Hungry Kids are Crabby Kids

I've learned that hunger can cause grumpiness. My children's grump factor increases exponentially when they are hungry. Today we stopped for contact supplies after Bible Study, and my children, who are usually fairly well-behaved, were completely unhinged. They fought over who got to put the items where in the cart and on the checkout counter. I brought them home and I thought WWIII was going to break out over the colors. I put the maccaroni and cheese in front of them and after lunch they were the sweetest children. I should know this already; my husband gets grumpy when he is hungry as well.