What is the recommended minimum daily carbohydrate intake to meet brain glucose needs and prevent protein catabolism?

• A. 90 grams per day
• B. 130 grams per day
• C. 180 grams per day
• D. 220 grams per day

Answer: (B)

The main idea is that the brain relies on glucose for energy, and there’s a minimal amount of carbohydrate needed to meet that demand without triggering the body to break down its own protein to make glucose. Estimates show the brain uses about 120–130 grams of glucose each day in a typical adult. Providing at least this amount helps spare muscle protein from being broken down to supply glucose through gluconeogenesis. That’s why the recommended minimum is around 130 grams per day: it satisfies the brain’s glucose needs while minimizing protein breakdown elsewhere in the body. Consuming much more than this isn’t necessary for the question’s purpose, and lower amounts would increase the likelihood of protein being used for glucose.