what has protein but no carbs
There aren't any natural foods that have no carbs and no fat. All meats have some fat. Egg whites are the closest. They have no fat, almost no carbs, and plenty of protein. Don't include the yolks. They have lots of fat and some carbs. There are some processed foods, like protein isolates (whey protein isolate being the most common) that have no carbs or fat. There are also diet drinks.