I don’t have any experience with fasting while on medical like that, but as someone who has to take meds like that, I’ve only ever done kind of a lazy omad diet. I eat a small something with morning dose so they don’t tear a hole in my stomach lining, so something like a boiled egg and a yogurt. And then I do a full meal with my evening dose. I’ve lost 45lbs in 6 months. So nothing as extravagant as an actual fast would be, but it’s helped my self esteem none the less.