3 ms·

It seems to be metabolized (into glucose?) much more evenly than carbs.

• dredmorbius 15y ago
  No, lipids are metabolized directly as lipids (via lipolysis). In the absence of sufficient dietary carbohydrate, some lipids may be transformed into ketone bodies via a process called ketosis, to provide an alternate fuel for the brain. This is what the Atkins and other very low carbohydrate (<~50-100g/day) diets seek to accomplish. Dietary carbohydrate (other than fructose) is directly metabolized by cells as glycogen. Two tissue types (brain and red blood cell) prefer glycogen, red blood cells require it. Your body can store about 200g of glycogen split between the liver (~100g) and skeletal muscle. Liver reserves can fuel any body function, muscle stores fuel just that muscle. Excess carbs are converted (by the liver) into fats, and stored as same via the insulin/glucagon endocrine balance. Look up the Krebs Cycle for more information. Dietary fats serve as long-term, low-rate fuel for skeletal muscle and organs (other than the brain and red blood cells), and is either metabolized directly or stored as adipose tissue. Dietary protein isn't metabolized directly. It's used for structural processes as its component amino acids, some of which can be synthesized by the body, but some (essential amino acids) cannot be, others are rate-limited to a degree that dietary supplementation is occasionally recommended. Protein (dietary or from body tissues) can be converted to glycogen through a process called gluconeogenesis. This occurs both in low-carb diets and during starvation.