Making an informed decision about continuous glucose monitoring.
As a Registered Dietitian and Certified Diabetes Care and Education Specialist with over 15 years of clinical experience, I’ve witnessed firsthand how blood sugar monitoring technology has transformed diabetes management. I’m Karen Lau, and I’ve helped countless clients navigate the decision between traditional glucose meters and continuous glucose monitors (CGMs) – and today, I want to share what you need to know.
The question I hear most often in my practice is: “What is a CGM? Do I need one?” It’s a great question, and the answer depends on several personal factors that I’ll help you understand today.
How Blood Sugar Monitoring Has Evolved 📊
Blood sugar monitoring has come a long way! We’ve progressed from collecting urine samples and mixing them with chemicals (Benedict’s test) to reliable glucose meters, and now to continuous glucose monitors that give real-time data. Just 10 years ago, CGMs were mainly for people with Type 1 diabetes, but recent research shows benefits for anyone managing diabetes. The technology has become much more user-friendly and affordable – it’s pretty amazing how far we’ve advanced in diabetes care!
Choosing Your Monitoring Method: What You Need to Know 🤔
Regardless of which monitoring method you choose, it’s crucial to track your blood sugar beyond your quarterly doctor visits. While A1C is an important clinical number, it only tells you your average blood sugar over the past 2-3 months – you can’t tell how blood sugar fluctuates during a day. Same A1C may have a completely different blood sugar profile, and you are not able to make quick lifestyle adjustments with A1C alone. This is exactly why daily monitoring, whether through CGM or multiple fingersticks throughout the day, matters – it shows you the real-time patterns that A1C averages can miss.
Several key factors influence which monitoring method works best for you:
How You’re Managing Your Diabetes
If you’re using insulin or certain oral medications: CGMs are recommended for anyone using insulin or insulin-stimulating medications (like glipizide or glimepiride). Those with multiple daily insulin injections or pumps are strongly advised to use CGM – research consistently shows CGMs help these individuals meet blood sugar goals while reducing dangerous low blood sugar episodes.
If you’re using an insulin pump: The CGM of choice may depend on your pump system. Each pump system connects with different CGMs, so this might influence your decision.
If you’re managing through lifestyle and other diabetes medications: More research is being conducted with promising results. In my clinical experience, I’ve seen many clients – whether they’re on medications or managing purely through lifestyle – use CGMs to guide choices they wouldn’t have made without understanding their blood sugar trends.
Clinical Insight: The technology provides data, but interpretation and action planning require professional guidance. I’ve found that clients who work with a diabetes specialist while using CGMs have much more successful experiences.
Cost Considerations
Understanding insurance coverage is crucial for making an informed decision. Currently, Medicare and Medicaid typically cover CGM only if you need at least one insulin injection per day. Test strip allowances vary by management type – those managing through lifestyle alone may be limited to 1 test strip per day.
If you’re paying out-of-pocket, two popular prescription CGMs (Abbott Libre 3, Dexcom G7) currently cost around US$140-160 per month. There’s also an over-the-counter option called Stelo by Dexcom for currently about US$90 per month with no prescription needed – this one is specifically for people with prediabetes or those with diabetes who aren’t using insulin.
Emotional and Psychological Readiness
The decision to use any blood sugar monitoring method is deeply personal. While I believe many people can benefit from CGM technology, it’s not right for everyone. Consider whether more frequent readings might increase your anxiety, if constant blood sugar feedback could negatively impact your relationship with food, and whether you have guidance from a diabetes educator or dietitian to help interpret the data.
What to Expect: CGM Success Tips 🎯
If you’ve decided to try a CGM, here are the most important things I teach my clients to ensure a positive experience:
You Don’t Need Perfect Numbers
Here’s what I tell my clients about realistic goals: for most adults with diabetes, being in the 70-180 mg/dL range about 70% of the time is actually really good! If you’re pregnant, we aim for a tighter range (63-140 mg/dL) for 70% of the time. For Type 2 diabetes and gestational diabetes in pregnancy, while the same glucose ranges apply, specific time-in-range percentages are still being studied – consult your provider for individualized goals. If you have prediabetes and are working to get your levels back to optimal range, the consensus on recommendations is still being studied. Research has found that people without diabetes typically spend 96% of time between 70-140 mg/dL, which gives context for understanding your own patterns.
These are general targets – your doctor may recommend different goals based on your specific situation. For example, older adults or those with certain health conditions may have different targets that prioritize safety over tight management. Always check with your provider to find out what your personal goal is.
Blood Sugar Fluctuations Are Normal
Your CGM line doesn’t need to be flat! Even people without diabetes experience blood sugar variations throughout the day.
Personal Story: From my own experience wearing a CGM (I don’t have diabetes), certain foods still drive my blood sugar high – pizza, mindless snacking on chips and crackers, and yes, dim sum! These fluctuations are completely normal.
Food Flexibility Remains Key
You don’t need to eliminate foods that raise your blood sugar. Instead, you can adjust timing (eat higher-carb foods when you’re more active), modify portions (reduce serving sizes of rice or noodles), balance with other foods (add vegetables and protein to your meals), or stay active after meals (take a 10-minute walk after dinner).
Beyond Food: What Else Affects Your Blood Sugar 🌙
One of the biggest misconceptions I address with my clients is that food and exercise are the only factors affecting blood sugar. Let me share what else impacts your numbers:
Sleep and Stress
Sleep Quality: Poor sleep can raise morning blood sugar levels and affect your body’s insulin sensitivity throughout the day. This is particularly relevant for my clients who are caring for both children and aging parents.
Stress Response: Stress causes the release of hormones that increase blood sugar. You may notice your numbers go higher simply because you’re having a stressful day.
Personal Story: I was wearing a CGM when giving a presentation to diabetes educators. My blood sugar spiked from presentation nerves – stress hormones directly impact blood glucose!
Natural Daily Changes
You’ll notice your blood sugar naturally rises in the early morning hours (around 3-8 AM) – this is called dawn phenomenon. Your body produces hormones that increase blood sugar to prepare you for starting the day. You may even notice your blood sugar stays stable overnight, then increases as you get out of bed. For women, your menstrual cycle may also affect daily blood sugar patterns.
Medication Effects
Certain medications, particularly steroids, can significantly raise blood sugar levels. Always discuss medication effects with your healthcare team when you’re prescribed something new, so you’ll know what to expect and how to adjust your diabetes management accordingly.
The Bigger Nutrition Picture
Here’s something important I remind all my clients: keeping blood sugar in range isn’t the only goal. You may notice that when you eat pork belly or other fatty foods, your blood sugar doesn’t rise quickly. You might also find that high-fat creamy ice cream doesn’t spike your numbers. But this doesn’t necessarily mean these foods are the best choices for overall health.
It’s crucial to remember overall healthy eating principles when making changes to manage your blood sugar. Just because a food doesn’t raise your glucose doesn’t mean it’s supporting your long-term health. We want to find foods and eating patterns that both keep your blood sugar stable AND nourish your body well.
Clinical Insight: In my 15 years of practice, I’ve seen clients who focus solely on blood sugar numbers sometimes miss the bigger picture. The most successful clients are those who use their CGM data as one tool among many, while still prioritizing overall nutrition quality, relationship with food, quality of life, and long-term health and wellness goals.
CGM vs Finger Stick Readings
If you check your finger stick blood sugar and compare it to your CGM reading, the two numbers will rarely be exactly the same. Some difference is normal. If you’re checking when your blood sugar is changing rapidly, the difference will be even more noticeable. This is because CGM readings lag up to 15 minutes behind finger stick readings.
Weighing the Pros and Cons 🤔
Like any technology, CGMs have both benefits and drawbacks. Here’s what I share with clients who are considering making the switch:
The Benefits
Real-time feedback: You can see immediately how food, exercise, stress, and sleep affect your blood sugar, allowing for quick adjustments rather than waiting days or weeks to see patterns.
Better blood sugar management: Research shows people using CGMs often achieve better A1C results and feel more confident managing their diabetes.
Fewer finger pricks: While you may still need occasional meter checks for confirmation, daily finger sticks become much less frequent.
Trend awareness: You can see if your blood sugar is rising, falling, or stable, which helps with timing of meals, exercise, and medications.
Complete picture: A1C shows your average over 2-3 months but misses daily fluctuations. Finger sticks show single moments. CGM fills in the gaps by showing hundreds of data points throughout the day.
Low blood sugar protection: If you experience low blood sugar often or take insulin or insulin-stimulating medications, the alarm will remind you to take immediate action.
Personalized insights: With CGM data showing how different factors affect your blood sugar, we can develop a more tailored management plan for you.
From understanding to knowing: You may have heard what affects blood sugar, but until you see the real-time effects on your CGM, you might not fully grasp the impact. CGM bridges that gap from understanding to truly knowing.
The Drawbacks
Cost: Even with insurance, there may be copays, and without coverage, the monthly expense can be significant.
Learning curve: It takes time to learn how to interpret the data and avoid over-reacting to every number.
Potential anxiety: Some people find constant blood sugar information stressful rather than helpful.
Adhesive challenges: The sensors need to stay attached to your skin for 10-15 days, which can be challenging if you have sensitive skin or are very active.
Information overload: Without proper guidance, the constant stream of information can feel overwhelming rather than empowering.
Alarm fatigue: Without guidance in setting effective alarms, the default settings may be too much for some people.
Constant reminder: Particularly for those newly diagnosed, having a CGM may be a constant reminder of diabetes, which can make the adjustment period more challenging.
Download the complete CGM Pros & Cons comparison guide for a printable reference here.
Your Next Steps: Getting Started with Confidence 📱
A CGM is a powerful tool, but like all tools, it has both benefits and limitations. For the most effective use, I strongly recommend working with a diabetes educator to interpret the data and create meaningful action plans.
Ready to discover your best options for managing diabetes? Here are ways I can support your diabetes management journey:
- Book a Personalized Strategy Call
- Discuss your specific monitoring needs
- Get personalized recommendations for your lifestyle
- Learn about CGM interpretation and action planning
- Using insurance? Book directly
- Join our FREE 8-Day Diabetes Transformation Challenge
- Learn practical strategies that work with your lifestyle
- Understand how to read and respond to blood sugar patterns
- Get daily tips delivered to your inbox
- Download Your Free CGM Decision Guide
👋 About the Author
I’m Karen Lau, a Registered Dietitian and Certified Diabetes Care and Education Specialist with over 15 years of experience helping people manage diabetes while honoring their lifestyle preferences. My background in diabetes care at a major medical institution has given me deep insight into creating personalized approaches to blood sugar management. Want personalized support? Book a free strategy call to learn how we can work together.
Note: This guide provides general education based on current medical guidelines. Always consult your healthcare team for personalized medical advice. This article was authored by me, with my professional expertise, clinical experience, and original ideas forming the foundation of the content. Claude, an AI assistant from Anthropic, helped organize and expand my outline into a comprehensive blog post while maintaining my voice and professional perspective.