An especially cruel part of Nature’s Grand Design is that just at the point when a young man, say one of 16 (our son), is amping up his eating, everyone around him (his sister, his parents) are shutting theirs down.

Matt, a cross country and track runner, is joyously eating ALL the time these days.

“You might as well buy a box of cereal a day, Mom, because I can finish one all by myself. EVERY day,” he recently said.

I laughed. And then I watched.

He’s right. I’d heard about this phase with competitive swimmers and other high-energy-consumption athletes.

It is ironic that Mother Nature has him piling it in and piling it on right at the point where the rest of us are always walking it off.

Our daughter, soon 24, was looking wistfully at her brother one day, eating anything he wanted, and said, “Enjoy it now because it doesn’t last!”

Anne, a competitive swimmer and cross country runner, herself, through high school remembers the days when everything she put in her mouth was instantly burned off by exercise or growth. Or both.

What was once so easy soon takes some toil (or you trick yourself into thinking “toil” is really “fun”).

Sometimes Nature can be oh so cruel.