Dirty Secrets From Eating Clean: Food Addiction and the Leptin Connection

I wrote last time about how limiting calories can change the chemicals in your brain–how my dopamine highs from under-consuming calories and my endorphin highs from over-exercising had become inescapable addictions. But there is more to the story than  the upset of just a couple of brain chemicals:

We hear a lot these days about insulin, especially in reference to the diabestiy epidemic. [Brief science lesson: Insulin is a regulatory hormone that is secreted by the pancreas in response to the presence of sugar in the blood. Our bodies were only meant to have about 1 tsp of circulating blood sugar, so when you eat foods that contain (or are converted to) a lot of glucose, the body responds with insulin, which shuttles that glucose out of the blood and into your muscles to be burned or liver to be converted to glycogen and stored.]

But there’s another hormone that people are only just starting to talk about (because it’s only recently that science has begun to understand it…): Leptin.

Fat cells, believe it or not are part of the endocrine system (the system related to the release and regulation of hormones). Your fat cells tell your brain when you’re starving and need to eat or that you’re full and good to go by releasing the hormone called “leptin.” When your fat stores are high, your fat cells are full of leptin, which transmits the “we’re full, don’t send supplies” signal to the brain. When your fat stores are low, however, there’s a lot less leptin to go around, and your brain gets the message that you need to eat.*

Leptin is also responsible for stimulating the production of endorphins, the exercise-high neurotransmitter.

Now, there’s a lot of chatter in the science/nutrition world about leptin disregulation as a result of obesity, but what about leptin disregulation in anorectics and eating disordered people? (For a short, really informative look at how leptin disregulation and insulin resistance can influence/be influenced by obesity, check out this awesome video by Sean Croxton: Leptin: Fat-Loss for Smart People)

When you’re eating disordered, an overly restricted eat-clean devotee, or somehow reaching low levels of body fat, your leptin levels go way down. Your brain gets the message that you’re starving and need to build up your body fat levels again, so it tells your body to start craving food. The cravings raise your dopamine levels, making extended marathons of Man vs. Food seem like a good idea. Of course, the restriction is what feeds the dopamine high, so you keep restricting and craving.

Now, those of us who couple the restriction with exercise are in an even more dangerous boat, addiction-wise. Why? Well, as I mentioned earlier, leptin is partially responsible for your brain’s release of endorphins. If your leptin levels are low, your endorphins become low as a result. What raises endorphins? Exercise.

So it’s very possible that your exercise regime becomes necessary to maintaining your mental health. And, as with most addictions, you can easily build up a tolerance. Now you need more exercise to get the same high.

I know this to be true because I’ve lived it. Because I used to read the transformation stories on the Oxygen and Eat Clean websites, because I still follow some of the professional fitness models on Twitter. The stories are all the same: I was overweight (or thought I was) and decided I needed a change. So I started by cutting out processed foods. I felt so good that I went for a run. Then I found (insert clean-eating protocol here) and started lifting weights. I looked and felt so good that I got a personal trainer. In a few months, people in my gym suggested I compete. And so: the diet became a strict regimen of extra-lean meats and “complex carbs” like oatmeal and brown rice. And so: the exercise became fasted cardio in the morning and weights in the afternoon. And so: the complex carbs were “too much food” except around training times. And so: the exercise became necessary to not having a nervous breakdown today and I pushed myself so hard I cried but it was worth it because I’m still in shape. And so: the food became all I thought about and egg-whites-with-stevia are delicious, you just don’t understand because you’re not healthy and devoted like me. And so: exercise became the only thing I cared about, not that you’d understand because you’re busy living your fat lifestyle while I’m flying high on thinness and muscle.

It scares me that this is even a possible thought process, but there it is. (And you can find some version of it on every thinspiration Pinterest board or on some of the fitness pros’ Twitter feeds if you don’t believe me.)

I’m not saying that this will happen to everyone who tries to get healthy, nor am I against cleaning up your diet and starting to exercise–in fact, I’m all for it! But for those of us who may already suffer from neurotransmitter imbalances, trading one addiction for another–cookies and cake for quinoa and kale; “skinny is the new healthy” for “strong is the new skinny”–becomes a real and imminent threat.

And if you’ve ever had these thoughts, it’s okay: it’s not your fault. There are processes in your body and brain that you and I can’t see or hear or feel, processes that happen in the background, processes that can mean the difference between starvation and health, addiction and freedom. And once your body/brain chemistry is affected, it’s hard to see past the immediate need for the next hit.

It’s especially hard when the messages sent out by science and society only serve to encourage these addictions.

- K.

*Leptin isn’t the only hormone involved in hunger–there are other hormones/peptides like ghrelin and PYY that are secreted by the lining of your stomach/pancreas to mediate some of those hunger responses…But we won’t get into that today!) For more, check out Wellness Mama’s great explanation here.