yeah, i can't see every 30 mins being very convenient at all.
plus if you don't eat enough, you get not enough insulin released, etc.
think of it like this: 20,000 years ago, humans were nomadic tribesman who were hunter/gatherers. Walk a few hours...then stop for 10 mins to rest, drink water, eat some berries and snack on dried meat. repeat 5 times a day, then setup camp for the night.
we really haven't evolved that much in 20,000 years...our bodies still like frequent 'grazings' of nutritious foods.