Oops, I did it again!

Imagine you are on a 1,500-calorie plan and your partner walks in with a box of warm cookies. You take one, then realize the number on your tally is already broken. Instead of stopping, you think “well, what’s the point now” and keep going with four more. Tomorrow you tell yourself you will start fresh.

That slip and the spiral that follows has an actual name. Psychologists call it the What-the-Hell Effect. As explained in The Willpower Instinct, once you break your own rule you feel guilty, and the quickest way to soothe the guilt is often to do more of the very thing that caused it.

This habit shows up in more than diets. It can push people back into smoking, heavy drinking, or hours of binge watching. The way to fight it is to plan for slip-ups before they happen. For example, deciding if you light one cigarette you will get rid of the rest of the pack. It also helps to step away from the guilt loop. Forgive yourself, remind yourself the setback is small, and give yourself credit for stopping it there.