What is the "body budget" metaphor?

The "body budget" metaphor, as explained by Dr. Lisa Feldman Barrett during her appearance on the Huberman Lab, is a way to conceptualize how the brain manages the body's resources. The brain, acting like a budgeting manager, tracks and allocates resources such as glucose, salt, oxygen, and water, which are necessary for maintaining life and optimal function. This metaphorical budget covers all the physiological expenses that keep us alive and well.

Just like any budget, there can be deposits, such as eating and sleeping, which replenish our resources. Conversely, there are withdrawals, such as physical activity or stress, which deplete these resources. For example, social stress can increase the metabolic cost of a meal, much like additional caloric intake, due to inefficiencies caused by stress.

Barrett further explains how the body's metaphorical financial state, being in surplus or deficit, affects our affective state (feelings of general well-being or distress) which can be thought of as a quick summary of how well our "body budget" is balanced. This interpretation extends to mood disorders like depression, likening severe cases to a kind of metabolic bankruptcy where the body lacks the energy to function properly. This metaphor helps in understanding why certain conditions or behaviors emerge based on our body's perceived resource state 1 2.