When I introduced the notion of following a food plan inflexibly to Robert, he initially experienced both anxiety and skepticism. Robert asked me why he couldn’t just make substitutions when he felt like it as long as the calorie count remained the same. Here’s what I told Robert:

It’s essential for you, and all dieters, to learn the skill of inflexible eating before you move on to flexible eating. By inflexible, I mean making a plan ahead of time (either the night before or that morning) for the coming day, and learning how to stick to it exactly, with no substitutions. Once you can do this, you’re ready to start flexible eating—making a plan and then sticking to it but making substitutions if/when you want to. And to start to calm your [very normal and expected!!] fears, I can tell you that really learning inflexible eating is one of your best insurance policies against regaining weight down the line.  Once you become really get good at this (and of course it will take practice, but the more you practice the better and better you’ll become), you won’t have to worry about regaining weight. If five, ten, or fifteen years from now you begin to see the scale creep up, all you’ll have to do is return to making your food plans ahead of time and sticking to them, and your weight should begin to drop. It’s SO important to learn this skill now—so that you can use it in the future and for the rest of your life.

Hearing this, Robert understood why it is important for him to learn the skill of inflexible eating. He was still nervous about trying and failing, but I told him that every one makes mistakes when learning new skills; it’s what makes us human!  I expect Robert to make mistakes, but as long as he learns from his mistakes and keeps trying, he will eventually become good at this.