A substance, both a hormone and neurotransmitter, secreted by the adrenal medulla and the nerve endings of the sympathetic nervous system to cause vasoconstriction and increases in heart rate, blood pressure, and the sugar level of the blood. Also called levarterenol, noradrenalin. norepinephrine.
Foods that only contain protein, fat or both -- and are carb-free -- are few and far between. Most foods contain at least some carbohydrates. However, plant-based oils, other pure fats -- like butter and margarine -- meats, poultry, seafood and eggs are the best sources of carb-free foods.
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.