On the way to a friend’s house, I went to a drive-through and ordered a burger and a shake. I still had the several-day-old remainder of a beverage in the cupholder that I needed to dispose of, but there was a waste can just beyond the pickup window, so after I got my order I pulled forward and used it.
After I ate my burger, I reached for milkshake, and discovered that I still had the old beverage, and had thrown the shake away.
That did save me 660 calories. Maybe I should have bought three shakes and thrown all three away, and I could have saved nearly 2000 calories!