Therapeutic Ketogenic Diet in Partial Hospital Program (PHP) Anorexia Nervosa

This will be a 14-week longitudinal study with an open design. A total of 120 individuals will be recruited for an end goal of 60 individuals with anorexia nervosa (AN) who are currently in high level of care treatment at the UCSD Eating Disorder Center partial hospital program (PHP) or intensive outpatient (IOP). Forty individuals will be recruited to the TKD and 20 will be treated with treatment as usual with respect to food intake. The age range will be between 16 and 45 years. All study participants will be carefully assessed and will complete rater and self-assessments at the being at the end of the study period. While in the treatment program, the TKD group will receive catered ketogenic meals via a meal service. After discharging from program, participants will have the option to continue with the meal service or cook for themselves. After establishing ketosis, study participants will continue TKD for 12 weeks. All study participants will be followed over three, six, and twelve months after enrolling in the study, whether initiating TKD or being in the treatment as usual arm. This follow-up procedure will help determine whether symptom improvement is stable or worsens in individuals who choose to continue or discontinue the TKD intervention and in relation to the control group. After ketosis induction over two weeks, study participants will be assessed weekly for ketosis and mood, anxiety, and eating disorder symptoms over twelve weeks.