Food coma: does it affect you?

This post explains why eating may exacerbate MS-related fatigue and what you can do to counteract it.

Do you suffer from food coma or excessive sleepiness and fatigue after eating a meal?

For ‘normal people’, we call this phenomenon postprandial somnolence or the siesta syndrome. Others refer to it as the ‘food coma’. It is my anecdotal experience that people with MS, in particular, people with more advanced MS, are particularly sensitive to postprandial sleepiness and fatigue. Why?

Postprandial somnolence (PPS) is a normal state of drowsiness or lassitude following a meal. PPS is a real phenomenon and has two components: (1) a state of perceived low energy related to activation of the parasympathetic nervous system in response to expansion of the stomach and duodenum from a meal. In general, the parasympathetic system slows everything down.  (2) A specific state of sleepiness, which is triggered by the hormone cholecystokinin (CCK) that is released in response to eating and changes in the firing and activation of specific brain regions. The reflexes responsible for PPS are referred to as neurohormonal modulation of sleep through the coupling of digestion and the brain. The signals from the gut to the brain travel via the vagus nerve.

My index patient is so affected by PPS that she now only eats one meal a day; her evening meal. She does this quite late so that she can crash and sleep about an hour after eating. She is a professional and needs to be functional during the day and finds if she eats anything substantial in the day she simply can’t work because of her overwhelming desire to sleep. We have tried caffeine, modafinil and amantadine to counteract PPS, but they only had a small effect in counteracting her PPS and allowing her to work productivel. Other patients reporting this have noticed some benefit from stimulants. Interestingly, my index patient, like a few others, finds carbohydrate-rich foods particularly potent at inducing ‘food coma’

Physiologists think that not all foodstuffs are made equal when it comes to causing PPS and it appears that glucose, or sugar, induced insulin is one of the drivers of this behavioural response. I suspect this why people who fast or eat very low carbohydrate or ketogenic diets describe heightened alertness and an ability to concentrate for much longer periods of time.

The reason for doing this post is to find out how common PPS is in the MS population and to give you some simple advice to counteract it. If you suffer from PPS can I suggest you review your diet and see if you identify ways to modify your eating habits and/or diets to coounteract PPS?

  1. You could adopt the above extreme solution and only eat one meal per day. Clearly, this not for everyone and is very difficult to implement. I say this, but many of my Muslim patients report feeling so much better during Ramadan when they essentially practice this type of eating pattern.
  2. You could reduce your meal size and cut out any carbohydrates from your daytime meals. You may find this difficult because it takes time for your metabolism to become optimised for ketosis. If any of you are interested in the science of ketosis I have written a Medium post on ketogenic and low-carbohydrate diets.
  3. Some of my patients find micro-meals helpful, i.e. instead of large meals you eat multiple small snacks during the day.
  4. The judicious use of stimulants. I tend to recommend caffeine, followed by modafinil and them amantadine. Please note you should probably not take stimulants later than about 3-4 pm as they have a long half-life and can cause insomnia.
  5. Some of my patients have also reported that exercise has helped them deal with PPS. I am not sure how exercise works except by possibly lowering glucose and insulin levels and improving insulin sensitivity. The latter will reduce hyperinsulinaemia that will not only cause PPS, but is an impotant driver and component of the metabolic syndrome.

Please note that PPS will be worse if you suffer from a sleep disorder and suffer from daytime sleepiness. Most pwMS have a sleep disorder so there is little point in focusing on PPS and ignoring the elephant in the room.

If you have a few minutes to spare can you please complete this survey and let us know if you come across any other effective treatments to manage your PPS.

10 thoughts on “Food coma: does it affect you?”

  1. I suffer from PPS. I also suffer from gut dysmotility due to MS. I have to eat small meals regularly or the dysmotility is a nightmare so one meal a day or fasting isn’t an option in my case. I manage the PPS by meditating for 10-20 minutes after my breakfast and lunch. It really helps and allows me to keep working effectively.

  2. Funny i just finnish my 3 day fasting, this time was a bit dificult

    What i suffer is when i eat a meal at mid day sometimes i feel dizzy and that can last 4, 5 h

    One thing that help me (besides fasting) a lot is eating in 8 h time window (between 13h and 20h)

    And i fast for 3or 4 days 3 times a year

    Nice post


  3. I started to notice pps a few years ago, asked my neurologist why it was happening with no sensible response. I mainly suffer after my evening meal and have real problems getting back to my front room. It lasts an hour and is quite unpleasant. It’s nice to now find the answer.

  4. I didn’t realise this was a thing! I thought it was related to body temperature after a hot meal hence a slump and increased fatigue.

  5. I snack during the day, little and often and I do not suffer any sleepiness during the day. In the evening after I have my main meal I am totally wiped out but pretty much back to normal within a couple of hours.Not always a high carbo-hydratelevel in my diet. Quite simply eating more than a couple of bits of bread and some cheese and I’m done for. Never tried stimulants, coffee does not keep me awake.

    Nice to know that there is a reason for the fatigue and its not just because of wine with the meal. It has only become a serious issue in the last 18 months, diagnosed in 1995 and medically retired in 2012.

  6. Intermittent fasting helps me a lot. If I have a busy day, I often won’t eat till late afternoon. It helps my energy levels immensely. After the meal though, I’m too tired for anything other than TV.

  7. Prof G, you are the top innovative, research and deep knowledge of MS. I have learned a lot from your blogs and use many of your research conclusion.
    Besides the huge Food coma, I have also Vagal reflex previous to bowel movement, with symptoms start more than 30minutes and continue later for few more

  8. My jaw just dropped, I have experienced this for some time and never thought it could be related to MS. I suspected it but never thought it had a name. I seem to be able to make manageable through portion control and meat avoidance.

  9. Hi Mr.Barts,
    it’s a very interesting blog. I suffer about 20 years and the last years are so heavy that I am must sleep after the meals.
    Here some points that I find out, maybe useful for others:
    1- carbohydrates with glycemic index and fat do the most sleepiness. Meat without fat, the most vegetables and boiled potatoes causes almost no fatigue or sleepiness. Potatoe is really interesting, because even brown rice do sleepiness, not not boiled potatoes. But 2 spoons fat with potatoes, and I need a bed.
    2- it starts 1 hour after the meal and lasts 3 about hours
    3- i have hypotension and I am slim (1,70m 58kg). I find out that some nights were I feel very good and do some fitness, the mornings I feel very dizzy. General mornings is always the worst time, evenings I feel much better. But i find out again, that the better feeling is not correlated to the hour or daylight, it is related with the absolute time from the wakeup.
    My theory is maybe that water in the blood and so the blood pressure falls down during the night and the brain gets not enough sugar and oxygen maybe.
    4- the sleepiness doesn’t occur if I do heavy fitness exercises after the meal. But such activities like walking has no positive effect, it must some strong power burning activities.

    I will be glad to hear some news at this page.
    Cheers from Munich

  10. I’ve been complaining for years that after I eat I feel incredibly sleepy. Someone just mentioned a friend of hers who literally falls asleep after she eats. I’ve been testing the hypothesis, and I believe I have some of this disorder. I also have MS. Thanks for the work you’re doing on it.

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