There is a false myth that humans have to eat carbs because the body can't make them (whereas it can make protein and fat). In fact, the body can make carbs, the process is called gluconeogenesis.
gluco = sugar
neo = new
genesis = creation
= creating new sugar
How? The body makes sugar out of several amino acids, a key one being glycine. Common high glycine foods include meats, the highest being chicken breast.
Gluconeogenesis the best way to get carbs (though you still usually need other sources in addition) because all the carbs will get used properly and none will be wasted. Gluconeogenesis produces just the right amount of carbs that go to muscle glycogen and/or blood sugar but will not make excess carbs that turn to fat. Now that's efficient.
If you think about it, carnivorous animals have to be able to make their own carbs because carbs are necessary to feed fast-twitch muscles which only run on sugar. Cats, for examples, are carnivores and obviously have fast-twitch muscles to pounce.
Key points:
-your body will make sugar through gluconeogenesis from your muscle if you don't eat protein and have low blood sugar. That's why people who go on low-carb diets without enough protein lose their muscle mass and become skeletons.
-gluconeogenesis doesn't work when you eat fructose.-gluconeogenesis is really useful for diabetics -- you can have your carbs but can't have high blood due to gluconegogenesis
