Why is crunchy food so appealing? Why is it so hard to find names for flavors and smells? Why doesn’t the stomach digest itself? How much can you eat before your stomach bursts? Can constipation kill you? Did it kill Elvis? We meet scientists who tackle the questions no one else thinks—or has the courage—to ask. And we go on location to a pet-food taste-test lab, a bacteria transplant, and into a live stomach to observe the fate of a meal.