He might be playing too hard after eating but he also might be intolerant of the food you are feeding. Often cats throw up right after eating if the food has an ingredient that bothers them.
While mostly food allergies make animals itch sometimes they can cause vomiting.
You may want to look at what you are feeding and compare it to the higher quality cat foods from a pet supply store for ingredients.
You can look at food ingredients here
http://www.naturapet.com/display.php?d=comp-wiz&animal=Cat
check some of the premium foods like Wellness, Felidae, California natural cat, Chicken soup for the cat lover and others.
Hope this helps you!
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