Does weightlessness affect hunger? (Beginner)

Recent studies have suggested that on earth, people tend to eat roughly the same weight of food every day, and that perhaps the weight of food (rather than volume) is the way your body determines when you're full/satisfied. My question is: Are astronauts always hungry in space since their stomachs do not register the weight of food in their stomach? Do they tend to eat more food--by weight--than they do on earth? What about on the space station when your body adjusts to zero-gravity? Do eating habits change then? Thanks for satisfying my curiosity. :)

Interesting question! I did some research online and here's what I came up with:

Hunger is caused by a combination of physiological and psychological components. There are a number of theories about both. They are summarized pretty well at this website.

As far as I can tell from researching the problem online, there isn't a lot of evidence that hunger is related to the weight of food in your stomach. According to what I've found, astronauts often eat less than they normally would on the ground, but any connection between weightlessness and lack of hunger is not directly due to the weight of the food, but more likely due to other physiological effects. For instance, Canadian astronaut Chris Hadfield points out in this article that taste is slightly diminished in space, like they have a head cold, making food less appealing. Also, astronauts are pretty busy, so it may just be that they don't think about eating as often when they are in space.

I hope this helps. I'm no expert on these things, but it is an interesting topic!

Page last updated on June 24, 2015.

About the Author

Ryan Anderson

Ryan is a research fellow at USGS in Flagstaff, AZ and is a member of the Curiosity ChemCam team. He also loves explaining all aspects of astronomy. Check out his blog!

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