Our bodies, having received these signals and determined this fruit is good to eat, now produce in anticipation precisely the enzymes and acids needed to break it down. Health depends heavily on knowing how to read these biological signals: This looks ripe; this smells spoiled; that’s one slick-looking cow. This is much easier to do when you have long experience of a food and much harder when a food has been expressly designed to deceive your senses with, say, artificial flavors or synthetic sweeteners. Foods that lie to our senses are one of the most challenging features of the Western diet.