Spinach has 23 kcal and 2.2 g fiber per 100 g. Cooking reduces its volume by roughly half but preserves the calorie count. In Bulgarian cuisine it stars in баница със спанак.
How should I track Spinach?
Spinach is a good source of magnesium. For consistent tracking of Spinach, 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.