Tuesday, September 13, 2011

How to eat: hunger and its satisfaction

Hedonism Bot knows what hedonic circuits are
The concept of eating according to my desires and trusting my body to choose what I need, and only as much as I could use, was first introduced to me as a new parent. Folk wisdom derived from Ellyn Satter’s Division of Responsibility in Feeding came down to me as a method to feed small children. Based on this trust in the wisdom of the body, Satter encourages caregivers to provide regular meals including a variety of healthy foods, but not to worry about which foods the child eats or rejects.

Years later, on the Beyond Vegetarianism website, I read about Anapsology, or the Natural Hygiene movement. Like others in the ancestral health movement, these people attempt to mimic the prelapsarian conditions in which we thrived. “Instinctos,” as Anapsologists are also called, eat only one food at a time, in its unseasoned, uncooked state. They choose the food by following their desires, and eating attentively until they no longer want any more of the food. They describe the sensation of a food suddenly becoming less palatable as a “stop.”

The “stop” is also known as “satiation.” J. Stanton’s educational series on hunger and its satisfaction was a revelation for me, beginning with its vocabulary lesson in Part I. Not only were the subjective experiences of my body important and discoverable, but now I could talk about them with specificity. My hungers were not just my problem, or shameful. They were clues that I could use to satisfy my needs. Free-feeding from a healthy selection wasn’t just for small children: adults are also designed to eat according to their body’s cues.“Hunger is not a singular motivation: it is the interaction of several different clinically measurable, provably distinct mental and physical processes,” Stanton wrote, and I realized that I was learning the very basics of how I could feed myself competently.

Not only is there more than one hunger, the body has two separate systems, satiety and satiation, that tell you when to stop eating. One system, satiation, is a heuristic that estimates the nutrition you’re getting from the foods you’re eating, based on everything from what the food tastes like, what else you’ve been eating lately, and how much other people seem to be eating, to the comfort of your surroundings at mealtime. Satiation is meant to be a good predictor of satiety, which is the satisfaction of our nutritive needs.  Satiety is based on having digested the food, and knowing for certain what it contains. When we are sated, we have gotten enough energy, protein, fat, and other nutrients. We feel satisfied: replete.

The satiation system is accurate in a healthy person, offered a natural selection of foods, closely predicting the nutrition we will be able to get from the food we eat. Having a system that provides instant feedback at the moment we can use it is more useful than waiting the several hours it would take for satiety to occur. Satiation prevents us from chronically overeating until we feel sated. If we can't feel the "stop," we have to rely on other clues to tell us to stop eating, or eat until we are uncomfortably full.

The unhealthy effects of food deserts that limit our real or presumed choices, industrial foods that are designed to be highly palatable, large serving sizes that fool us into thinking this is what people typically eat at a sitting, and unexamined attitudes and beliefs about the relative value of different foods, all sabotage the hedonic circuits that translate food reward into future satiety. Our satiation systems, guessing at what will ultimately sate us, are led astray by hyper-rewarding food. When we eat quickly, eat foods that are bland, or drink high-calorie beverages, we take in the food too quickly even for our satiation signals to tell us to stop before we’ve had enough to sate. On the other hand, when we eat foods that simulate starch, fat, sugar, or salt, the satiation messages we receive do not match the foods’ abilities to sate. In either case, we may eat to satiation but not be sated, if our food doesn’t contain what we need.

Creating a lifestyle that supports healthy eating means correcting the environment, as much as possible, so we receive realistic messages about what we’re eating and can “hear” what our bodies want. The Instinctos do this by limiting their definition of food to what could be found and eaten in the wild, where we presumably thrived before civilization. Other traditional diets manage the environment by using the tools of civilization to regulate food supply and demand. Customs limiting the foods one may choose from, or the ways those foods are combined, or when they are eaten, are used to impose healthy limits. Satter’s program, as it is applied to adults, employs traditional methods like having regular meals and sharing them with others, as well as listening to the body’s cues for hungers and their satiation.

Being able to eat competently requires confidence that we know what is good to eat, that there is enough food, that it will be offered at frequent and predictable intervals, and that we can eat according to our pleasure and senses. An important step toward achieving this level of confidence is developing trust in our hunger drives, and being trustworthy in satisfying them.