Your body starts digesting food the moment you see it. Even when the food is plastic. Pavlov documented this over a century ago. The sight of a meal triggers saliva, gastric acid, and insulin before anything touches your tongue. Researchers call it the cephalic phase response, and insulin release shows up within about 2 minutes of the cue. A 2012 study in Obesity went further. People who simply looked at pictures of food showed measurably higher ghrelin, the hormone that makes you hungry, in…