MEAL BOLT: A Tutorial for Insulin Dosing

✅ Step 1:
M — Measure the Meal

Goal: Understand what you're about to eat.

🔍 What to do:

  • Estimate total carbohydrates

  • Consider protein and fat content

  • Identify glycemic index/load of the meal
    (e.g., fast carbs like juice vs. slow carbs like lentils)

🧠 Why:

  • Carbs determine immediate insulin needs

  • Fat/protein can delay glucose rise (leading to late spikes)

  • High glycemic meals spike faster than low glycemic ones

Example: A plate of pasta with cream sauce and chicken = high carb + high fat → may need more insulin, but delivered over time.

✅ Step 2:
E — Evaluate Yourself

Goal: Take a quick snapshot of your current internal environment.

🔍 What to consider:

  • Current BG (from CGM/BGM)

  • Insulin on board (IOB) — any insulin still active?

  • Activity — are you about to exercise? Did you just? Will you be sedentary after the meal?

  • Stress, hormones, illness?

🧠 Why:

All these factors shift your insulin sensitivity up or down.

Tip: After cardio, you may need less insulin. During a stressful day or illness, you may need more.

✅ Step 3:
A — Add the Base Units

Goal: Calculate the meal bolus for carbs.

🧮 How to calculate:

Carbs ÷ Insulin-to-Carb Ratio (ICR)

Example: Eating 60g carbs, ICR is 1:10 → 60 ÷ 10 = 6 units

🧠 Why:

This gives your base bolus — it covers the food, not corrections or delayed digestion.

Step 4:
L — Layer a Correction

Goal: Add (or subtract) insulin based on your current BG.

🧮 How to calculate:

  1. (Current BG − Target BG) ÷ Correction Factor (CF)

  2. Subtract IOB if needed

Example:
BG = 200, Target = 100, CF = 50
→ (200−100) ÷ 50 = 2 units
→ If IOB = 1 unit → 2 − 1 = 1 extra unit to correct

🧠 Why:

Correction boluses address high blood sugar. But subtract IOB to avoid stacking insulin.

✅ Step 5:
B — Build the Bolus Shape

Goal: Decide how to deliver the insulin — all at once or spread out.

⚙️ Options:

  • 100% upfront for fast-digesting meals (e.g., cereal, fruit)

  • Combo or square wave bolus for slow-digesting meals (e.g., pizza, creamy pasta, steak)

Example: 60% upfront, 40% over 2 hours for high-fat meals

🧠 Why:

Fat and protein slow digestion. Spreading insulin helps match that slower spike.

✅ Step 6:
O — Offset the Timing

Goal: Decide when to bolus.

⏱️ Options:

  • Take insulin 0–30 minutes before eating, depending on the type of food and your personal experience with how insulin works for you

  • Split, combo or square wave bolus if you're unsure or eating slowly

Example: High GI food? Pre-bolus 20–30 minutes.
Low GI or large meal? Consider split or delayed dosing.

🧠 Why:

Matching insulin timing to food absorption helps reduce post-meal spikes.

✅ Step 7:
L — Look at the CGM

Goal: Watch how your body responds in real-time.

⏰ Spot check at:

  • 1 hour → Was there a fast spike?

  • 3 hours → Any delayed rise?

  • 5 hours → Any lingering effect from fat/protein?

Tip: A flat CGM line = a great match.
Spike then drop? Could mean too little pre-bolus or delayed digestion.

✅ Step 8:
T — Tweak for Next Time

Goal: Use what you learned to improve future boluses.

✍️ What to log:

  • What you ate

  • How much insulin and when

  • What your BG curve looked like

  • What you’d do differently next time

Example:
“60g of Chinese food, gave full bolus up front. Spiked at 2h → Next time: 50% upfront, 50% over 2 hours.”

🧠 Why:

Diabetes is pattern-based. Learn from every meal to build mastery over time.

Summary

M – Measure the Meal (carbs, fat, protein, glycemic impact)
E – Evaluate Yourself (BG, IOB, activity, stress)
A – Add the Base Units (carbs ÷ insulin-to-carb ratio)
L – Layer a Correction ((Current BG − Target) ÷ CF – IOB)
B – Build the Bolus Shape (upfront % vs. extended %)
O – Offset the Timing (pre-bolus lead time or split dose)
L – Look at the CGM (check curve ~1h, 3h, 5h)
T – Tweak for Next Time (log & adjust based on results)