Researchers have identified three distinct neural pathways that control our desire to eat. Two rely on our desire to avoid discomfort. The third is all about pleasure. Understanding these three neurological triggers may help tame an out of control appetite.
If you’re trying to manage your weight, chances are that you have spent a fair amount of time thinking about hunger. How can you eat less without feeling hungry? Is there any way to control your appetite? How do people who weigh less do it? Do they simply not experience hunger? Are they hungry all the time? How can you distinguish between true hunger and the urge to eat?
As someone who coaches people on sustainable weight loss, these are questions I’ve spent a lot of time thinking (and writing) about, as well. Today I want to tell you about the three different ways our bodies register or experience hunger.
In my recent episode on how calories in food are determined, I talked about the hazards of relying too heavily on calorie counters and calculators. I pointed out that we probably can’t rely entirely on our hunger or satiety signals to tell us if we need food and when we’ve had enough.
And I bet that might might have been what triggered a listener to phone in and ask what I thought of intuitive eating and whether there was any good research to support it.
Does Intuitive Eating Work?
Intuitive eating is a popular concept these days and people throw this term around pretty loosely. It’s hard to know sometimes exactly what they mean by it.
For some, it just means not following rigid diet rules. I’m all for that! But if you’re having trouble managing your weight, that approach alone may not be enough to solve the problem. I talked more about the strengths and weaknesses of intuitive eating as an approach to weight management in episode #397.
On a closely related topic, Cheryl from Massachussetts emailed this week to ask:
“Even when I eat a good sized meal with adequate levels of protein, fat, and fiber, I can feel hunger after just an hour or two. And sometimes when I'm experiencing digestive upset, it feels like hunger. Do other people have a hard time distinguishing between digestive activity and hunger pains?”
You bet they do, Cheryl! In addition to all the environmental, emotional, and social cues that can fake us out, there are a number of digestive disorders, everything from acid indigestion to IBS, that can cause false hunger or, conversely, mask hunger symptoms.
I have more tips on how to tell if you’re really hungry in episode #387.
Which brings me to some fascinating research that my sister (who is a neurobiologist) recently forwarded to me.
The Three Pillars of Appetite
Researchers Scott Sternson and Anne-Kathrin Eiselt of the Howard Hughes Medical Institute in Chevy Chase, Maryland, recently published a paper in the Annual Review of Physiology titled "Three Pillars for the Neural Control of Appetite."
Sternson and Eiselt describe three neurological mechanisms that control appetite. The first is triggered by low blood sugar. When our blood sugar levels get low, we start to experience unpleasant sensations which increase in intensity until we get something to eat. (Interestingly, these unpleasant sensations to start to diminish as soon as we have access to food...even before we’ve consumed it.)
The second neural pathway is triggered by the proprioceptors in our stomachs that tell us that our stomach is full. As our stomach stretches, we feel less comfortable, which decreases our desire to eat.
The third appetite control mechanism is triggered by our senses. The sight, smell, and taste of palatable foods arouses pleasurable sensations that entice us to eat.
We’ve talked about all of these concepts here on the Nutrition Diva podcast before. But Sternson and Eiselt have shown that these three mechanisms are governed by completely different neural pathways. They are, to some extent, redundant systems. Here’s anther thing I found really interesting about their work...