Calculate net carbs from labels.
Net carbohydrate is total carbohydrate minus the fractions the body does not absorb as glucose. Fiber is subtracted in full because it passes through largely unabsorbed. Sugar alcohols are only partly absorbed, so the standard convention subtracts half of them — erythritol is closer to fully non-glycaemic while maltitol raises blood glucose noticeably, making the half-deduction a deliberate middle estimate.
Net carbohydrate
Net per serving = total carb - fiber - (sugar alcohols x 0.5); net total = net per serving x servings eaten
These figures are population-average estimates for general planning only and are not medical or dietetic advice. Individual energy and nutrient needs vary widely with body composition, activity, medication and health status. Consult a qualified health professional or registered dietitian before making significant changes to what you eat, and especially if you are pregnant or breastfeeding, are under 18, or have a medical condition or a history of disordered eating.
Because they differ. Erythritol is essentially non-glycaemic and could be subtracted fully, whereas maltitol has roughly half the glycaemic impact of sugar. Halving is the conventional compromise when the label does not name the specific polyol.
Effectively yes. In the EU and UK, the carbohydrate figure on a label already excludes fiber, so subtracting fiber again would double-count it. Enter zero fiber when using an EU-style label.
Mainly for people on ketogenic or low-carbohydrate protocols and for insulin dosing decisions. On a general diet, total carbohydrate and fiber intake are the more useful numbers.