Fiber vs. Net Carbs: What the Difference Means for Your Recipe Labels

The Carbohydrate Breakdown on a Nutrition Label

On a standard FDA nutrition label, the carbohydrate section looks like this:

Total Carbohydrate    28g
  Dietary Fiber        4g
  Total Sugars        12g
    Includes Added Sugars  8g

What's missing? Net carbs — because they're not an FDA-regulated term. They're calculated, not measured.

Net Carbs Formula

Net Carbs = Total Carbohydrates − Dietary Fiber − Sugar Alcohols

Fiber and most sugar alcohols are not absorbed by the body in a way that raises blood glucose. That's why the keto community subtracts them — and why diabetics track net carbs rather than total carbs.

Using the example above: 28g − 4g fiber = 24g net carbs (no sugar alcohols present).

Types of Dietary Fiber

• Soluble fiber — dissolves in water, slows digestion, lowers blood cholesterol (oats, beans, psyllium)
• Insoluble fiber — adds bulk, speeds transit time, prevents constipation (whole wheat, nuts, vegetables)

Both types have 0 net carbs for keto purposes.

Sugar Alcohols: Partial Subtraction

Not all sugar alcohols are equal. Erythritol has ~0.2 cal/g and is typically subtracted fully. Maltitol has ~2.1 cal/g and should only be half-subtracted. Read labels carefully when using sugar alcohol sweeteners in recipes.

Why This Matters for Recipe Labels

If you're creating nutrition labels for keto, diabetic, or low-carb products, accurate carbohydrate reporting is legally required. The FDA considers a label misleading if net carb claims are unsupported by actual fiber and sugar alcohol content.

RecipeCalc calculates dietary fiber and total sugars automatically. For every recipe, you get a complete carbohydrate breakdown that feeds directly into our FDA-style nutrition label generator.