How to Count Net Carbs on Banting

Net carbs are the carbohydrates that your body digests and converts into glucose: the carbs that count. But how you find that number depends on whether you are looking at a South African label or a US/raw food table.

Here is the golden rule:

• On South African packaged food (Woolworths, Checkers, Pick n Pay): The label lists “Glycaemic Carbohydrates”. Under SA labelling regulations (R. 146), dietary fibre is already deducted and listed on a separate line. Glycaemic carbohydrate is already your net carbs. Do NOT subtract fibre again, or you will undercount your carbs!
• On American imported foods or whole-food databases (USDA FoodData Central): The table lists “Total Carbohydrate”, which includes dietary fibre. Here, the formula applies: Net carbs = Total carbohydrate minus Dietary fibre.

Understanding this single distinction prevents the most common Banting mistake in South Africa: double-subtracting fibre.

Read a SA label in 20 seconds

Turn to the nutrition table and find the Per 100g column first. Ignore front-of-pack marketing claims.

1. Look for “Glycaemic Carbohydrate” (or “Available Carbohydrate”): That is your net carbs per 100g. If a plain yoghurt lists 4.7g glycaemic carbohydrates and 0g fibre per 100g, a 150g tub has 1.5 × 4.7g = 7.1g net carbs.
2. If it’s an imported US product: Look for “Total Carbohydrate”, find “Dietary Fiber” indented underneath, and subtract it: Total Carbs - Fibre = Net Carbs.
3. Scale to your portion: Multiply the per-100g net carb figure by your serving size in grams and divide by 100.

Watch these four traps:

• The double-subtraction trap: If a South African label says “Glycaemic Carbohydrates: 12g” and below it “Dietary Fibre: 8g”, your net carbs are 12g, NOT 4g!
• Total sugars are already inside carbs: “Of which total sugar” is already counted in the carbohydrate line. Never add it on top.
• Polyols (sugar alcohols): Erythritol passes through unchanged and counts as 0g net carbs. For xylitol, count roughly half the polyol grams towards your daily carb limit.
• Hidden starches: Maltodextrin, modified maize starch, and dextrose have a higher glycaemic index than table sugar. A product claiming “no added sugar” can still pack 15g of refined starch per 100g.

“High protein” peanut butters are worth a second look. Some list notably more glycaemic carbs per 100 g than a plain peanut-and-salt jar because of maltodextrin in the ingredients. Compare the carbohydrate line per 100 g on the two jars before you pay for the fancy label.

Numbers you will reuse

Source: USDA FoodData Central. Milk and peanut butter cross-checked against Open Food Facts entries and SA shelf labels.

Milk surprises people. One big glass is 12g net, a quarter of a Banting day. Cream at 3g per 100ml is kinder in coffee.

A simple daily method

You do not need a spreadsheet. Pick a target, many Banting followers aim for around 50g net a day. Log breakfast, lunch, supper and one snack. Round to whole grams.

My paper method: write the four meals, jot net carbs next to each, add at night. After a week you know your repeats by heart. Eggs 0 to 1g, meat 0 to 2g, green veg 2 to 4g, cheese 1g, nuts 2 to 4g per handful. Eating out? Choose grilled meat plus salad and count 8g to be safe.

When you want food ideas that fit the maths, use the Banting food list for beginners and the 7-day Banting meal plan. For brand swaps see banting flour and sweetener swaps. You can also scan a barcode in Banting Buddy to get net carbs without the sums. Tracking and lists are free with ads.

Check numbers yourself in USDA FoodData Central and browse packaged values with attribution on Open Food Facts.

General information only, not medical advice. If you take medication for diabetes or blood pressure, talk to your doctor before changing how you eat.

Last updated: 19 September 2026.