Brain energy allocation is consistent with adaptive thermogenesis.

Caloric restriction and weight loss reduce resting metabolic rate (RMR) beyond what is explained by the loss of fat-free mass, a phenomenon known as adaptive thermogenesis (ATRMR). Here, we frame ATRMR conceptually as the result of shifts in energy budgets within the body. Given the brain's central role as both a key regulator of energy intake and a major energy consumer within the body, we hypothesize that ATRMR represents one component of the weight-loss-associated reduction in energy expenditure and may reflect a redistribution of energy from the body to the brain, consistent with the hypothesis that adequate cerebral energy supply is preferentially maintained.