It is common to hear elderly in Portugal saying that dining and then going to sleep has a bad impact on one's health (apparently it is not only in Portugal).

From a National Institute of Health ncbi.nlm.nih.gov article we see that some foods may affect sleep

Such studies highlight a potential effect of macronutrient intakes on sleep variables, particularly alterations in slow wave sleep and rapid eye movement sleep with changes in carbohydrate and fat intakes.

However it is not clear to me how harmful the alterations in slow wave wave sleep and rapid eye movement are for one's health.

I do not want to get into much detail about problems that may result from eating before sleep, giving freedom to reflect upon them. They seem to be various, such as reflux, quality of sleep, or even weight gain, which, from healthline.com is considered conventional wisdom:

Conventional wisdom says that eating before bed causes weight gain because your metabolism slows down when you fall asleep. This causes any undigested calories to be stored as fat.

Is sleeping right after a meal bad for one's health?

Related but raising a different concern: Does eating just before sleeping cause nightmares?

  • Is it that sleeping right after eating a meal is bad for health, or that unhealthy people feel excessively sleepy after a meal? This Nature paper suggests the latter.
    – Richold
    Commented Feb 19, 2021 at 13:10
  • 1
    @Goncola - Medically, it is much harder to prove causation rather than correlation. For causation, you need a study where you make healthy people eat and then sleep for a few years, and you see if they become unhealthy. That is an ethically difficult study. Google "postprandial sleep" as a phrase.
    – Richold
    Commented Feb 19, 2021 at 15:27
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    "This causes any undigested calories to be stored as fat." - if it's not digested, it can't be stored as fat! Commented Feb 21, 2021 at 20:35

2 Answers 2


Study shows eating at night increases risk for obesity and diabetes;


  • 11
    At the moment this is a rather limited answer. Please quote a little of the source to show that it supports your claim (and to protect against link rot). Also, follow up this newspaper article and find the original article it is based on - see if that actually matches what the apparent experts say.
    – Oddthinking
    Commented Apr 26, 2021 at 0:15
  • That article talks more about making breakfast the biggest meal of the day than eating before sleep.
    – Joe W
    Commented May 25, 2021 at 16:28

Sleeping after eating a meal, or more specifically, laying horizontally, may lead to acid re-flux. So yes, very bad. There are also considerations to be taken into account for diabetes, insulin, and meal times and sleep time.


Time it right. Wait at least 3 hours after eating before lying down. Improve your posture. Try standing up straight to elongate your esophagus and give your stomach more room.


Sleep with the head of your bed raised 6 to 8 inches so that gravity can help your stomach acid stay in your stomach. Don't eat for 3 to 4 hours before you lie down to sleep at night.



Lifestyle Modifications

... Reduce weight if too heavy. Do not eat 2-3 hours before sleep.

Note: WebMd does list sources

  • 5
    Neither Healthline nor WebMD are reputable sources....
    – user141592
    Commented Feb 19, 2021 at 19:12
  • 10
    Those are still not good sources for health related claims. On this site, people typically cite actual medical research papers to support health related claims.
    – user141592
    Commented Feb 20, 2021 at 6:37
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    I would be skeptical of any claim that requires gravity for the operation of a healthy digestive tract. The digestive system is not a straight tube that doesn't work when horizontal. Commented Feb 26, 2021 at 9:22
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    @paulj Can you provide a specific title? I have actually read a number of texts concerning digestive anatomy and physiology as well as designing apparatus for digestive studies in laboratory & clinical settings, most of which are done supine. If someone has trouble lying down after a meal, it's most likely a problem with the food they consume or a digestive tract disorder, not the fact that they are lying down. Commented Mar 1, 2021 at 20:42
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    The don't eat 3-4 hours before bed is on NHS website nhs.uk/conditions/heartburn-and-acid-reflux albeit as noted for GERD/Acid Reflux but that does cover a noticeable proportion of people and I suspect under reported.
    – mmmmmm
    Commented May 26, 2021 at 15:23

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