“Just count your carbs, use your insulin-to-carb ratio to calculate your dose, and voila! Your blood sugars will be perfect!”
…said by no person actually living with type 1 diabetes, EVER.
I have been teaching people with type 1 diabetes around the world for the last ten years what it really takes to achieve healthy blood sugar levels. I’ve also been successfully managing my own T1D since 1980. And I’m here to say, keeping blood sugars in a healthy range is a LOT more complicated than most T1Ds are ever taught.
In this article, I will attempt to cover the many variables, far beyond just carbs, that can affect one’s blood sugar level. Before I cover the many non-food variables, let’s quickly touch on why carb counting alone does not work.
All Carbs Are Not Created Equal
First of all, all carbs are not created equal. If you eat 30 grams of carbs from pineapple, it will raise blood sugar much, much faster than 30 grams of carbs from a low glycemic food, like black beans. Yet timing of how to dose for different types of glycemic foods is rarely taught. The dose for the pineapple will have to be given much further in advance than the dose for the beans. Pre-dosing will allow the insulin to be closer to peaking when the pineapple is being absorbed, which is important since it will cause blood sugar to spike within just a few minutes. The beans, however, might need a split dose. For those on a pump, you’ll want to use an extended bolus, or if on MDI, perhaps 1 unit now and 1 unit an hour later, due to their much slower effect on blood sugar.
How Fiber Plays a Role
Then there is the issue with fiber. Insoluble fiber is the roughage found in many vegetables and whole grains. This type of fiber doesn’t get digested, thus does not affect blood sugar, so we do not have to count this type when calculating carbs. When a label shows how much fiber is in the food, it’s usually 50% insoluble and 50% soluble. Soluble will affect blood sugar, so it is suggested to subtract half of the total grams of fiber from the total carbohydrate count.
Protein and Fat
What about protein and fat? Many people think protein and fat are ‘free’ foods. That is not true. Many will see a slow and steady rise in blood sugar 2-5 hours after eating protein. High-fat meals can cause an increase in insulin resistance for 5-10 hours requiring a temporary basal increase for hours after the meal. This is easily seen with meals like pizza, anything with a lot of cheese or cream, or even after eating a large amount of healthy fats, like avocados and nuts.
The Effects of Caffeine
Coffee doesn’t have any carbs, right? Yes, but it has caffeine, which many studies have shown causes an increase in insulin resistance and a release of adrenaline, which will raise blood sugar. Caffeine is tricky. Some type 1s always see a rise in BG and some don’t. Usually, coffee is consumed in the morning, when blood sugar tends to rise anyway, so it can be hard to tell if the rise is being caused by dawn phenomenon (the natural rise in morning blood sugar caused by the liver’s secretion of glucose) or the caffeine. To help determine this, I suggest drinking black coffee without sweeteners on an empty stomach later in the day, and watch if BG rises or not. But the tricky thing is, even in the same person, sometimes a rise in BG is seen from caffeine, and sometimes not.
Water and Dehydration
Water certainly does not have carbs, right?! Of course not. But not drinking enough water can result in a higher blood sugar. What?? Here’s why: When you are dehydrated, the amount of water in the bloodstream decreases, which makes the existing glucose in the bloodstream more concentrated. While the amount of sugar in your bloodstream hasn’t technically increased, it can result in higher blood sugar level readings because the ratio of sugar to water has increased.
Furthermore, dehydration increases the level of the hormone vasopressin, which pushes the liver to produce blood sugar. Mild to moderate levels of dehydration—especially during hot weather, intense exercise, or illness (diarrhea or vomiting)—can cause blood sugar readings to increase by 50 to 100 mg/dL or higher. When dehydrated, insulin will take effect slower due to it having a harder time absorbing, thus causing a delay in the effect of a bolus.
As if all of that wasn’t confusing enough, there’s more!
When Insulin Becomes Less Effective
If insulin gets too hot or if it freezes, it can lose potency. If the bottle/pen has been open longer than 28 days, it can also lose potency. Anyone who is not good at rotating pump or shot locations on their body has a high risk of scar tissue buildup, and if delivering insulin into scar tissue, this will cause a very frustrating delay and/or reduction in the absorption of the insulin.
The Role of the Liver
The liver is a constant source of glucose streaming into the bloodstream (thus one reason why we need long-acting insulin/basal insulin in our bodies at all times). The liver’s glucose output peaks in the morning hours, or any period of prolonged fasting. It also peaks with any event that causes a release of adrenaline, as well as after an extreme low blood sugar. These types of blood sugar rises are very hard to manage because the amount of glucose the liver is releasing is frankly unpredictable.
Speaking of hormones, women’s cycles can also affect blood sugar. Many women will have an increased need for insulin 1-7 days prior to the start of their cycle and a reduced need on day one. Having said that, every female with type 1 should track their BG trends around their cycle to determine what is true for them. Women going through perimenopause, as well as teens going through puberty, will also see an increase in insulin resistance, which can be very frustrating due to its sporadic nature. Some doctors recommend the drug Metformin to mitigate this.
Feelings of stress, anger, and nervousness all release cortisol, which will cause resistance to insulin and a need for more insulin. This can be dramatic if someone suddenly sees police lights in the rearview mirror, or gets a disturbing text, for example. I have seen my own blood sugar spike up over 100 points in under thirty minutes in situations like this. Stress also affects the way we take care of our diabetes.
Chronic stress will also raise blood sugar, but more subtly. This effect can also be seen the day after a poor night’s sleep. Physical stress, like taking an extremely cold shower, can also raise BG. I shot up to 300 after shivering for ten minutes during an ice-cold shower.
Anytime we get sick, the body releases stress hormones like epinephrine (also known as adrenaline) to fight the illness. These hormones can raise blood sugar levels and increase the amount of insulin the body needs. This can also be seen in people who get seasonal allergy symptoms.
Some medications can cause an increase in insulin resistance, such as steroids, some antidepressants, some BP lowering meds, nicotine, estrogens, birth control pills, niacin, and more. Some can decrease resistance, like Ritalin and beta-blockers. Alcohol can actually lower blood sugar, due to the fact that the liver will reduce glucose output to focus on breaking down the alcohol. Yet, this can be hard to see since alcohol is often mixed with sugars and/or eaten at mealtimes, which will raise your glucose levels.
Any increase in body weight will cause an increased need for insulin, and vice versa in the case of weight loss, even if just by a few pounds.
CGMs and meters often are not 100% accurate and in today’s high-tech world, it’s easy for us to forget this. If a finger used for a blood sample is dirty or wet, this can alter the reading too. If there are bubbles in the pump tubing or if an infusion set accidentally comes out, this will obviously cause blood sugar to rise.
The only time in 40 years with T1D that I ended up in the ER with diabetic ketoacidosis (DKA) was due to exactly this. I ran a half-marathon in the morning and then treated myself to a very high carb dinner. As I finished dinner, I started to feel very sick. I assumed I was just tired and dehydrated from my long run. Soon all of my muscles started to cramp and I felt super nauseous. I became so hot that I remember gingerly rolling myself off the couch to lie down on my tile floor to cool down. I soon realized I needed help. I crawled to the phone and dialed 911. It was not until I was in the ambulance that I realized my entire tubing was full of bubbles.
Warmer temperatures cause blood vessel dilation, which can cause an increase in blood flow to the muscles, and thus a drop in BG. The same can be seen after a hot shower or time spent in a hot tub. Some report that cold weather drives glucose numbers down – perhaps related to the body working harder to stay warm. Yet, when you go to an environment with a different temperature, many other factors may be changing, such as your activity level, what you are eating, hydration, etc.
Though most studies related to diabetes and altitude concern the accuracy of blood glucose meters, there are some reports that altitude can increase insulin resistance. However, if you are going to a high altitude to ski or hike, for example, the extra activity can of course drop BG.
It’s easy to think exercise will always drop blood sugar, but this is actually not true. INJECTED INSULIN is what causes hypoglycemia, not exercise alone. This is very helpful to understand. I did not learn this until after living with T1D for 20 years and had very frustratingly stuffed my face with tons of carbs every time prior to being active throughout my childhood. When you fully grasp this concept, it is truly possible to exercise without eating anything!
Every low is caused by excessive injected insulin. Exercise enhances the effect of insulin. For exercise to cause a low, there must be enough injected insulin in the body for the exercise to activate to cause a low.
If exercise alone caused hypos, then every person who ever exercised would have to deal with low blood sugars, but that is clearly not true. To illustrate this, if someone with type 1 wakes up with a high blood sugar and immediately goes on a walk to bring it down, the BG will likely not come down. Why? Since there has not been a bolus since the night before and the only insulin on board is basal or long-acting, this small amount of insulin will likely not be enough insulin in the body for the walk to cause a low. If anything, it could make the dawn phenomenon worse and actually cause BG to rise.
So the advice to ‘always eat before exercise’ really depends on how much insulin you have on board and what your blood sugar is. The less insulin, the less chance of a low, and vice versa. However, the type of exercise also creates different blood sugar effects.
Anaerobic exercise, such as weight lifting and high intensity interval training (HIIT), can actually initially raise blood sugar due to an increase in glucose production in the body during these types of activities. However, during steady-state cardio – like a long walk, elliptical, or bike ride – glucose utilization predominates, thus there is a greater chance of lows with steady state cardio over anaerobic activities.
With anaerobic exercise, as well as a steady state activity lasting over two hours, something called delayed onset hypoglycemia (DOH) can occur. This is due to the fact that during these activities, a lot of stored glycogen in the muscles gets used up. Thus after the activity completes, the body can be busy for hours replenishing the body’s muscle glycogen storage reserves, thus removing glucose from the bloodstream without the need for insulin. Knowing this is very important because many often think that once they stop being active, their risk of having a low goes away, but not in this case.
Case in point. I completed an intense, seven-hour gravel bike race a few summers ago, and I needed to reduce my basal rate for 48 hours after the ride. Had I not known about DOH, I could have suffered a serious low that night as I slept.
In the life of a type 1, calculating accurate rapid doses is our most challenging task. It is a task that must be done daily, multiple times a day, every day of our lives, from the day we were diagnosed, today, tomorrow, and until the miracle of some sort of cure is discovered. Having said that, when you have the right education and support, managing type 1 and staying in range over 70% of the time is absolutely doable.
About the Author
Dr. Jody Stanislaw received her Doctorate in Naturopathic Medicine in 2007. Her TEDx talk, Sugar is Not a Treat, has over 2.8 million views. She has successfully managed living with type 1 diabetes since the age of 7 and now shares her wisdom helping T1Ds all over the world.
Via her virtual Type 1 Diabetes consulting practice, over the past 10 years she has helped thousands of patients all over the world achieve the best blood sugar control of their lives. In addition to teaching patients how to improve blood sugar levels, she also supports patients with key lifestyle areas such as diet, exercise, sleep, and emotional health, which are critical but often left out of standard care.
She has presented over 200 Facebook lives since March 2020. Her videos have thousands of views. Testimonials sharing how her content has dramatically improved people’s lives are endless.
From her 40+ years of personal plus professional experience with type 1 diabetes, she teaches life-changing information about how to successfully manage this complex condition that standard medical care often leaves out. She has private programs, online courses, and a monthly T1D training program.
For more info, visit: www.DrJodyND.com