The present invention addresses the problem of providing a technology for long-term retention of the total ketone concentration in the brain. The present invention provides an agent for raising the total ketone concentration, the agent comprising 30 to 75 mass% of C8 medium-chain fatty acids, 0 mass% or more but less than 25 mass% of C10 medium-chain fatty acids, and 25 to 60 mass% of C12 medium-chain fatty acids with respect to the total amount of medium-chain fatty acids. Moreover, the present invention provides an oil and fat composition containing an oil and fat having structural fatty acids comprising 50 to 75 mass% of C8 medium-chain fatty acids, 0 to 10 mass% of C10 medium-chain fatty acids, and 25 to 50 mass% of C12 medium-chain fatty acids with respect to the total amount of medium-chain fatty acids.
