system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5 How come If u wait too long to eat your appetite goes away?
gpt
Hunger is caused by the hormone ghrelin. When the hormone wears off (or we eat) we stop being hungry. We develop a natural ghrelin cycle, based on our usual times in which we eat. You're not hungry in the morning because you haven't eaten, you're hungry in the morning because you usually eat in the morning, your body expects it, and releases ghrelin at that time to reinforce the cycle. People who routinely skip breakfast (or any meal) usually stop getting hungry around that time, as their body's ghrelin cycle adapts to when it usually eats. No ghrelin, no hunger, to an extent. Carbs release insulin into your body, insulin triggers the release of ghrelin, which is why the old saying of being hungry an hour after eating Chinese food exists. Fighting through the feelings of hunger means ignoring your ghrelin cycle. Once it passes, you're not hungry any more until the next phase in the cycle comes.