Adaptation in Low Energy Availability

During periods of low energy availability, the brain's metabolic rate does not necessarily decline significantly, challenging previous assumptions. Research has not conclusively shown that cognitive function deteriorates during fat loss phases, even extreme ones, as seen in prolonged fasting cases. Individuals display adaptive responses to energy deficits that vary based on the magnitude of the deficit and genetic factors. Larger energy deficits typically lead to more pronounced adaptations, which can include reduced overall energy expenditure and decreased spontaneous movements. Changes can also occur in metabolic processes related to food intake and digestion, alongside potential reductions in resting metabolic rate.