CHAPTER 19 — ADVANCED GLUCOSE TRACKING: CGM, PATTERNS, AND DECISION MAKING Glucose tracking can be one of the most powerful tools for improving Type 2 Diabetes — IF it is understood correctly. This chapter explains how to interpret glucose readings, how to use a Continuous Glucose Monitor (CGM) or fingerstick meter wisely, and how to make daily decisions based on patterns instead of isolated numbers. WHY TRACK GLUCOSE Glucose tracking helps you:
- Understand how your body reacts to food.
- Identify foods or meals that cause large spikes.
- See the effect of walking and movement in real time.
- Detect overnight highs or lows.
- Build confidence by seeing improvements within days.
- Work with your healthcare team more effectively.
Tracking is not about perfection — it is about learning. THE TWO MAIN METHODS OF TRACKING 1. Fingerstick blood glucose meter Measures capillary blood sugar at specific moments. Advantages:
- Accurate snapshots.
- Good for fasting and post meal checks.
- Low cost and widely available.
Limitations:
- Does not show continuous patterns.
- Requires finger pricks.
- Can miss night time spikes and dips.
2. Continuous Glucose Monitor (CGM) Shows glucose levels every few minutes via a sensor under the skin. Advantages:
- Shows full day patterns.
- Shows trends (upwards or downwards).
- Shows impact of meals, stress, activity, and sleep.
- Very motivating for lifestyle changes.
Limitations:
- Cost may be higher.
- Readings slightly lag behind blood glucose by 5–10 minutes.
- Not always covered by insurance.
BASIC TERMS USED IN GLUCOSE TRACKING Fasting glucose:
- First reading in the morning before food or drink.
Postmeal glucose:
- Reading 1–2 hours after starting a meal.
Time in Range (TIR):
- Percentage of time glucose stays between target values (commonly 70–180 mg/dL or local equivalent).
Glucose variability:
- How much glucose swings up and down during the day.
Trend arrows (CGM only):
- Show if glucose is rising, falling, or stable.
HOW TO TRACK WITHOUT STRESS You do not need to check constantly. A simple structure is enough: If using a glucose meter:
- Morning fasting glucose 3 to 5 times per week.
- Postmeal readings after different meals to test their impact.
- Occasional bedtime reading.
If using a CGM:
- Review morning summary.
- Look at meal curves to learn which foods spike glucose.
- Check patterns rather than obsessing over single points.
WHAT IS A REALISTIC TARGET General patterns (but always follow your healthcare professional’s advice): Fasting glucose:
- Aim for steady improvement toward a healthy range.
- Do not panic if fasting is harder to control — it is influenced by hormones and liver activity.
Postmeal glucose:
- Ideally rising no more than 30–60 mg/dL (1.6–3.3 mmol/L) after meals.
- Returning toward baseline within 2–3 hours.
Time in Range (TIR):
- Higher is better.
- Many people aim for 70% or more, but even 5–10% improvement is meaningful.
Understanding this prevents unnecessary anxiety. LEARNING FROM MEAL PATTERNS The biggest benefit of tracking is discovering how different meals affect you. Helpful questions:
- Which foods cause the biggest spikes?
- Which meals produce the smoothest curve?
- Does breakfast spike more than lunch?
- Does walking after meals flatten spikes?
Typical patterns people discover:
- Bread, pasta, rice, potatoes cause higher spikes in many individuals.
- Meals with protein + vegetables produce smoother curves.
- Walking for 10 minutes after eating can significantly reduce the peak.
- Eating carbohydrates alone spikes more than mixing them with protein and fat.
Use this knowledge to design meals that work for your body. THE POWER OF POSTMEAL WALKING CGM clearly shows that walking after meals:
- Reduces spike height.
- Helps glucose return to baseline faster.
- Reduces variability.
- Lowers next morning fasting glucose.
Even 5–10 minutes can show a visible effect. OVERNIGHT GLUCOSE AND MORNING FASTING LEVELS Many people discover that fasting glucose is the hardest number to control. Reasons include:
- Dawn phenomenon (morning hormone surge).
- Liver releasing glucose during the night.
- Late night eating.
- Poor sleep quality.
- Stress.
CGM often reveals:
- A gentle rise between 3 a.m. and 6 a.m.
- High evening glucose from late meals.
Solutions:
- Eat dinner earlier.
- Reduce carbohydrate in the evening.
- Improve sleep.
- Add gentle evening movement.
TRACKING DURING STRESS, ILLNESS, OR TRAVEL Stress:
- Raises cortisol -> raises glucose.
- Expect temporary higher numbers.
- Use breathing exercises to stabilise stress.
Illness:
- Body releases glucose to fight infection.
- Hydration and rest become more important.
- Follow sick day rules from your healthcare team.
Travel:
- Time zone changes affect meals and medication.
- Sitting long periods raises glucose.
- Walking during travel reduces spikes.
INTERPRETING SPIKES WITHOUT PANICKING Not every spike is a problem. Occasional peaks are normal. Higher spikes matter when:
- They happen daily.
- They stay high for long periods.
- They push average glucose up.
Lower spikes are usually acceptable when:
- They come from balanced meals.
- They return to baseline quickly.
- They are occasional and predictable.
Use spikes as feedback, not judgment. TRACKING TRENDS OVER WEEKS AND MONTHS More meaningful than day-to-day numbers is the trend over time. Signs of progress:
- Fewer very high spikes.
- Lower morning glucose over weeks.
- Reduced glucose variability.
- Higher time in range.
- Smoother curves after meals.
Plateaus are normal. They are signals to adjust one habit at a time. HOW TO REVIEW DATA WITH YOUR HEALTHCARE TEAM Share:
- Weekly summaries (not every reading).
- Meal patterns that create problems.
- Any hypoglycaemia episodes.
- Questions about medication timing.
Together you can adjust:
- Meal structure.
- Medication doses.
- Exercise timing.
- Sleep and stress habits.
KEY POINTS SUMMARISED
- Glucose tracking increases knowledge, confidence, and control.
- CGM provides continuous patterns; meters provide snapshots.
- Focus on trends, not isolated numbers.
- Postmeal walking is one of the most powerful tools visible on CGM.
- Morning fasting glucose is influenced by hormones, stress, and late eating.
- Tracking reveals which meals and habits work best for your body.
- Use data to adjust food, movement, and routines — not to judge yourself.
Future chapters can offer step-by-step CGM experiments, such as testing specific meals, comparing breakfast types, or measuring the effect of walking.