Question about Finally Take Control of Your Weight

I have questions about the “Joy Eat.” Is it supposed to be used as positive reinforcement? i.e. If I follow the plan that I set for myself, I get to indulge in a “joy eat” – let’s say once per week? What if I overindulge or “fall off the wagon” before the scheduled “joy eat,” do I still indulge in the “joy eat”?