"You" don't take antacid after eating unless "you" have problems with your stomach acid or something. Neutralizing your stomach acid isn't generally a smart thing to do, because it's acidic for a reason (digesting food). Some people even recommend not drinking to much water with your meals because it dilutes your stomach acid, though that might be overly cautious. Whether adding baking soda to food makes you feel fuller I wouldn't know, but it certainly won't make you "feel better", unless you have some medical condition.