The Surprising Science Behind What Makes You Hungry

| 2 min read

Everyone knows what hunger is—that mouth-watering, stomach-grumbling, cookie-craving feeling—but have you ever wondered what actually causes it? It turns out to have less to do with your stomach than with your brain—more specifically, the hypothalamus.
Here’s what happens: If it’s been a few hours since you’ve eaten, your blood sugar levels begin to get low. At this point, your body increases production of two chemicals: ghrelin and Neuropeptide Y. The hypothalamus interprets the spike in those chemicals to mean you’re hungry, so it increases your appetite and desire for food (particularly sugary and starchy foods). As a result, the stomach begins to growl and contract and you head for the kitchen.
Once you eat, something else happens. Another chemical, this one called leptin, increases, which puts a halt to the Neuropeptide Y production, signaling your brain to feel full. At the same time, food digestion spurs the release of a chemical called cholecystokinin, which also makes you not hungry anymore.
There are times when other things can be confused for hunger. Some of the other triggers that can cause you to reach for the nearest candy bar include:
  • Dehydration
  • Sleep deprivation
  • Stress and emotion
  • Seeing or smelling delicious food
Research shows that eating when you aren’t physically hungry (also known as pleasure eating) activates the brain’s reward centers, which overpowers the physical hunger cues mentioned above and makes you want to eat more and more. If you think you might not be physically hungry, try these tips to overcome your cravings.
And if you are interested in learning more about what foods affect your brain, check out these blogs:
Photo credit: mst7022

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