During digestion blood is directed away from the muscles and tissues and toward the digestive system. If you were physically active before eating your meal, which generates heat, and then stopped and ate, the combination of heat lost due to digestion and the loss of blood flow to the skin may cause you to feel cold.
View by Expert John Reas-
Because our bodies concentrate energy into digesting the food we just ate. This diverts a fairly large amount of blood to various internal organs to facilitate this process efficiently. Because of this, there is less blood in the vessels nearest to the surface of your skin, causing you to feel rather cold after you eat. Strangely, this ALWAYS happens to me when I eat at Panera Bread for some reason, although it happens occasionally elsewhere as well.
Edit: apparently this doesn't happen to everyone and could be an indicator of a mild form of Raynaud's Syndrome which you may want to research a bit and see if you show other symptoms like hands and feet that frequently fall asleep and/or get white splotches on the skin.
