It does seem to work for some people.  Maybe their childhood habits set a firm foundation for adult portion control and healthy preferences.  Maybe they have a different metabolic rate or biochemical reward system.  Maybe the ultimate insight about eating for nourishment and not for emotional reasons clicked for them, once and for all.  Some have never thought twice about eating as an issue, others have recovered from dysfunctional patterns and have even written books to guide others on the path.

I confess, however, that intuitive eating has not (yet) worked for me.  I have read the books and tried the exercises, but have never been able to maintain a healthy goal weight without conscious and sustained effort. Maybe it will click for me someday, but in the meantime I am not counting on it.

I was, therefore delighted to discover Gillian Riley's e-book, What Is Wrong With Intuitive Eating? (It's free if you subscribe to her monthly updates.)

In this quick read, Riley outlines the biological and psychological reasons for our tendency to consume more than we need to maintain a desired weight. Her longer books, Ditching Diets and Eating Less go into greater detail. (See "From the Bookshelf" below.)  

A recurring theme for Riley is the unreliable relationship between hunger and nutritional need.  We are not precision instruments for which hunger is a sign of genuine deficit in the moment. Nor do we have a fine-tuned internal meter that tells us when enough is indeed enough. Hunger is more likely to be a response to cues, such as the sight of food; or a function of habitual patterns, such as eating at noon. We often experience "full" only when we are on the brink of overflowing, and we may be even hungrier at the end of a meal than we were before we started.

In addition to the imprecise and misleading thresholds of hungry and full, we are influenced by the addictive makeup of the brain.  Certain "feel-good" neurochemicals reward a wide variety of behaviors, from eating to alcohol and drug use, exercise to gambling, shopping to sex. Addictive eating is driven by the urge to release those pleasure-generating substances, not by the body's realistic assessment of deficiency. 

Various theories cast light on the adaptive value of addictive eating over the millennia. According to one theory, our ancestors never developed an instinct for moderate eating.  Their food supplies were uncertain, and times of scarcity could be long and severe.  People who survived, reproduced, and passed along their genetic programming binged when the eating was good, buffering themselves against lean times to come. 

Another theory notes that the fats, sweets, and starchy foods needed for brain function were often in short supply.  Early humans therefore overdosed on those food groups whenever they could.  Like Montana grizzly bears up to their armpits in huckleberries, moth larvae, and pine nuts; they packed it away without counting calories or limiting grams of sugar per serving

Yes, we are part of nature.  Our brains and behaviors as a species have developed under conditions very different from those we face today. The year-round overabundance of food, prevalence of advertising and processed foods scientifically designed to trigger the binge reflex, sedentary lifestyles resulting from increased mechanization, and increasing prevalence of overweight-associated disease are signs of recent change.  Understanding, insight, and sustained effort can enable us to develop skills for navigating our complex environment. "Intuition" is not, for many of us, enough.