Don't many animals sleep after eating? I know my dog and cats do...

Also, the parasympathetic nervous system (homeostasis and rejuvenation) kicks in when you're relaxed (including sleeping) and it facilitates digestion. The sympathetic nervous system (fight or flight) impedes digestion. This is why eating before exercise is contraindicated, while eating before a massage is healthy. Many of my clients stomach's start grumbling during a massage ... a sign of relaxation and ideal digestion conditions. Wouldn't sleep be similar?