Part of the explanation is the longer time it takes to digest protein and its ability to keep your blood sugar level steady. This, in turn, prevents the kind of cravings that seem to kick in soon after you finish, say, a jelly doughnut.
Recent research done at the University of Warwick in the United Kingdom has found that there's even more to this than we thought. Apart from your digestive system, the brain is also a key player in why protein is so satisfying. Receptors in the area of your brain that controls weight quickly respond to the amino acids in certain high-protein foods and send out the message that your hunger has been satisfied.
It's all part of a chain reaction that starts when certain taste buds are activated by protein's savory flavor, often referred to as umami - the so-called fifth taste after salty, sour, sweet and bitter. Two amino acids in particular elicit the fast response - arginine, which is not one of the nine essential amino acids, and lysine, which is one because your body can't make it on its own.
We've long heard that it takes 20 minutes from the time you start eating to get the message that you're full, but almost from the moment you take your first protein bite, the brain cells in question, called tanycytes, start to react.
And turkey's not your only choice. According to the U.S. Department of Agriculture, foods with the highest amounts of both arginine and lysine include many cuts of beef, chicken, fish, pork loin, edamame, beans and lentils.