Patient guide
Carbohydrate Counting and Insulin Guide
This guide helps you estimate the carbohydrates in a meal and work out your insulin dose. It's meant to be used alongside the plan your doctor has already given you — not instead of it.
Before you use this guide
Always confirm with your doctor first. The insulin-to-carbohydrate ratio (ICR) and insulin sensitivity factor (ISF) used in this guide's calculator must come from your own doctor as they are specific to you and change as your pregnancy progresses. This page is an educational tool, not a substitute for medical advice. Never start or change an insulin dose without your care team's guidance.
Understanding Carbohydrates and Insulin
Carbohydrates are the nutrient that has the biggest effect on your blood sugar. They're found in foods like rice, bread, ground provisions, fruit, and anything with added sugar. When you eat carbohydrates, your blood sugar rises — and if you take mealtime insulin, the dose is based on how much carbohydrate you're about to eat. Counting carbs as closely as you can helps you match your insulin dose to your meal, rather than guessing.
Insulin needs change as pregnancy progresses, and they typically increase from around 20 weeks onward as hormone levels rise. A dose that works well early in pregnancy will likely need adjusting later. This adjustment should always be made together with your care team — not on your own, and not based on this guide alone.
Step 1 — Know Your Target Carb Ranges
These are general starting ranges. Your doctor may set different targets for you.
- Breakfast 30-45 g
- Lunch 45-60 g
- Dinner 45-60 g
- Snacks 15-20 g
Step 2 — Estimate the Carbs in Your Meal
Use the table below as a rough reference for common food portions, then add up the carbs across everything on your plate. Note that these values will vary based on your portion size.
| Food | Serving | Carbs |
|---|---|---|
| Rice, cooked | 1 cup | 45g |
| Whole wheat bread | 2 slices | 30g |
| Sada roti | 1 small | 35g |
| Dhalpuri roti | 1 medium | 50g |
| Buss-up-shot | 1 serving | 50g |
| Sweet potato | 1 medium | 25g |
| Dasheen | 1/2 cup | 25g |
| Cassava | 1/2 cup | 25g |
| Corn | 6-8inch cob | 20g |
| Channa (chickpeas) | 1/2 cup | 20g |
| Lentils, cooked | 1/2 cup | 20g |
| Apple | 1 small | 15g |
| Orange | 1 medium | 15g |
| Banana | 1 small | 23g |
| Mango, diced | 1 cup | 25g |
| Watermelon, diced | 1 cup | 12g |
Portion sizes are averages and can vary. If a food comes with a nutrition label, use the "Total Carbohydrate" value listed on the package instead.
Step 3 — Calculate Your Mealtime Insulin Dose
Divide the grams of carbohydrate in your meal by your ICR — the insulin-to-carbohydrate ratio your doctor has given you.
Go to calculatorStep 4 — Correcting a High Blood Sugar After a Meal
If your 1-hour post-meal reading is above your target — commonly 140 mg/dL, but confirm your own target with your doctor — a correction dose may be needed. This is calculated using your ISF, the insulin sensitivity factor your doctor has given you.
Go to calculatorDose calculator
Only use ICR/ISF values your doctor has given you.
Pre-meal dose
—
Correction dose
—
Only use ICR/ISF values your doctor has given you.