If I stop watering my kids, will they stop growing?

Yesterday at gallery walk David remarked that the stroller with the boys in it was awfully difficult to push. We joked to Seth, "You need to stop growing, you two are getting too big!". Seth replied, "Okay, I stopped."
Later that evening David was misting the garden in the backyard and the boys were running throught the water. It apparently was enourmously great fun since there was lots of laughter occurring. I stated to David, "If we water them, will that mean they will grow more?" We laughed.
Today I told Seth that he was getting taller and taller and getting to be such a big boy. He told me," That's because you water us, Mommy."
Makes sense to me. If only it was so easy, I could save a lot of money on my grocery bill.