This is what happens to your body when you eat at bedtime

Give your sleep a helping hand by reading our expert explainer on how to have a better night's sleep, and avoid the late-night nibbles with these healthy, filling meals that won't leave you hungry. Otherwise, learn how ayurveda can help digestion.

It’s the end of a long day and, after clearing up the kitchen post-dinner, you’re on the sofa, feet up, tuned into a Netflix series.

But despite only having just had your last meal, the urge to indulge in a little nibble is still there.

It could be habit or boredom. It could be a craving for your favourite ice cream which you know is stashed away in the freezer. Or, it could be genuine hunger.

Whatever your reason for snacking, you’re not alone – it’s practically a national pastime.

According to YouGov nearly half of Brits (46%) have one snack a day and one in ten admit to grazing at least three times a day. Crisps are the nation’s preferred snack, closely followed by cookies, cakes and pastries. Just 22% of people go for the healthier choice of fruit and veg.

By the time evening rolls around, it’s about grabbing what’s easiest. According to a UK Snacking Trend Report, 63% of people look for indulgence in their evening snacks as opposed to convenience. Well, let’s be honest, you’re unlikely to reach for a bowl of steamed broccoli.

But evening snacks aren’t always bad, and can even be the right option.

“Late-night snacking does have its place for people who may not have been able to have an evening meal due to work commitments or late gym sessions,” says Dr Sarah Schenker, a BDA Dietitian and Nutritionist.

However, certain foods eaten late can cause chaos for your sleep, blood sugar, gut and even your eating habits the next day…

Disrupts your rhythm

If you’re hoping for a good night’s rest, put the ice cream away. Late night snacking could throw off your sleep cycle.

Dr Schenker explains: “Your body’s internal clock, known as the circadian rhythm, is a 24-hour natural cycle that pretty much controls when you feel awake, tired and hungry.”

Part of how it does this is through hormones.

“In the evening, your body releases a sleep hormone called melatonin which helps you to feel tired, whereas in the morning it drops and the stress hormone cortisol rises to wake you up,” adds Dr Schenker.

Your circadian rhythm is influenced by lots of things, with light being the strongest cue, which is why you naturally feel sleepy when it’s dark. But meal timings also play a role.

“Snacking late can suppress the release of melatonin,” says Dr Schenker. “This disrupts your natural circadian rhythm as your body may be used to eating earlier, so eating late can shift circadian timings, potentially making it harder to fall asleep. It may also reduce the amount of quality sleep you get, known as REM sleep.”

There’s science to back this up. Research in the British Journal of Nutrition found that people who ate within one hour of going to bed actually ended up sleeping longer, however they were much more likely to wake up during the night and stay awake for longer. So you may get more hours in bed, but the quality of those hours could be mixed.

Dr Schenker recommends leaving around three hours between eating and bed, to allow digestion to complete.

Over the long term, disrupting your circadian rhythm with late night snacking could have more serious consequences. A research review in the Physical Activity and Nutrition found that ongoing circadian misalignment raises the risk of conditions such as type 2 diabetes, heart disease and obesity.

Gut flare-ups

Your digestive system isn’t designed to keep working late into the night, so with a naturally slower digestion, you might find yourself with indigestion, acid reflux, bloating and IBS-type symptoms, as food doesn’t clear out of the stomach as quickly as it usually would.

“For anyone with a sensitive gut, this is only exacerbated and you can end up nursing a sore stomach, which isn’t what you want right before bed,” says nutritionist Rob Hobson.

“Lying down too soon after eating can allow stomach acid to travel upwards, increasing the risk of heartburn. This is particularly likely if your evening snacks are high in fat, which slows digestion. Sleeping on your left-hand side can help reduce reflux, as it keeps the stomach positioned below the oesophagus and limits acid movement overnight.”

Woman making a heart shape with her hands over her stomach

Makes you eat MORE tomorrow

Next-day hunger caused by late-night snacking often comes down to blood sugar.

What happens with your blood sugar won’t just wreck your sleep, but it can make you ravenous the next day too.

“Blood sugar is the amount of glucose (sugar) circulating in your bloodstream; it’s your brain's main source of energy. Every time you eat, especially carbohydrates, your blood sugar rises and your body releases the hormone insulin to help move that sugar into your cells to be used for fuel,” explains Dr Schenker.

The problem is that blood sugar doesn’t rise and fall evenly; it depends on what you eat.

“Sugary snacks (think pastries, ice cream, cakes and chocolate) make your blood sugar rise quickly (spike) and then fall quickly (crash) whereas more complex carbs, such as oats and wholegrains, balanced with protein cause a slower rise and fall,” explains Dr Schenker.

“The spikes and crashes can disrupt your hunger and fullness hormones so you feel hungry again soon after eating. If this happens late at night, it can affect sleep quality, so you feel tired the next day.”

If you’ve ever had a poor night’s sleep, you’ll likely know the feeling of ravenous hunger that follows you around all day.

It’s because poor sleep is renowned for disrupting appetite hormones, lowering leptin (which signals fullness) and increasing ghrelin (which stimulates hunger).

Late-night snacking makes this effect worse, according to Dr Schenker.

Normally your leptin levels rise during the night while ghrelin rises during the day, particularly before mealtimes. Eating late interferes with this rhythm, leading to higher ghrelin levels the next day.

“This can leave you craving carbohydrates and quick energy the following day.”

A study published in the journal Cell Metabolism suggests this hunger could continue for up to 24 hours.

The safe late-night snacks

For a lot of us, snacking after dinner has become a ritual. But with evening eats potentially causing so much disruption, it’s worth trying to break the habit.

“First, establish if you are really hungry,” says Dr Schenker. “Are you maybe mildly dehydrated? Have a mint tea and see how you feel.”

Perhaps it’s a reward at the end of your day? “In that instance, do something else like take a warm bath to reward yourself,” suggests Dr Schenker. This will have the added benefit of helping your sleep.

“If you really do feel hungry go for snacks that are light and easy to digest.”

Try including foods that contain the amino acid tryptophan, which helps your body make melatonin and serotonin, a neurotransmitter that helps with sleep and mood.

“Dairy products are a good source and easy to digest. Pair with complex carbs to help the tryptophan convert to these hormones in the brain,” says Dr Schenker. Go for Greek yogurt with banana, oats with milk or oat biscuits with cottage cheese. Check out our healthy snacks recipes for more nourishing options.

If you really can’t resist the urge to eat, ask yourself if dinner is actually filling you up.

“Your dinner needs to be big enough to fuel you and it needs to be balanced too to fill you up,” says Rob. “Aim to have a source of protein (such as chicken, fish, beef, tofu), complex carbs (such as brown rice, quinoa), healthy fats (such as avocado, nuts and olive oil) and plenty of colourful vegetables.

“If you’re giving your body the nutrients it needs, you may find that your urge to snack naturally reduces.”