I was familiar with general fasting already, but this book has introduced new insights I hadn't read about before. I'm not sure what the low reviews are about on here. One reviewer says she isn't a doctor. Apparently this person doesn't understand that 'doctor' refers to having a doctorate degree in any field. When it comes to healthcare, there are different practitioner degrees a person can have, whether that is medical doctorate, doctorate of chiropractor studies, doctorate of osteopathic medicine, doctorate of nursing, naturopathic doctorate, etc.
Medical doctors are not know-all gods of healthcare, which is why so many people give up on them after having no success with treating their issues. MDs have little training in nutritional studies and ecological physiology because they are trained to write prescriptions as primary treatments. Please learn the actual nature of healthcare studies and practices. A little critical thinking and self-education goes a long way.