Bipolar Disorder, Type 1

The goal of this clinical trial is to test how specific components of diet affect brain function and behavior for individuals with bipolar. The main question it aims to answer is how glucose and ketones each affect the brain's response to risk and reward. Participants will be asked to provide blood (to assess baseline measures of how the body uses energy), and then to receive two MRI scan sessions, on separate days. During each MRI scan session, participants will play three games, from which they can win money, before and after drinking glucose (on one day) or ketones (on the other day). Investigators will compare individuals with and without bipolar to test whether the two groups differ in how their brains use energy, and to test how the brain's use of energy affects behavior.