Saturday, March 16, 2013

The Nutrition Debate # 92: Why We Eat

Why do we eat?  Of course, the simple answer is, “We eat because we’re hungry,” but this begs the follow-up question, “Why are we hungry?” It also requires a few footnotes for the obvious exceptions. For example, there are occasions when we eat when we are not hungry, and when we overeat when we are. So, I don’t purport to have all the answers or even to fully explain the ones that I do. I just want to lay out a basic outline of the issues as I understand them because I think it is useful to think about the question. We should examine the way we have come by habit, tradition and culture to live and eat the way we do. And then, to separate those from why we need to eat.

Eating, I noted from watching a Stephan Guyenet “Ancestral Nutrition and Health” video on his Whole Health Source website, can be divided into homeostatic and non-homeostatic categories. Homeostatic eating is for hunger only, Guyenet explains, whereas non-homeostatic is all other eating, including eating for pleasure, emotion/stress, social, and ‘mealtime’ eating. Whole books have been written about each of these examples of non-homeostatic eating, and I think most of us can readily relate to each, if not to all of them. This, then, is but a cursory review.

What characterizes each of these non-homeostatic categories is that none of them is driven by hunger. Eating for pleasure is an indulgence, a pure luxury. Eating to relieve stress is an outlet – a diversion, but it is not driven by hunger. Social eating, as in hor d’oeuvres at cocktails or before a dinner party, is a custom of hosting and accepting the hospitality of a host. This is also a way to allay anxiety much in the way that smoking was and drinking is in such situations. And eating three meals a day at prescribed times regardless of whether or not we are hungry is a vestigial tradition from a time when most of us lived a life of heavier exertions. Many cultures today still have their main meal (dinner) at mid-day, and a light supper at the end of the workday. These practices, including eating “regular” meals at fixed times, are all examples of non-homeostatic eating. It’s worth thinking about that last point, if you’re not hungry.

Eating more than is required to satisfy hunger is a little more complicated and is in a different category that needs to be addressed separately. I like the way Guyenet frames the issue: “What makes us eat more than is required for leanness?” he asks.” Leanness!  Hmmm…. A tantalizingly appealing question; it makes me want to know the answer. Guyenet’s answer is “…the system that regulates long-term energy balance and body-fat mass. Okay, this is where we get into “the weeds” – human physiology and biochemistry – neither of which is my strong suit. So, I’ll leave you on your own to explore all the experts who delve into this subject every day on the web. My personal favorite, perhaps because his views informed mine, is Gary Taubes of “Good Calories-Bad Calories.” He is at odds, though, with Stephan Guyenet.

So, I have framed the question. Now I want to return to what we can do to understand our current situation and our options. We must separate out all the occasions of non-homeostatic eating. We must think of all such occasions as voluntary excursions apart from homeostatic eating. They do not impel us to eat (unless we’re carb addicted sugar-burners  needing a “fix” every couple of hours). They are not “what make us eat more than is required for leanness.” It is a choice we make and as such it is entirely within our control. We (theoretically, at least) can do it or not, as we decide.

Then, with only homeostatic eating “on the plate,” as it were, can we understand what “regulates long-term energy balance and body-fat mass”? From my perspective the world is divided into two cohorts: those with normal fat metabolism and those who have developed a disregulated fat metabolism. It is well beyond the purview of this short article to discuss the susceptible genotypes of the latter group, but suffice it to say that almost everyone who is overweight or obese, and who otherwise has the symptoms of Metabolic Syndrome, falls into the “disregulated” group.

For this group, the regulator of long-term energy balance is insulin. Those who fall into the disregulated group have become insulin resistant. In other words, their cells are resistant to insulin, so insulin levels rise in the blood. This blocks access to fat stores so they crave “sugar” (carbs) for energy. The higher levels of circulating insulin prevent the body from accessing the fat stores that we have set aside to be used for energy.

Such is the situation. So, what is the solution? How can anyone who is overweight or obese, and especially those who have Metabolic Syndrome or are pre-diabetic or are diagnosed with Type 2 diabetes, get access to their own body fat stores for use as energy when the body is in need of it for “long-term energy balance”? The answer: Eat a Very Low Carb diet. Eat a diet very high in fat (mostly saturated and monounsaturated), moderate protein, and VERY low carb. When you eat Very Low Carb, your serum insulin drops and fat stores break down and enter the bloodstream to supply energy.
“Not eating more than is required for leanness” is a process. Being lean is a “product.” It may be merely a “pipe dream”, but the only way to find out is by the process. The VLC Way of Eating is easy, once you get used to it. The “product”???

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