If you think you might want to know why Arctic nomads eat organ meats and why they can be classified as both "meat" and "fruit and vegetables" , or that aroma and taste matter in a ratio of 50/50 to cats but 70/30 to dogs, you might want to go to the library and check out Gulp by Mary Roach.
Only 2 chapters in, I am finding it quite interesting, and I haven't even gotten to the chapter on flatus (gas) yet, or the one about how to survive being swallowed alive. I am not even kidding one bit about this. Mary Roach is a great science writer. Her approach is to take an ordinary topic and tell us the answers to the questions we have always wondered about but didn't know who to ask. In Gulp she covers the digestive tract. From beginning to end.
The plan was to wait until I was completely finished to tell you about this book but I couldn't. Perfect weekend reading. Packed with tons of well researched interesting tid-bits the person you live with is going to want to know too.