Dear @leonk,
Long term starvation over weeks is very stressful on the body and can lead to bad health outcomes.
Fasting has been mentioned in other threads:
- Lifestyle changes, nutrition, and supplements for hep b - #90 by ThomasTu
- cccDNA and virus reactivation - #29 by availlant
And there are resources on other site about this: Is Fasting Safe for People Living with Hepatitis B? - Hepatitis B Foundation
Scientific studies haven’t shown any effect of fasting on HBV (at least in mice): Limited Effects of Fasting on Hepatitis B Virus (HBV) Biosynthesis in HBV Transgenic Mice - PMC
So I think you need to be careful about this and talk it through with your doctor.
Thomas