Head, Desk, Addendum - Why do we get hungry?

An addendum to my previous post, which included my flip comment 'eet moar' if you're 'always hungry'. . .  Yeah, easy for me to say, right?  But we all know it's not always so black and white.  My last post touched on a couple of possible reasons Jeb Bush is 'always hungry' on a paleo diet; namely, those common and lingering entrenched conventional wisdom beliefs that to lose weight, your diet must be low-fat and low-calorie.  Of course, there's more to the story when it comes to why we get hungry. 

 

Thanks to the way-back machine, here is a post from Mark Sisson digging a little deeper into the idea of 'hunger'.  Hunger isn't simply a matter of  an empty tummy, but is influenced by the body's hormonal and biochemical processes over time, as well as the interplay of environmental and social cues.  I would like to highlight one point.  Quoting from Marks' post, "the overall nutrient-density of our diets appears to impact our experience of hunger. Study subjects who switched to a more nutrient dense diet reported feeling hungry less often, experiencing fewer and milder hunger symptoms and even sensing hunger from different locations in their bodies."  It's important to note that while the food we eat may be replete in calories, it may still be lacking in nutrients.  As Dr. Terry Wahls has noted, many people eating the Standard American Diet are starving themselves at the cellular level, regardless of the number of calories they consume.  This can lead to feelings of hunger, as the body signals that it need more nutrients, even if from a caloric standpoint one is 'over' eating .

For more about the role hormones play in hunger, PaleoMom has an excellent primer.  Whole9 has some additional information about the role of leptin and here is a more in depth exploration of leptin resistance from Dr. Loren Cordain's site.  That (previously) PaleoGuy has a good discussion on ghrelin.  Further zeroing in on the hormonal aspects of hunger, specifically as related to what happens when you have lost weight, a (relatively old)  article in the New England Journal of Medicine looks at the hormonal changes that occur in weight reduced subjects. 

 

The conventional wisdom weight loss bookend to calorie restriction (eat less) is exercise (move more).  Continuing to use Jeb Bush as an example, several articles mention that Bush swims religiously.  While exercise has many health benefits, it also stimulates the appetite.  An (old) article by Gary Taubes discusses some of the history behind the idea of  exercising for weight loss, and why exercise alone may not contribute to weight loss, but may instead make you more hungry.  From the article - "The feeling of hunger is the brain’s way of trying to satisfy the demands of the body. Just as sweating makes us thirsty, burning off calories makes us hungry."  Here, Dr. Peter Attia talks about how ". . . despite exercising 3-4 hours per day, I had morphed from a lean person into a sort of chubby guy over the preceding several years. . . I exercised more in one day than the average person did in one week. I didn’t eat at McDonalds or Taco Bell. I really cared about my health, but I was overweight. . ."  (Go here for a concise overview of how Dr. Attia lost weight.) 

For me, a deeper understanding of 'hunger' has allowed me to make more informed decisions about what I eat (sometimes 'eet moar' is appropriate, sometimes it's not), when I eat (sometimes going hungry is good, as in intermittent fasting) and how I exercise.  The more you know. . .