Choice of Apples

Choosing to Eat and Breathe and Control Your Weight

Choosing is something that people hold dear. Even if we’re not always good at it. So, quite naturally, when people assume that obesity is all about food (not exactly true), they assume that the answer is better food choices. But a new review from Trends in Cognitive Sciences gives us reason to pause and think.

Food choices can be as much a result of obesity as they are a cause.

The Brain’s Prefrontal Cortex

Cassandra Lowe, Amy Reichelt, and Peter Hall present a very thoughtful review of how the brain’s prefrontal cortex functions in obesity. This is the part of the brain that’s critical for choosing – what to eat, what to do, how to respond in any number of situations.

The authors review a great deal of neuroscience that explains how obesity can affect this part of the brain. The result is subtle but important changes in cognitive function. Those changes can lead to more obesity. But in addition, biological differences in this part of the brain can add to the risk of obesity developing in the first place. Lowe explains:

It’s not just the case that obesity is causing these issues in the brain structure and function, but it is this reciprocal relationship. Differences in brain structure and function can cause obesity. That’s really important. Our review shows that if you have lower prefrontal activity, it can predispose you to overeating, which in turn can lead to weight gain and obesity.

Beyond Conscious Thought

At this point, we must step back though. This review is extremely focused on conscious thought and choosing what we eat. As Obesity Society President-Elect Lee Kaplan explained to us recently, this misses a bigger question. How does the long-term regulation of body weight go awry in obesity?

The answer to this question does not lie solely in the brain’s prefrontal cortex. It’s not all about food choices. To get to a more complete answer, we need to understand how the hypothalamus regulates metabolism and fat mass. Reward systems play a role, along with executive function, but some of the most critical pathways go through the hypothalamus. Boston University’s Caroline Apovian tells us that the key questions are about homeostasis:

We need to understand how the reward system can create havoc and then cause permanent changes in the homeostatic center in the hypothalamus

Understanding Obesity: Beyond Food Choices

As much as we like to celebrate the power of healthy choices, they are only one input into how our marvelous bodies function. We don’t choose how much to breathe, even though we can choose to hold our breath for a moment. We certainly can choose what to have for breakfast today. But we don’t choose how much energy to store as fat.

Our hypothalamus does a fine job of that. But in obesity, this process goes awry.

Click here for the review by Lowe et al and here for more on that review. For a broader perspective on the obesity neuroscience, we recommend reviews here, here, and here.

Choice of Apples, photograph © Capt Coffee/ flickr

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February 28, 2019

One Response to “Choosing to Eat and Breathe and Control Your Weight”

  1. March 01, 2019 at 2:43 pm, John DiTraglia said:

    The complicating problem whenever you try to say that people with obesity think or act or eat differently is the set point. People with obesity are constantly pushing off their set points which is different than being off their rockers. At set point everybody is pretty much the same on average…