Instruct: Classify an Amazon review as either positive or negative.
Query: questionable claims should be a red flag to readers

This book is well written as a quick read. However, I disagree (and believe archaeleogical studies will back me up) that primitive man (type O) was primarily a meat eater. Humans were gatherers before they were hunters and hunting only supplemented the gatherers, and eventual farmers. Therefore, the diet emphasis of high protein for type O's just doesn't hold water. Because of this discrepancy I question everything else in the book.