White button mushroom has 32 kcal per 100 g. The classic supermarket mushroom. Slice raw into salads or cook — either way, the calorie impact is minimal.
About this food
How should I track Mushrooms, white button?
For consistent tracking of Mushrooms, white button, 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.