Appetite alert: Should you trust your tummy instead of counting calories? We explore a better way to heed your hunger signals

Muscle & Fitness/Hers, Feb-March, 2002 by Beth Sonnenburg

The basic process of hunger can be likened to a traffic light: Green means start eating, yellow cautions that you're nearing the Fullness point, and red means stop.

Our physiology is actually designed to give us the green, yellow or red light, which could theoretically end the whole calorie-counting business in Favor of simply eating according to physical hunger and Fullness. Unfortunately, the practice isn't that simple. For one thing, distractions get in the way of physical sensations. Though our body says "green light," we might be stuck in a meeting or an hour away from dinner. And the red lights? We often run those altogether, eating way beyond the point of fullness or munching when we aren't really hungry.

Would we be better off obeying physical signals rather than continually overriding them? Do those signals truly indicate what, when and how much we should be eating? Is your craving For sweets at the end of a meal psychological or physical? Read on to Find out six essential principles of hunger and Fullness and how to use them in effective weight management.

1) Stop and Go Signals

Mechanisms that control earning behavior fall into two very broad categories: "stop" signals and "go" signals. Hunger and appetite are the big go signals: satiation and satiety are the main stop signals. Using the analogy again, here's a primer on the way work.

green

Hunger is a primarily physical sensation that drives a need to eat. Hunger signals can include a grumbling stomach or difficulty concentrating.

Appetite is primarily a learned psychological desire to ear, such as a craving, that can occur with or without hunger. When you're already full from a meal, appetite comes into play when the dessert cart rolls around.

yellow

As you eat, a variety of physical indicators tell your brain when you've had enough. Nerve receptors in the stomach and hormones throughout the body are activated, as well as the satiety centers of the hypothalamus in the brain.

Red

Satiation means you're full from the current meal and it's time to stop eating. Some foods (like protein) are more satiating than others (like fats).

Satiety is how long you'll stay full; in other words. how long the light will stay red before turning green again. Many factors affect satiety.

A long list of hormones and physical mechanisms trigger hunger and satiety. For example, low blood glucose and a hormone called neuropeptide Y (NPY) are thought to stimulate hunger. Conversely, hormones such as serotonin and cholecystokinin (CCK) and many nutrients in the blood contribute to satiety. Despite the laundry list of physiological hunger and satiety triggers, appetite is what most often determines how much we eat.

2) Hunger Scales Have Pros and Cons

Some nutrition experts believe one answer to weight management lies in letting internal hunger and satiety cues rather than external appetite cues determine what we eat. A hunger scale is often recommended to "reconnect" someone with his or her body's natural hunger and satiety cues.

"I use the hunger scale all the time with my clients. I think it provides a language for communication, as opposed to relying on just adjectives," states Nancy King, MS, RD, a Los Angeles-based nutritionist. She advises starting with a blank 0-10 scale and personalizing each number.

The first step is becoming familiar with how your body communicates. "When was the last time you felt something vaguely called hunger?" asks King. She recommends actually touching the parts of the body where you identify those feelings. "Then think, when was the last time I felt some fullness? Where did those thoughts or feelings come from?"

After you have the basics down, start looking at the 0-10 gradations, with 0 being extremely hungry and 10 being "Thanksgiving-dinner full." Keeping a journal of when, what and why you eat is one way to start filling in the scale.

For example, if you're at a "2" you may feel like you can't focus on anything but the thought of food, and you may generally feel confused and irritated. At an "8" you may feel uncomfortable pressure in your stomach and wish you had stopped eating sooner Continuing with the stoplight analogy, you might have a green light to eat between 1-4, a yellow from 5-7 and a red light at 8.

Though the scale can help you reconnect with your physical sensations, you wouldn't want to base your entire diet upon it. "There's so much more to hunger ... even though you might be physically full, you may still want more or want something sweet at the end of the meal," King explains. Physical signals could theoretically regulate how much you should be eating, but in practice it's simply unrealistic.

"A person might also become frustrated in differentiating between a 7 and 8 or a 3 and 4," notes Los Angeles-based nutritionist and American Dietetic Association spokesperson Gail Frank, DrPH, MPH, RD. Some people may not experience 10 distinct levels, so it's up to you to fit the scale to your personal hunger experiences; you might want to use a 0-5 scale instead.