Talmud says, "A full stomach leads to sin "

The Song of Moses goes on to portray Yeshurun, the upright one, as fat and slovenly—a reference to Israel's fallen moral state. The image is like that of a former Olympic athlete who has become rotund and lethargic.

The picture I see here is a fat spoiled rotten kid that is kicking and crying. He may have started out stamping his feet and screaming then falling on his tail kicking up a hissy fit as his face turns red with anger or frustration. We have all seen these kinds of kids and as one nursery attendant said, “It makes you want to volunteer for a drive by whuppin’!” 

God had provided so much for the nation Israel. Like a loving father, God guided them, gave them plenty of food, drink and land. God put them high on the earth and they lived high on the hog figuratively since they didn’t eat pork but they were very prosperous and safe. They were fat babies! They started out serving only God but that was to change.