We all know that there’s a rational part of ourselves and another part that’s got its own silly, and sometimes harmful, ideas. These aspects of self often battle with each other over food and other decisions: rationality asserts one thing while irrationality says quite another. This is a natural and inevitable process that we go through in making choices. What determines health over lack of it is which thought we let win each skirmish.

Clients often confess that they did think about stopping eating when full, going to the gym, saying no to an unreasonable demand, standing up for themselves when they’ve been hurt, etc., but then this “little voice” told them to finish what’s on their plate, let the gym slide for another day, cave to the demand, or remain silent to avoid an argument. If we think of the first voice as the rational one and the second as the irrational one, you can see how letting the irrational voice have its way with you only gives it more power.

Which leads me to my point: When these two parts of you are duking it out, you have to make sure that rational thinking gets the last word. Rationality come from the frontal lobes of your brain, what’s called the executive function, which processes life through reason. Irrationality comes from your limbic system or emotional brain, which consists of your fears and magical thoughts. Who do you want running your life? I know who I want running mine! This doesn’t mean you can never let your emotions run free or guide your life. It does mean that you have to know when that is appropriate and when it isn’t.

If you think of your irrational self as the child in you and the rational self as the adult, you’ll get a clearer picture of this process. If a child goes to run out in the middle of traffic, eat dirt or refuses to take a shower, you don’t let her. The adult overrules the child because the adult knows better. The adult says, “Wait for the light,” “You can’t eat dirt because you’ll get sick,” and “You need to shower to be clean.” Rationality wouldn’t dream of letting a child have the final say on matters like this. It exerts itself forcefully because it is in charge and takes that responsibility very seriously.

So, when you’re making food, scale, or exercise decisions, make sure that the rational side of you has the last word, the final say, every time. It’s not enough to struggle back and forth with irrationality if you’re going to cave and let it win. The point of the struggle is to override it and come out on the winning, rational, sane side. If you want to act rationally, you have to teach yourself to think rationally about what’s in your long-term best interest. When it comes to eating and life, rationality rules!