Why Eat: Exploring Different Types of Hunger

Why eat?

If I ask you why you're eating something, the answer might be, "Because I'm hungry." But what exactly is hunger? Is it the uncomfortable rumbling in your stomach that you need to pay attention to? If that's all, any edible food that makes the feeling of hunger disappear will work.

Perhaps it's not the rumbling of your stomach, but rather a craving, a specific sensation produced by a particular food, such as ice cream, potato chips, or even soup. Or perhaps you're not hungry, nor are you craving anything. In fact, you might not have been thinking about food at all, but when you walk past a pastry stand in the shopping district and smell the aroma of freshly baked chocolate chip pastries, suddenly you're "hungry," and the only solution is Mrs. Fields' Cookies (a famous American dessert company).

To develop bodily intelligence, it's necessary to carefully examine what happens when you say you're hungry. The word "hunger" generally indicates a desire to eat, but it can encompass many different interpretations. Because an element of bodily intelligence is understanding the motivations for eating, this chapter will explore the characteristics of the various reasons that trigger eating. Learn the signs that will help you determine what type of hunger you're experiencing.

When you know exactly why you want to eat, you can often satisfy your need with less food. Sometimes, not eating anything is enough. For example, if the reason for eating has nothing to do with the taste of chocolate, there's no reason to eat it. Even if you really love chocolate, if your stomach is telling you it's been four hours since your last meal, you can eat something more nutritious, which might give you the same satisfaction. Consider the following three examples:

Sara is a junior in college. It's 11:30 a.m., and she's in English class listening to the professor analyze Shakespeare's sonnets. She's starving and can hear her stomach rumbling; she hopes the boy sitting next to her hasn't heard. She starts planning what to eat for lunch, glancing at the clock to calculate how much time she has left before class ends. As soon as the professor announces the end of get out of class, she heads straight to the cafeteria in the student building and orders a chicken tostada.

Cal had eaten dinner an hour earlier, and his wife was putting their two young children to bed. He was sitting on the sofa watching Monday Night Football (an ABC television program). During halftime, a commercial for doritos came on. So he got up and went to the kitchen to get something to eat. He grabbed a bag of potato chips and a bottle of beer, and returned to his seat before the second game started.

Margo was in high spirits. Although she'd been in sales for a while, she'd recently passed her real estate exam and started working for a local agent. She'd been showing houses to a picky couple, but they never seemed quite satisfied. This morning she called them to arrange a viewing of a house she thought they'd like. The wife told her they'd already agreed on a price with another agent. Margo hung up, starting to wonder if she'd switched to the wrong profession, and casually grabbed a handful of candy from a bowl on her colleague's desk.

The examples of Sarah, Carl, and Marg illustrate three of the most important reasons for eating: eating because of hunger, eating in response to external food cues, and eating to relieve unpleasant emotions. This chapter will examine the first two in detail; the relationship between emotions and eating will be discussed in Chapter Four.

Eat because of hunger

If you've ever missed a meal or two, you know what it feels like to be uncomfortably hungry, and this experience will likely become more and more frequent in your life. Everyone knows the rumbling in your stomach and the discomfort of dizziness, but scientists disagree on the causes.

Traditional thinking holds that hunger is caused by a decrease in the body's energy supply. On one hand, the hypothalamus in the brain sends signals that blood sugar is low, while on the other hand, the contractions of the stomach muscles signal that it is empty. Sometimes, the sound of these contractions can even be heard by people nearby. According to this logic, when you eat, the glucose (or blood sugar) in your blood increases, and the feeling of hunger disappears.

Another viewpoint argues that hunger has nothing to do with food scarcity. According to this view, even if you are slim, your body still has enough energy to last a month. For obese people, they could survive for a year without eating, relying solely on their body fat. The cause of hunger is not nutritional deficiency, but rather the changes that occur in the body when food is available and you are ready to eat.

When it's known that mealtime is approaching, insulin is released from the pancreas. Insulin removes glucose from the blood, causing the feeling of hunger. However, even without eating anything, glucose levels return to normal on their own. According to this logic, when Sarah sat in the classroom looking at the clock, her anticipation of lunch triggered the release of insulin. If she were unaware of the time or how long it had been since her last meal, insulin wouldn't be released, and she wouldn't feel hungry.

If hunger were solely a result of food scarcity, the feeling should intensify as the frequency of fasting increases, but this is rarely the case. If you forget about the hunger, it will eventually disappear on its own. You'll feel your stomach contracting when you miss lunch, but it will likely calm down after about an hour. You'll no longer feel the contractions, and then dinner will arrive, at which point your pancreas will secrete insulin again. If you persist in fasting (which I don't recommend), the hunger will disappear after five days of fasting.

Anorexic individuals who have undergone prolonged fasting, even after days or weeks without food, still say they are not hungry; they are not lying. I once worked with an anorexic woman who, despite not eating for four days, still said she wasn't hungry. Meanwhile, during our class, my stomach started rumbling because I was half an hour late for lunch.

Dr. Paul Rozin, a researcher at a university in Pennsylvania, has demonstrated that psychological factors can easily overcome hunger and are therefore a more significant factor in deciding whether to eat or how much to eat. He studied two men who suffered from severe amnesia due to brain damage. Their memory loss was so severe that neither could recall events that occurred just minutes before.

Dr. Rozin fed them lunch, and less than half an hour later, he fed them a second meal. Although they were full after lunch, none of them remembered what they had just eaten, so they ate a second meal. Therefore, hunger was not the reason they ate. Seeing and smelling food, along with the loss of memory of their recent meal, was enough to trigger them to eat.

While the exact mechanisms of hunger are not fully understood, one thing is clear: hunger is at least partly controlled by psychological factors, such as the expectation of eating and the loss of the last meal. Although everyone knows how unpleasant hunger feels, it's possible to go without food when there is none available. However, hunger is not the only factor that leads to the urge to eat.