low carb diet in and of itself can induce a type of insulin resistance. How is that possible? When a person reduces dietary carbohydrates drastically, the body adapts quickly to the reduction in carbs and can think that it is experiencing a glucose deficiency. PhIR occurs in this instance to ensure that there is enough glucose to fuel the brain. The brain signals the rest of the body to reduce its sensitivity to insulin. This makes it so that the glucose that circulates in the blood stays in the blood rather than being taken up by muscles and for other functions that would normally pull glucose out of the blood. Instead, glucose remains available to the brain and for a few other essential functions that require glucose, such as in the thyroid and red blood cells. PhIR is often detected by an elevated fasting glucose, taken first thing in the morning before any food has been eaten. A PhIR-induced elevated blood glucose often comes down after meals because the intake of nutrition signals the body that more glucose is coming.
PhIR is a protective mechanism in the body, a survival mechanism, to help the body survive what is perceived as a temporary deficiency. While we know that the short term effects appear to be relatively harmless, the long term consequences of this state are unknown. The fact is that PhIR is still insulin resistance. If someone with PhIR were to take a glucose tolerance test, the person would fail miserably. Thank goodness this does not happen often, but I find any condition that induces insulin resistance and elevated blood glucose to be troubling. Whether it is PhIR or “actual” insulin resistance, elevated blood glucose is not an ideal state for too long (again, see this post for details). One way to eliminate this is to increase carbs in the diet. PhIR is most likely to happen to people eating 20-30 grams net carbs per day for months or years on end. I have advised clients to increase carbs to the highest level they can tolerate, depending upon their ultimate goals. Usually when people who were eating 20 grams carbs increase to 40-50 grams per day, PhIR disappears. When the body realizes that there is glucose available, it often ceases the signal of insulin resistance and fasting glucose levels come down.
Elevated cortisol. Eating a ketogenic diet can be a stressful state for the body. While its benefits are well documented, reducing glucose signals the body to make both ketones and glucose to meet the body’s needs. In periods of heightened stress response, such as illness, overtraining, poor sleep, undereating, excessive fasting, etc., the body continually produces cortisol. One of cortisol's functions is to signal the body to create excess glucose in the liver in response to emergency signals that glucose is needed to deal with the stress. In a stressed state, glucose needs can be increased so elevated cortisol makes sure that extra glucose is available just in case it is needed. One way this manifests is when a person has a food allergy or sensitivity. I wrote a post on this topic (see here), so I will not cover this in length here. But know that this is a form of stress that often manifests as elevated blood sugar, usually 30-90 minutes after eating the offending food. See this post for more details.
Glucose that is elevated due to excess cortisol is not as consistently or easily determined as PhIR. Glucose may be elevated in the morning after an all night fast. It may be elevated midday, after meals, after a workout, after feeling stress, and even at bedtime. Over time, chronic heightened stress response can tax the body to the point that it drops everything instead. High cortisol, high blood glucose, high blood pressure, even high energy can turn into low cortisol, low blood sugar, low blood pressure, and serious fatigue. This state is also known as adrenal fatigue, although it rarely has anything to do with the function of the adrenal glands. Adrenal fatigue is a state of unmanaged stress in the body.
Addressing elevated blood glucose due to a stress response is a complicated process because elevated blood sugar is just one symptom. This was my experience a few months ago when I was hit with a wave of fatigue so strong that it reminded me of how I felt after my children were born.
Here is what I did (and still do in some cases) to manage stress:
- Rest more. I always make sleep a priority, climbing into bed by 9:30 pm each night and allowing myself to rest until 5:30 or 6:00 am. But I gave myself more rest periods during the day. As a mother of two, wife and someone busy doing research, I cannot always stop and sit or lay down through the day. But I can take time to meditate for small moments throughout my day: while making breakfast, in car line while waiting to drop my kids off at school, before entering the grocery store, etc. A meditation can be as simple as closing my eyes, taking a deep breath and saying “thank you for this moment.” Remembering to say thank you is a good way to bring a smile to my face, and that tiny gratitude signals my heart that I am feeling good. Feeling good and stress cannot occupy the same space at the same time. 😉
- Eat within one hour of waking up. I used to fast until my day was half over. I have stopped this practice now that I understand what a significant stressor this has been for my body. I am fairly lean, about 22% bodyfat, and my body is sensitive to signals it gets from food. If I eat within minutes of waking, I feel calmer and more energetic through the day. This practice alone stabilized my blood glucose levels within a few days.
- Replace coffee or caffeinated tea with lemon balm tea. Caffeine increases stress and anxiety. Lemon balm is very calming and helps the body to better handle stress while increasing alertness (see this post for details).
- Consider adding supplements to help the body manage stress, such as magnesium, ashwagandha, and vitamin C.
True insulin resistance. Eating a low carb diet can also result in pathological (what I call "true") insulin resistance. Wait, what?
There is quite a bit of speculation over this topic, but scientists like Chris Masterjohn, Ph.D. and Stephen Guyenet, Ph.D. are brilliant scientists who have discussed insulin at length on their respective blogs. Turns out that insulin resistance and subsequently elevated glucose levels are not always cured by eating a low carb diet. In some instances, insulin resistance is triggered when a cell determines that it has too much energy (as fat or glucose, the type of energy does not matter). It decides there is not room or need to take in extra glucose, so it ignores insulin signals to open the cell for storage and instead leaves additional glucose in the bloodstream. This instance explains how eating too much fat can lead to insulin resistance.
However, it can also make determining the threshold for eating “too much fat” tricky. I eat a lot of protein, I am a busy wife, mother, researcher and nutrition consultant, and I sometimes deal with stress and do not sleep well. For these reasons, I have absolutely no idea how much energy I burn day to day. My diet alone increases my resting metabolism because I eat a lot of protein (which is thermogenic), and I also get lots of sunlight, laughter and rest. Eating less protein, getting less sunlight, feeling stress or sadness, and fatigue can all slow the metabolism. Thus, my day to day calorie expenditure levels change based upon these and other factors like weather, movement and food quality to name a few. I do have a general idea of how much energy I expend per day and how much food I need. I make a point of eating enough so that my metabolism stays activated without eating so much that I have to contend with energy excess. Unsure how much food you should be eating? Refer to this post as a starting point. If your goal is to gain rather than lose, then I would increase by 300-700 calories per day rather than decrease intake.
Pay Attention to Blood Glucose
Even if you are eating a low carb diet, it is important to pay attention to your blood glucose levels. Many people in the low carb arena use glucometers to measure glucose and ketone levels at home, while others have their doctors regularly test their three-month glucose levels (HbA1c), insulin, cortisol and other tests. Eating a low carb diet is a good start to bringing these levels to healthy levels in the body. Once blood glucose stabilizes and a person feels well, he or she can monitor how s/he feels as an indication of wellness day to day. However, occasion glucose monitoring can help to avoid getting stuck in one of the three above scenarios in the future. I hope this helps you understand your own blood glucose levels, how to interpret those readings and what to do one of the above situations happens to you. Thanks for reading.