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.
Carbohydrates are an essential nutrient for your body. During digestion, they break down into glucose, or blood sugar, which is the primary source of fuel for all cells. Nearly all of the foods you eat contain carbohydrates. Meat, eggs and some types of seafood are the only foods that do not have carbs.