Powdered sugar has 389 calories per 100 g – identical to granulated sugar. It is simply milled to a finer powder, sometimes with ~3% cornstarch as anti-caking agent. The smaller particle size dissolves faster but does not change glycemic response.
How should I track Sugar, powdered?
When tracking Sugar, powdered, measuring by weight on a kitchen scale gives you the most precision. Volume measures vary depending on crystal size and powder density — a heaping spoonful can be double a level one. Research shows visual estimation errors reach 50–200% for calorie-dense foods (Almiron-Roig et al., Appetite 2013), and liquid sweeteners like honey are among the easiest to over-pour. For zero-calorie sweeteners, bulking agents add trace calories (2–4 per packet) — negligible in your daily total. For calorie-containing sweeteners, the scale is essential.