Why do you eat?
It’s a simple question that can be surprisingly difficult to answer.
There are many answers to this question, but if you ask around I think you’ll land on the consensus that most people eat to satisfy a feeling of hunger. You may not know why you “feel hungry”, but it’s unpleasant and you’d like that feeling to go away. As it turns out, the opposite of hunger is “feeling full”, so many of us are also eating to chase the sensation of “feeling full”. My guess is that you’d intuitively agree with this, but may have never really put much thought into it. Here’s why you should:
“Feeling full” is just that, a feeling. Like many emotions and feelings, it can lead us to act illogically.
There are physiologic reasons why you “feel hungry” and “feel full”. Understanding how these feelings and urges work will help to uncover reasons why they’re misleading. Enter ghrelin…
Ghrelin is high before you eat and low after you eat
Ghrelin is a hormone released by the stomach wall. Its job is to tell the brain how much food is in the stomach. Here’s how it works:
When your stomach is empty the walls are in a relaxed state, ghrelin release is high. When ghrelin is high, it tells your brain that you are hungry.
As you eat, your stomach stretches out. When your stomach walls stretch, ghrelin release is low, which then tells your brain that you are full.
So if you “feel hungry”, it doesn’t necessarily mean that you need more food. Instead, it just means that your stomach isn’t as stretched out as it usually is. It’s important to note here that the more you eat, the more your stomach will stretch. So it’s often the case that you “feel hungry” simply because you haven’t yet eaten as much as you normally eat. Notice that this says nothing about what you need or what’s healthy; it’s simply a comparison to the way that you’ve eaten in the past.
The ghrelin delay
Because of this ghrelin mechanism, there is a slight lag or delay in “feeling full”. Even when your stomach is fully stretched, it takes time for your brain to process that lack of ghrelin in your bloodstream and tell you that you “feel full”. For this reason, we should be aware that we should probably stop eating before we hit the sensation of “feeling full”.
Important takeaways
- Feeling hungry doesn’t mean that you need food. It just means that you haven’t eaten as much as you normally do.
- You have usually eaten enough before your brain receives the “I’m full” message.
- If you keep eating enormous meals, you will feel hungry more often.