Published: 01/05/2022

What is the definition of a low-carbohydrate diet?

“Low carbohydrate” is not defined by the U.S. Food and Drug Administration, and the definition of a low-carbohydrate diet varies in the literature. However, most experts in the field agree that a low-carbohydrate diet should be limited to a maximum of 130-150 g/day (1), and many experts consider the cut-off of 130 grams/day as it is below the Adequate Intake set by the IOM. In fact, a strong body of research shows limiting intake to no more than 130 grams/day, or less than ~25% of total daily calories, promotes a variety of positive metabolic outcomes (2-3).

An amount of less than 50 g of carbohydrate per day is considered very low carbohydrate, which would put most adults into nutritional ketosis (4). During this state, the body relies primarily on fatty acids and ketone bodies produced from fat stores, not glucose, for energy.