article on the psychological reasons for hunger.
If this is a subject that interests you, read the whole article. But to whet your, erm, appetite, I've pasted some snippets below:
"Here are a few of the things that can make you hungry: seeing, smelling, reading, or even thinking about food. Recent studies show that our physical level of hunger does not correlate strongly with how much hunger we say that we feel or how much food we go on to consume."
"Traditionally, hunger has been seen as largely physiological: our body becomes depleted and, to maintain homeostasis — the body’s status quo — hormones are released into our bloodstream and stomach to signal to our brain that it’s time to replenish its resources."
"Food deprivation, however, is generally not a problem in modern, developed societies. While our ancestors had to struggle to consume enough calories, we can just go to the fridge or the supermarket. From an early age, we learn to depend increasingly on external, socially, and culturally based cues."
"Foremost among those factors is the time of day at which you learn to be hungry. Your scheduled lunch break at work or your usual family dinnertime can reliably set your stomach growling. Even if you’ve had an unusually late or large breakfast, your body is used to its lunch slot and will begin to release certain chemicals, such as insulin in your blood and ghrelin in your stomach, in anticipation of your typical habits, whether or not you’re actually calorie-depleted."