Resources Blogs

The Myth of Controlling Blood Sugar, And a Better Way to Manage It

Woman with Diabetes Looking Out to Mountains

Contributor: Riva Greenberg

Almost everyone who has diabetes – I’ve had type 1 for 51 years – has been told to control their blood sugar. I’m here to tell you it’s not possible. But before you think, “Oh, no!” let me assure you that this is the best news you could hear. 

Now you can stop blaming yourself for your numbers. They are not your fault. Our blood sugar levels rise and fall throughout the day and night as the result of numerous interacting variables, most of which you can’t control. Think about it: How often have you groaned when your blood sugar was higher or lower than you expected – and you did everything “right!”

I’m not saying you can’t manage your blood sugar; you can. But “control” means you can do something and get an exact, intended result. You can’t do that with blood sugar. I cannot, for example, see 142 mg/dl (7.9 mmol/l) on my continuous glucose monitor, decide I want to be 102 mg/dl (5.7 mmol/l), and make it happen. Yes, I’ll either take some insulin or a walk, but I cannot guarantee exactly where my blood sugar will settle.

Control comes from a machine paradigm. Machines are built for precision, accuracy, and operational excellence – you pull a lever and get a predictable result. The idea that we can manage blood sugar with that kind of control reflects a mechanistic view Western medicine often has of the human body.      

Let yourself off the hook of control. Instead discover how to better work with your blood sugar by ‘seeing, shaping and shifting’ your numbers. It’s likely your A1C and time in range will improve, and you’ll feel more powerful and less stressed.    

Why can’t we control blood sugar?

Let me first make it perfectly clear – the fact that you can’t control blood sugar is not due to any personal failure. It’s not because you don’t try hard enough or because you eat things you “shouldn’t”, or because you don’t exercise enough. It is because of two primary factors.

  1. Biological: You are a biological organism. Our heartbeat, blood pressure, signalling between gut and brain, digestion, nerve impulses, liver processes and more – interact with each other and influence blood sugar levels. So does our nervous system. For example, stress hormones both raise and lower blood sugar. So, while you can perform actions that positively influence your blood sugar, the numbers you get are partly from your body’s own uncontrollable, dynamic, ever-fluctuating metabolic functions. 
  2. Complexity: Our interactions with our unpredictable world affect our blood sugar. For example, I may plan to walk an hour, and then it rains, and I don’t walk. This impacts my blood sugar. I order my meal in a restaurant and pre-bolus, so I take my shot as soon as the waiter walks away. Fifteen minutes later he returns to tell me the kitchen has had a fire and it will take another twenty minutes to bring out the food. Need I say by then, my blood sugar will be too low? 

Blood sugar is an emergent property of a complex, biological organism living in a complex, unpredictable world. Whoever came up with, ‘Man plans and God laughs’ was probably looking at his glucose number! 

We can apply simple rules for diabetes management when the situation is simple. For example, ‘Rule: if blood sugar is dangerously low, eat some glucose tablets if you can and/or call 911.’ But in complex situations, like managing the ever constant fluctuations of blood glucose, complexity science dictates to try something and see what happens.


 For a great list of impacts on blood sugar see Adam Brown’s ‘42 Factors that affect Blood Glucose’. My daily bug-a-boo is the Dawn Effect. If I don’t get up immediately when my eyes pop open in the morning to inject a unit of rapid acting insulin, to blunt the rise of blood sugar that will follow, I’ll be up 30 points in no time.  Naturopathic doctor, CDE, type 1 Jody Stanislaw wrote a great article that further informs why blood sugar cannot be controlled, “The Many Reasons for High and Low Blood Sugars” (and why we need a LOT of compassion for ourselves!) 


By now, you probably agree there is no magic formula for “controlling” blood sugar. Not even carb counting, or as a friend once so eloquently put it, ‘carb guessing.’ Success in managing your blood sugar is knowing how to influence, nudge and navigate any number you see. It’s easy to remember with this mantra: ‘See, Shape and Shift.’ 

See your numbers: Check your blood sugar frequently on your meter or CGM to see where you are. You can’t know how or what direction to move in if you don’t know where you are. And since you now know that blood sugar is a dynamic, emergent property, it’s not wise to leave it on its own for too long. What’s also important is how you view your numbers – not as a test, but as a useful guide. No judgment, that’s a must. 

Shape your actions: Choose actions/habits that will have you spend more time in range. How do you know? By checking how different meals, the duration and type of exercise, when you’re feeling stressed or don’t get a good night’s sleep, affect your blood sugar.  

A useful tool is ‘Testing in Pairs.’ You check your blood sugar before and two hours after meals and exercise, also when you wake and before you go to sleep. You are looking for how your blood sugar changes after a specific meal, exercise or event. Structured testing is checking and recording your blood sugar in this way six to seven times a day for three days in a row. It can give you and your health professional invaluable information. Seeing how what you do affects your blood sugar can help you adjust your actions or make new choices to keep your blood sugar in range more often. 

Shift your numbers: Either discuss with your health professional or learn through your own experimentation how to nudge and navigate your numbers up or down. For example, maybe it works better to split your insulin dose before and sometime after a high-fat meal. When your numbers are out of range (70-180 mg/dL) shift them up with fast-acting carbohydrates like glucose tablets or down with insulin or exercise.  

It’s time we stop telling people they can control their blood sugar. Our numbers emerge from dozens of interacting variables, not our actions alone. Work with your blood sugar as you learn to see, shape and shift your numbers, and see how freeing it feels to give up the burden of control.  


Riva Greenberg is a diabetes advocate, health coach, author, advisor and inspirational speaker. Her work is dedicated to helping people with diabetes and health professionals work collaboratively in a way that helps both flourish. Riva has written three books, hundreds of articles and her blog, DiabetesStories. She spent ten years as a peer-mentor, and this year celebrates 51 years of living successfully with type 1 diabetes.

Written by

Riva Greenberg
Riva Greenberg Diabetes Advisor, Inspirational Speaker and Thinking Partner
Woman with Diabetes Looking Out to Mountains
You belong here Join today.