Agar seaweed has 26 kcal per 100 g. Used as a vegan gelatin substitute. Dissolves in hot water and sets into a firm gel. Near-zero calories in typical recipe amounts.
How should I track Seaweed, agar?
Seaweed, agar is a good source of magnesium. For consistent tracking of Seaweed, agar, weigh it raw. Cooking method changes both weight and calorie density — steaming barely changes anything, but roasting with oil or frying can double the calories. A systematic review (Whitton et al., Adv Nutr 2022) found vegetables are omitted from food logs 2–85% of the time, often because people assume they are "free" calorically. While most vegetables are indeed low-calorie, the fats added during cooking are not. Log the oil, butter, or dressing separately to keep your tracking accurate.