Similarly, blood pressure is often markedly reduced in just the first few days of fasting, requiring similar prompt medication adjustments down and then back up. (blog.virtahealth.com)
For example, during the first days of fasting, insulin concentrations slightly decrease, encouraging a switch from our body using glucose to using fat as a main source of energy. (bembu.com)
After 2 full days of fast and furious eating and drinking we were spent. (melanieknopke.com)