If you struggle to sleep, you’re not alone, because more than one third of adults in the UK complain of insomnia and women appear to be especially badly affected. In my book Va Va Voom: the 10-Day Energy Diet , I explore the impact of insomnia on our energy levels and the diet and lifestyle factors that can improve sleep.
It’s not just what you eat but when you eat it that can make a huge difference to the quality and quantity of your sleep, so here are my tips to help you get the timing right.
Here are the seven eating habits keeping you awake - and how to get your timing right...
1. Your blood sugar is too high - or too low
If you have no problem getting off to sleep but often wake up a few hours later for no apparent reason, it could be a blood sugar issue.
Going to bed with high blood sugar (if you’ve eaten sugary foods and refined carbs) will activate the insulin response which removes sugar from the blood and your blood sugar will start to drop. Low blood sugar levels then generate an emergency response, which releases the stress hormones cortisol and adrenaline, sending your body into red alert. You’ll either wake up or have a very restless sleep that will leave you tired and unrefreshed in the morning.
Going to bed hungry is not a good idea either. If your blood sugar is already low by bedtime, your stress hormones will already be activated, making it difficult for you to drop off to sleep.
What time to take action on blood sugar?
9 am. Balance your blood sugar from the off as it can be very hard to get off the seesaw of energy peaks and crashes once it starts. Avoiding sugary foods, focusing on whole grains at breakfast and lunch and ensuring you don’t leave more than four hours between meals generally will help to keep things stable so that you’re starting from a better base in the evening.
5-6 pm. If you’re in the habit of eating early with the kids, you may need to plan a small, balanced snack for later in the evening, such as one or two oatcakes with sugar-free nut butter, or some carrot sticks with about 50g of hummus. This will help to make sure that you don’t go to bed with low blood sugar and are unable to drop off - and it won’t send your blood sugar skyrocketing, so you are crashing when you should be sleeping.
7-8 pm. Don’t fall into the trap of the quick and easy white pasta and pesto or tomato sauce routine, as that’s just asking for trouble! Your body will burn through a meal like that super-quickly. Make sure that at least a quarter of your evening meal consists of a protein portion, such as a chicken breast, salmon steak or 125g of cooked quinoa.
Protein is harder to digest and will slow down the release of carbohydrate in the body, which will keep you going for longer. Serve it with vegetables and/or wholegrain pasta or brown rice. These are excellent sources of complex carbohydrate, which your body will break down more slowly than refined white versions and will keep your blood sugar nice and stable.
9 pm. Steer clear of large helpings of chocolate, sweets, crisps and alcohol as you settle down to watch TV, as this could undo all your earlier good work and send your blood sugar rising just as you’re ready for bed. Everyone’s glycaemic sensitivity is different but generally, one or two squares of chocolate won’t be an issue, but a whole bar or a bowl of crisps would be.
2. Caffeine too close to bedtime
Caffeine is a powerful natural stimulant that can disrupt the nervous system and is a common cause of insomnia. The difficulty is that everyone metabolises caffeine at a different rate - it can be incredibly frustrating to watch your partner enjoy a double espresso after dinner with no apparent ill-effects while you can’t even enjoy one after lunch without facing the prospect of a sleepless night.
Caffeine is broken down by an enzyme in the liver called CYP1A2 and our sensitivity to caffeine can be determined by our genetic ability to produce effective amounts of this enzyme. Other genetic factors, age and medical conditions may also play a part in caffeine sensitivity .
A few people are hyposensitive and don’t experience many effects from it. Those who are hypersensitive will take a long time to process caffeine and may experience palpitations, nervousness and insomnia. For people with normal sensitivity, it takes about four to six hours for the body to process caffeine.
What time to take action on caffeine?
9 am. If you’re hypersensitive to caffeine, then you should probably avoid it altogether or drink it only in the morning.
1 pm. This is a good time to switch from the blast of caffeine you get from a coffee to a green or black tea if you still want a little boost, as these contain about three times less caffeine than you’d get in a medium latte. Caffeine content will vary depending on how long your dunk your teabag though – you can double the amount of caffeine by brewing it for about five minutes.
4 pm. If you want to be ready for bed by about 10 pm, it’s time to switch to a caffeine-free option such as rooibos tea, herbal tea or decaffeinated coffee. This will give your system time to metabolise the build-up of caffeine well before bedtime.
8 pm. If you’re struggling to switch off, this would be a good time to take positive action by choosing a herbal tea, such as camomile or valerian which have a relaxing and calming effect. Remember that cola, energy drinks and dark chocolate all contain caffeine, so make sure you’re not topping up with caffeine by mistake.
3. Not metabolising your alcohol in time
You may be in the habit of enjoying the occasional nightcap if you struggle to unwind and feel that alcohol helps you to get to sleep. While you may drop off to sleep quickly, alcohol actually has a sedative effect which affects the quality of your slumber by disrupting your sleep cycles, causing restlessness and leaving you feeling tired and jaded in the morning.
The high levels of sugar in many alcoholic drinks or mixers will also disrupt your blood sugar, which could cause further sleep issues (see above) and middle-of-the-night waking.
What time to take action?
6-7 pm. On average it takes an hour to process a unit of alcohol, so if you like to have a quick drink to unwind after work, being smart about the number of alcohol units could make a big difference. A single gin or vodka contain just one alcohol unit whereas a 330ml bottle of extra-strength lager or a large (250ml) glass of wine contain about three units. This can soon build up to a sleep-disruptive level if you’re having more than one drink.
8 pm. If you’re in the habit of sharing a bottle of wine over dinner, this could directly affect the quality of your sleep. If a glass of wine is a must, consider using smaller glasses so that it’s easier to limit the amount you’re having and give your body time to process it before bed. Half a 750ml bottle at 8 pm (five units) won’t leave your system untill 1 am.
9 pm. Resist the temptation to settle down with an alcoholic drink in front of the TV, as time is ticking on and you don’t have much time to process the alcohol before bedtime. If you like to have a small nightcap, invest in a spirits’ measure and stick to one unit. You might be surprised at how little that is!
11 pm. If all is lost and you know you’ve overdone it, try taking a gram or two of vitamin C with a glass of water before bed. This can help to support the detoxification processes in the liver so you might not feel so tired and jaded in the morning.
4. Sensitivity to fermented, cured and aged foods
Tyramine is a compound that can be found in certain aged, cured and fermented foods such as strong cheeses (ie cheddar) or Roquefort - which may explain the ‘cheese gives you nightmares’ assumption. It’s also found in salami and other cured meats, pickles, sauerkraut or kimchi.
Tyramine triggers the release of the neurotransmitter noradrenaline (norepinephrine). This activates arousal mechanisms in the brain, increasing heart rate and blood pressure and preparing you for the ‘fight or flight’ response, which is the last thing you need when you’re settling down to sleep. High levels of tyramine may also trigger migraines in sensitive individuals.
What time to take action?
8 pm. If you’re prone to insomnia, it may be worth avoiding eating foods rich in tyramine in the evening.
5. Processed snacks and Chinese takeaways
Processed MSG (monosodium glutamate) is very commonly found in Chinese food and also processed products such as ready meals, chicken nuggets, crisps or tortilla chips. It is derived from glutamic acid which is an amino acid found in protein sources. It’s used as an additive to enhance dishes because it gives them the rich savoury flavour known as umami.
Some sensitive individuals experience unpleasant side-effects after consuming MSG which can include insomnia-inducing palpitations, headaches, fatigue and muscle pain.
7-8 pm. Cooking your evening meal with fresh ingredients such as meat, fish, dairy products, whole grains and vegetables will help you to keep MSG-free if you think it might be an issue for you. Some oriental restaurants market themselves as MSG-free, so you don’t have to miss out if this is your favourite food. Make sure you check labels of ready meals, prepared sauces and dressings so you know exactly what you’re eating.
9 pm. Beware of settling down to watch TV with a bowl of crisps, popcorn or other salted snacks as they may be a hidden source of MSG.
6. Taking B vitamins after 4 pm
While the average multivitamin and mineral shouldn’t be a real problem at any time, if you’re taking a separate B vitamin complex (which usually contains a higher therapeutic dose) avoid taking it in the evening. B vitamins play a crucial part in the body’s energy production process and may have an over-stimulating effect which could disrupt your sleep. Taking vitamin B6 before bed may also cause very vivid dreams in some people.
4 pm. If you’re using a B vitamin complex, aim to take your last dose no later than 4 pm so that you don’t run the risk of being too awake and alert at bedtime.
Magnesium , on the other hand, calms the nervous system, regulates our stress response and helps to relieve muscle tension and can be very supportive taken at any time of day. An Epsom salts (magnesium sulphate) bath could help you to unwind after a stressful day. Add two to three handfuls to a bath and allow the magnesium to absorb through the skin as you enjoy a long soak (minimum 20 minutes).
7. Eating heavy foods
If you have sensitive digestion, issues such as acid reflux or bloating can be a major contributor to insomnia. Even just overdoing portion size or indulging in rich or heavy meals, which include lots of red meat, cheese, cream or spices can cause indigestion which can keep you awake. Some people can get away with anything, of course, but if you’re not one of them, smart food choices in the evening could make a big difference to the quality of your sleep.
What time to take action?
7-8 pm. Too much starch (e.g. bread, rice, pasta) can be very hard work on your digestion and might leave you feeling bloated. Ideally it should represent about 25 per cent of the overall meal, roughly the same as your protein portion, with the rest being made up of vegetables. Protein-dense foods such as red meat can also be hard to digest and you may find that white meat or fish is easier on your stomach, especially if you’re eating later.
9-10 pm. Steer clear of rich, heavy food later in the evening. The larger portions of creamy, spicy or fatty foods that are characteristic of most takeaways could sit in your stomach for some hours, making it impossible to get off to sleep.
10 pm. Try a peppermint tea if you’re feeling uncomfortable. It can help to relieve heartburn and indigestion and may also reduce bloating .
And finally… calming foods to promote sleep
Tryptophan is an amino acid which acts as a mood regulator and has a naturally calming effect that promotes sleep. The body uses it to produce serotonin and melatonin , two hormones that are essential for healthy sleep cycles. Eating foods rich in tryptophan in the evening can help to calm the body and prepare it for sleep.
What time to take action?
8 pm. Poultry, dairy products, pulses, nuts, seeds and wholegrain oats are all good sources of tryptophan that you could include in your evening meal.
10 pm. Try a glass of warm milk to get you in the mood for sleep, or one or two oatcakes with hummus if you’ve got the munchies.