The final acceptor of electrons in the electron transport chain is molecular oxygen. Electron transport chains are used for extracting energy via redox reactions from sunlight in photosynthesis or, such as in the case of the oxidation of sugars, cellular respiration.
On their website, the American Diabetes Association directs diabetics to eat between 45-60 grams of carbohydrates at each meal. Assuming a person eats three meals a day, this advice works out to telling diabetics to eat a minimum of 135 grams to a maximum of 180 grams of carbohydrates per day.
Low-carb diets allow you to have somewhere around 50 to 150 grams of carbohydrates each day, MayoClinic.com reports. Since carbohydrates offer 4 calories per gram, this amounts to a minimal 200 to 600 calories from carbohydrates. Some plans make you go as low as 20 grams per day, or 80 calories from carbs, which is far less than the recommendation.