Stuart, London<\/em><\/p>\n Dear Stuart,<\/p>\n Well, my first question to you is how soon after that meal are you going to attempt to go to bed?<\/p>\n If you have a large meal just before you sleep, this can be disruptive to sleep because of the digestion cost and the discomfort it can cause. If you\u2019re digesting a big meal, it\u2019s quite a big effort to digest it \u2013 the fact that people report feeling uncomfortable after a particularly large meal is not simply coincidence.<\/p>\n The other bigger aspect that people are now looking at, though, is Chrono-nutrition \u2013 the practice of efficiently timing when you eat. As an example, if you think of having something large to eat very late at night, that meal falls at the end of your active period. You\u2019re not really geared up metabolically to cope with that meal then because the time it takes to clear from the system is longer than it would be earlier in the day. If you were to have the same meal for breakfast, though, you\u2019d be more primed to digest and absorb the fuel you\u2019ve taken on board.<\/p>\n On a more basic level, if you have a big meal at the beginning of the day, that then acts as fuel for the period that follows because you\u2019re using energy during your active period. If you have it at the end of the day, you\u2019re getting an influx of this fuel that takes longer to clear from the system, coupled to the fact that you\u2019re inactive and not demanding any fuel.<\/p>\n So is it bad for you to be eating at this time? Well, if you look at the literature \u2013 yes, it would be worse to have that meal at 10 pm than 10 am.<\/p>\n But it\u2019s not uncommon for people to energy load late in the day because, of course, people are working, travelling to and from work, doing other things outside of work, and so the opportunity to eat often isn\u2019t available until this time. Given that, what can we do to mitigate against it?<\/p>\n “In this country, we used to get most of our fuel in the middle of the day, and in Mediterranean countries, they still tend to have their big meals at lunchtime or the afternoon rather than late at night”<\/p><\/blockquote>\n Yes, we could have breakfast like a king, lunch like a prince, dinner like a pauper \u2013 as we used to do. In this country, we used to get most of our fuel in the middle of the day, and in Mediterranean countries, they still tend to have their big meals at lunchtime rather than late at night.<\/p>\n However that’s not to say they\u2019re not eating anything late at night \u2013 often it\u2019s actually later than we are \u2013 but the energy distribution is different. And even then, Mediterranean\u2019s tend to go to bed later and they space that meal out over a longer period of time. It\u2019s a lifestyle; not just the composition of what you’re eating but how you\u2019re eating it, sitting down at a table with your family, spreading that meal out over a couple of hours rather than shovelling it in your face as quickly as you can, which happens to be 10 at night.<\/p>\n But going back to how we can mitigate, let\u2019s say we haven\u2019t got the luxury of being able to live like a Mediterranean and go home at lunchtime to have a three-hour siesta, relax with family, then go back to work. The other way you can manage it is to look at the rest of the meals in your day.<\/p>\n If you have a big meal at 10 pm one night and you wake up at 7 am the next morning, you might want to refrain from eating or look more carefully at what you\u2019re eating around that time, You could push your breakfast to later to extend the fast and give yourself extra time to clear what you had the night before from your system. In doing this, you\u2019re effectively moving your eating window to later, starting later and finishing later.<\/p>\n When you look at shift workers \u2013 which is where a lot of the evidence comes from that eating late at night is worse for you \u2013 the overriding issue is that you have a double-whammy of eating in the middle of the night, but not doing it consistently. Instead, they do it for maybe two days a week and for the rest of the week they eat in a normal pattern. So they\u2019re eating at the wrong times of day not consistently, but intermittently or for a short period of time.<\/p>\n That\u2019s where new evidence comes in about how you can train your body to be better able to cope with eating at a particular time of day. It might be against your central circadian rhythm, but if you\u2019re doing that meal pattern late at night all the time, then your gut can be trained to cope with it and get accustomed to that time frame.<\/p>\n “It\u2019s almost in our psyche that we can\u2019t go longer than an hour without having something to eat or drink, grabbing a coffee here or a croissant there. We\u2019ve been brought up in a culture where we have a constant grazing habit”<\/p><\/blockquote>\n The problem with society today, though, is that we eat all the time. It\u2019s not just that we\u2019re having a big meal after 10 pm; we\u2019re eating consistently from 7 am right the way through to midnight \u2013 snacks, drinks and meals combined. It\u2019s almost in our psyche that we can\u2019t go longer than an hour without having something to eat or drink, grabbing a coffee here or a croissant there. We\u2019ve been brought up in a culture where we have a constant grazing habit.<\/p>\n So, if you\u2019re having these 10 pm meals, the best advice I can give is to be mindful of what you\u2019re going to eat the following day. If you know you\u2019re going to eat lots at the end of the day, maybe don\u2019t have any recognised breakfast, or push breakfast to later in the morning, or get rid of that frappuccino you\u2019re having on the way to work and replace it with a water or tea \u2013 something that doesn\u2019t give you a calorie load.<\/p>\n There are reasons for this. First and foremost, we often overlook the energy cost of digestion. When you have a large meal \u2013 particularly if it was a rich meal \u2013 it takes a lot of effort to digest and absorb it.<\/p>\n That manifests as heat; you might even feel your belly become warm or start to feel hotter overall. What\u2019s happening is known as diet-induced thermogenesis \u2013 the thermic effect of feeding \u2013 which represents all the energy it took up to digest that food, break down and synthesize proteins, move the gut around to churn that food, secrete liquid and enzymes into the gut. You then have to actively use energy to transport the digestive products of that food through the gut wall and into the blood. All that contributes to a drain of energy which makes people feel tired.<\/p>\n The other thing that often happens \u2013 particularly if you have a large carbohydrate load in that meal \u2013 is that you produce a lot of insulin. You might overproduce insulin and consequently absorb more sugar from the blood than you\u2019ve imported, translating to a slight dip in blood glucose, which is the fuel your brain uses, and so this might contribute to feelings of tiredness.<\/p>\n But while a large meal might make you feel sleepy, the quality of the sleep you\u2019re going to get is still compromised. You\u2019re going to fall asleep with all that food still in your gut, still digesting and absorbing, and it\u2019ll take you around eight hours to clear that food from your system. As dawn breaks, you probably still have remnants of the meal from the night before in your blood.<\/p>\n It\u2019ll also dehydrate you. When you digest a lot of food, you draw liquid out of the body. So yes, you might fall asleep, but you\u2019ll likely wake up in the middle of the night to get a glass of water, or go to the toilet in the same way as if you\u2019ve gone to bed having lots of alcohol. You\u2019ll collapse as though you\u2019re comatose, have a rubbish night\u2019s sleep and feel terrible the next day.<\/p>\n _<\/p>\nSo is there any truth in the feeling of tiredness after a large meal, or that eating can aid<\/em> sleep?<\/h4>\n