Why do I feel sleepy after every meal?

Answer 1

Why we need a siesta after dinner
15:42 05 June 2006
NewScientist.com news service
Linda Geddes

The mystery of why we often feel sleepy after eating a big meal may finally have been resolved. Researchers have discovered that high blood glucose levels, similar to those after eating a big meal, can switch off the brain cells that normally keep us awake and alert.

The findings make evolutionary sense since sleepiness could be the body’s way of telling us to relax and conserve energy once we have found and eaten our food, says Denis Burdakov of the University of Manchester, UK, who led the research.

“It has been known for a while that people and animals can become sleepy and less active after a meal, but the brain signals responsible for this were poorly understood,” he says.

Burdakov’s team studied a group of brain cells called orexin neurons, which are found in the hypothalamus and produce proteins called orexins that are essential for maintaining normal wakefulness in humans. These neurons are less active at night and when they malfunction this can lead to narcolepsy, where sufferers cannot stay awake.

Firing rate
Previously, researchers have shown that orexin neurons can be inhibited by glucose, but it was not known how sensitive they were. Burdakov’s team exposed orexin neurons to subtle changes in glucose levels similar to those that occur in the blood during daily cycles of eating and hunger, then measured their firing rate.

“What we discovered is the activity of the neurons can be turned off by minute elevations in glucose associated with normal meals,” says Burdakov. The glucose is thought to act on potassium ion channels in the neurons’ membrane.

He believes this could explain why we naturally feel sleepy after a meal and also why it can be difficult to sleep when we are hungry, since the activity of the neurons would be higher when there is less glucose in the blood.

“We think orexin neurons make sure that we are awake and alert when hungry, in order to ensure optimal food-seeking,” Burdakov says. He adds that it makes evolutionary sense for animals to turn off their wakefulness and conserve energy once they have eaten their food, since it could be risky or wasteful to expend too much energy looking for more food.

Obesity trigger
Changes in the sensitivity of orexin neurons to glucose could lead to obesity, Burdakov speculates.

Orexin neurons are known to help regulate appetite and metabolic rate, and when they become faulty this can trigger late-onset obesity. Researchers are currently trying to understand exactly how orexin neurons interact with other brain circuits involved in appetite regulation.

“The role of orexin neurons in the control of numerous central nervous system processes makes the discovery of their ability to sense small changes in glucose potentially quite important,” says Joel Elmquist at the University of Texas Southwestern Medical Center in Dallas, US, writing in a commentary accompanying the paper in Neuron.

This is because it means a whole range of physiological processes can be regulated by the amount of fuel that is available. “Dysfunction of glucosensing may have profound effects on wakefulness and coordinated autonomic responses,” he says.

Journal reference: Neuron (vol 50, p 711)

Answer 2

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Answer 3

Well depends what you mean by every meal, what is it that you eat. Pasta (carbs) and Turkey tend to make some people sleepy. While some people can get sleepy by the end of a meal nurtured by nuts and grains. So everyone is diffrent but pasta and turkey are the most common, and tend to make people sleepy.

Answer 4

You are sleepy after your meals because all of your body's resources are being used to digest the food you just ate. We usually eat only cooked food. The natural enzymes in food which help it digest in our systems are destroyed at 118 degrees. That leaves only what is available in our bodies for the digestion process. If you begin taking a good enzyme supplement, you won't feel so tired after your meals because the enzymes will help in the digestion process. I also noticed that switching to the blood type diet helped me a lot with both symptoms of tiredness and having a stuffy nose after eating.

Answer 5

Friend.... Ur question according to my understanding is " why u r getting sleep after eating"....

I guess this might be the reason. Every time we eat something or any meals, there will be some process for digestion. And that digestion process will lead to consumption of some energy. That is equivalent to doing some work physically. So, its obvious that we get sleep when we work physically. So that will be the reason for feeling sleep. Did i answered?

Answer 6

feeling sleepy after a meal is pretty normal. since your body needs more blood supply in the stomach region to digest the food, one feels like sleeping as there is lesser blood supply to the brain. it all depends how much you eat. it happens with me all the time, but i cant just quit having "paranthas" in the morning.

Answer 7

Maybe you're not eating enough/right. Are you skipping breakfast, or any other meals? That could be your problem. Or, maybe you're not getting enough sleep. Try going to sleep early tonight and skip the studying for one day. Trust me, it's not even worth studying when you are extremely tired b/c you won't be able to retain information!

Answer 8

that happens to me when I get really full...i get cold too for some reason. Maybe it's because the body is working hard to digest all the food.....that's really just a bad guess from a clueless 14 year old...but I'm not really sure why either.....

Answer 9

You may have symptoms of a sleeping disorder but the best place to know for sure would be to get some advice from Web MD.

Answer 10

Because of secretion of a fluid called serotonin after having foods containing high carbohytrates.