I just published an article on my Substack about expectation-driven dopamine release and how it relates to Bright Line Eating, and I want to share the science behind this intriguing topic with you.
For years, I’ve had a question I couldn’t answer: Why doesn’t the sugar in colonoscopy prep trigger people with food addiction?
Some preparations contain an enormous amount of sugar; enough that I would expect it to light up a vulnerable brain. Yet after working with hundreds of people over the years, I never saw anyone get triggered by it.
I’ve always said that drugs hit us differently when we take them as medicine. Motives matter. Now neuroscience is giving us a better understanding of why.
Your Brain Responds to What It Expects
Research on expectation-driven dopamine shows that the brain can release dopamine simply because it expects a drug or reward, even before the substance itself arrives. A 2001 Science article gave people a placebo—but told them it would be a drug—and their brains released dopamine.
That helps explain experiences I’ve had in my own recovery. Years ago, during a relapse with food, I made raw cookie dough and poured a generous amount of vanilla extract into it. Afterwards, I realized how much alcohol the vanilla contained and even felt a little tipsy from it.
But I hadn’t intended to use alcohol. I had intended to use sugar, absolutely—but not alcohol. And instead of wanting more alcohol, I felt horrified that I’d consumed it.
I’ve experienced something similar with prescription opioids after surgeries. I take them as prescribed, minimally, for pain. And I’ve always been struck by how much I don’t enjoy them. Again, motives matter. My brain isn’t anticipating a drug experience; I’m taking medicine.
The Cues Can Start the Dopamine Before We Eat
Another piece of this is something called incentive salience. When the brain expects a reward, the cues leading up to it begin to take on enormous importance.
Picture me preparing that cookie dough. The bowl, the butter, the mixer—each one becomes a cue predicting the fix that’s coming. Dopamine is already rising before I’ve even eaten anything, and my attention starts narrowing around those cues. Other things, like my kids, my work, and the consequences, all fade into the background.
At the same time, the body begins preparing physically for what it expects. This is called the cephalic phase response. With drugs, the body may actually make compensating changes before the drug arrives, based on familiar cues and context.
This has huge consequences. One of the biggest causes of drug overdose is using a typical dose in an unfamiliar place. In that new context, the brain doesn’t get the familiar cephalic phase response cues and fails to brace for the incoming toxin. The result can literally cause death.
In other words, expectation is more than just a thought. The brain and the body are already responding to what they believe is about to happen.
When Even Weighed and Measured Food Starts Acting Like a Drug
This matters enormously in Bright Line Eating because a food doesn’t necessarily have to contain sugar or flour to start functioning like a drug in the brain.
Imagine a steak that is on your food plan. Maybe you have one particular marbled ribeye that you think about all week. You anticipate going to the restaurant for it on Friday night. You picture that steak. You can’t wait for it.
That food is lighting you up.
The cues, anticipation, and expectation may begin producing incentive-salience dopamine before you ever take a bite. And when your brain starts treating a food like a hit—something you intensely anticipate and organize your attention around—it can begin moving from the category of eating toward the category of using.
That’s why we sometimes talk about letting go, perhaps temporarily and perhaps longer-term, of foods that are technically Bright but are lighting you up.
Your expectation matters. Your intention matters. And paying attention to what your brain is anticipating can tell you something important about your relationship with a food.
