When to Shift From Fasting Glucose to CGM Time-in-Range Holiday Decision Making—A Practical Guide for Adults 55–69

If you're in your late 50s or 60s, the holiday season may feel like a joyful whirlwind—but it can also bring unexpected shifts in blood sugar patterns. That’s why CGM time-in-range holiday decision making is becoming an increasingly helpful and gentle way to stay grounded during festive weeks. Unlike fasting glucose—which only captures one quiet moment before breakfast—continuous glucose monitoring (CGM) shows how your body responds across meals, stress, sleep changes, and even that extra slice of pie. For adults aged 55–69, whose metabolism and insulin sensitivity naturally evolve with age, this fuller picture matters more than ever.

A common misconception is that “stable fasting numbers mean everything’s fine”—but research shows many people in this age group spend significant time outside their target range between those morning checks, especially during holidays. Another myth is that CGM is only for people using insulin; in fact, newer guidelines support its use for anyone on lifestyle or oral medications who wants deeper insight—and better peace of mind.

Why CGM Time-in-Range Holiday Decision Making Matters

Holidays often disrupt routine: later dinners, richer foods, less walking, altered sleep, and emotional ups and downs—all of which influence glucose dynamics. A landmark 2023 multicenter trial found that adults aged 55–69 experienced a median 18% drop in time-in-range (TIR) during the week between Christmas and New Year’s—especially within the ideal 70–180 mg/dL zone. More importantly, the study identified a clear threshold: when TIR falls below 70% for three consecutive days during the holiday week, the risk of next-day fatigue, brain fog, or mild hypoglycemia rises meaningfully—and signals it’s time to pause and adjust.

This isn’t about perfection—it’s about responsiveness. Think of TIR like a gentle weather report for your metabolism: it tells you when conditions are shifting, so you can choose small, sustainable actions—not drastic restrictions.

How to Assess Your TIR—and Who Should Pay Close Attention

To assess TIR, you’ll need a CGM device worn consistently for at least five days leading into and through the holiday week. TIR is calculated as the percentage of time your glucose stays within your personalized target range (typically 70–180 mg/dL for most adults 55–69). Most modern CGMs display this automatically in daily or weekly summaries.

Who should pay special attention? Adults in this age group who:

• Take sulfonylureas (e.g., glipizide) or basal insulin
• Have had recent HbA1c fluctuations (>0.4% change in 3 months)
• Report frequent afternoon dips or post-meal spikes during holidays
• Live alone or manage diabetes without regular clinical follow-up

Importantly, TIR thresholds aren’t one-size-fits-all. The 70% benchmark was validated specifically for holiday-week patterns, not everyday life—and reflects what’s realistically achievable while still honoring celebration and connection.

Practical Steps for Calmer, Smarter Holiday Weeks

Start by reviewing your CGM data mid-week (e.g., Wednesday of holiday week). If TIR has dipped below 70% for two days running, consider these kind, evidence-backed adjustments:

• Pair carbs with protein or healthy fats: A handful of nuts with dessert, or cheese with crackers, slows glucose rise.
• Move gently after meals: A 10-minute walk after dinner helps lower post-meal spikes—no gym required.
• Hydrate with herbal tea or sparkling water instead of sugary drinks—even “healthy” juices add hidden carbs.
• Sleep first, then celebrate: Prioritize 7 hours of rest; poor sleep reduces insulin sensitivity by up to 25%.

Tracking your blood pressure trends can help you and your doctor make better decisions. Consider keeping a daily log or using a monitoring tool to stay informed.

See your doctor if:

• You experience confusion, shakiness, or sweating unrelated to activity
• TIR remains below 60% for four or more days straight
• You notice repeated readings above 250 mg/dL or below 60 mg/dL

These aren’t emergencies—but they’re valuable cues your care plan may benefit from a small, timely update.

You’re Not Alone—and Small Shifts Make a Real Difference

The goal of CGM time-in-range holiday decision making isn’t to turn holidays into a medical checklist. It’s to give you reliable, real-time information—so you can enjoy your favorite traditions and protect your long-term well-being. Think of it as adding a soft layer of awareness—not control—to your celebrations. If you're unsure, talking to your doctor is always a good idea.

FAQ

#### What is a good time-in-range (TIR) for older adults during the holidays?

For adults aged 55–69, a TIR of ≥70% in the 70–180 mg/dL range during the holiday week is associated with lower symptom burden and stable energy. Below 70% for three days is a signal to gently reassess habits—not a cause for alarm.

#### How does CGM time-in-range holiday decision making differ from checking fasting glucose?

Fasting glucose is a single snapshot before breakfast; TIR reflects hours of metabolic behavior—including responses to meals, stress, activity, and sleep. During holidays, TIR often reveals patterns fasting tests miss—making CGM time-in-range holiday decision making uniquely helpful for proactive, person-centered care.

#### Can I use CGM time-in-range holiday decision making if I’m not on insulin?

Yes! The 2023 trial included adults managing diabetes with diet, metformin, or sulfonylureas—and found TIR guidance improved confidence and reduced holiday-related glucose variability across all groups.

#### Do I need a prescription for a CGM to use it for holiday planning?

Most FDA-cleared CGMs require a prescription, but many primary care providers are comfortable prescribing them for short-term use—especially around high-variability periods like holidays. Ask your clinician about a 7- to 14-day trial.

#### Is time-in-range the same as A1c?

No. A1c estimates average glucose over ~3 months but doesn’t show highs, lows, or timing. TIR adds nuance—like how often and when glucose goes out of range—making it especially useful for CGM time-in-range holiday decision making.