How Sugar Affects Sleep & What You Can Do About It

July 14, 2025 By Andy Jacinto

One minute you’re enjoying dessert. The next, you’re staring at the ceiling, wondering why sleep won’t come.

Sugar might be the reason.

Key Takeaways

Does sugar affect sleep? Yes. But with better timing, smart snack swaps, and a sleep-friendly routine, you can enjoy the occasional treat without ruining your rest.
Eating too much sugar, especially late in the day, can lead to restless nights, increased cravings, and disrupted sleep cycles.
Sleep and blood sugar go both ways. Poor sleep makes it harder to manage glucose and can increase your cravings for sugary foods.

So, does sugar affect sleep? Yes, it can.

Eating too much sugar, especially close to bedtime, may lead to restlessness, lighter sleep, and more wake-ups during the night.

In this blog, we’ll look at how sugar affects your brain and body, how it interferes with sleep cycles, and what you can do to avoid those unwanted midnight energy spikes.

Jump to a section:

How Sugar Affects Your Sleep

We often think of sugar as an energy booster. But that boost can come at a cost, especially when you’re trying to get a solid night’s rest.

A 2016 study looking at university students found a clear link between sugar and poor sleep. As the researchers put it, “poor sleep quality was significantly related to higher added sugar intake.” Only 17% of the participants reported getting good sleep.

That’s a big problem, considering how common added sugar has become in daily diets.

Let’s break down how sugar does this.

Poor Sleep Quality

In another 2016 study published in the Journal of Clinical Sleep Medicine, researchers found that “increased intake of both sugar and non-sugar/non-fiber carbohydrates was associated with more nocturnal arousals during sleep.” In other words, sugar may keep your brain too active to settle into proper rest.

Sleep isn’t just about how long you’re in bed. It’s about whether your body moves through a proper sleep cycle. That includes deep sleep, where most of the repair work happens.

Too much sugar can throw that off. It spikes your blood glucose, keeping your brain alert when it should be winding down. It also increases the chance of wake-ups during the night, cutting into those deeper stages of sleep.

You might not link a restless night to a dessert hours earlier, but your body remembers. The more sugar you eat, the harder it may be to reach that deep, restorative phase.

The result? You wake up feeling like you barely slept.

Increased Cravings and Overnight Hunger

Poor sleep doesn’t just leave you tired. It can also send your appetite into overdrive.

As Manse Medical explains, “a lack of sleep will increase appetite, and potentially lead to a significant increase in weight over time.” When you’re low on rest, hunger hormones like ghrelin spike, while leptin (which helps you feel full) drops. The result? You’re more likely to crave sugary, high-calorie foods.

But here’s the catch. Giving in to those cravings, especially late in the day, can make sleep even worse.

Sugar spikes your blood glucose. When it crashes, it can trigger feelings of hunger or restlessness. Some people even wake up hungry in the middle of the night, not realising it’s the sugar cycle repeating itself.

It becomes a loop. Poor sleep leads to cravings. Cravings lead to more sugar. And sugar makes it harder to get the proper sleep your body needs.

Increased Inflammation and Restless Sleep

Too much sugar doesn’t just give you a quick energy spike. It can stir up inflammation in your body, and that can mess with your sleep in ways you might not expect.

High-sugar diets have been linked to raised cholesterol, gut imbalances, and increased inflammatory responses. That inflammation triggers cytokines, which are chemical messengers your body releases when it’s under stress. These can affect how deeply and how long you sleep.

In fact, one study published in the Journal of Current Pharmaceutical Design found that “many of the symptoms induced by sleep loss, e.g., sleepiness, fatigue, poor cognition, enhanced sensitivity to pain, can be elicited by injection of exogenous IL1 or TNF.”

Put simply, your body reacts to inflammation the same way it reacts to sleep deprivation.

Inflammation can also raise your cortisol levels, make you feel more alert than you should be, and cause the kind of discomfort that keeps you tossing and turning. It’s a perfect storm for a restless night.

How Long Before Bed Should You Stop Eating Sugar?

It’s best to avoid added sugar for at least two to three hours before bed. This gives your body time to stabilise blood sugar, digest properly, and start winding down.

You might ask, does sugar before bed affect sleep? The answer is yes. Eating sugar late in the day can keep your energy levels high when they should be slowing down. That spike can delay melatonin release and make it harder to fall or stay asleep.

A 2011 study published in the Journal of Clinical Sleep Medicine found that “food intake near the sleeping period (dinner and late night snack) was negatively associated with sleep quality variables,” especially when the food was “high in calories and fat.”

Even healthy sleepers saw more disrupted rest after eating too close to bedtime. That’s reason enough to rethink dessert as a nightly habit.

If you do need something before sleep, choose a light snack that won’t overload your system. The goal is to avoid the sugar spikes and crashes that interfere with good sleep.

Does sleep affect blood sugar too?

Yes, it does. Sleep isn’t just when your body rests. It’s also when it resets key systems like glucose metabolism and appetite control.

When you don’t get enough sleep, your body becomes less sensitive to insulin. That makes it harder to regulate blood sugar levels, even if you haven’t changed anything about your diet.

As the researchers behind a 2005 study in the Journal of Applied Physiology put it, “short sleep duration may represent a novel risk factor for insulin resistance and Type 2 diabetes.”

Poor sleep also affects hunger hormones. Leptin goes down, ghrelin goes up, and suddenly that mid-morning pastry looks a lot harder to resist.

So if you’ve been cutting back on sugar but still feel off, it could be your sleep getting in the way of better balance.

Tips for Cutting Back Without Going Cold Turkey

Quitting sugar overnight sounds good in theory, but let’s be honest, it rarely works.

The goal isn’t to go full detox. It’s to make sugar less of a daily habit and more of an occasional treat, especially in the hours leading up to bedtime.

Here’s how to cut back without the crash:

1. Cut back on sugar in the evening

Focus on reducing sugar in the second half of your day. Swap dessert for fruit or yoghurt. Trade sweet drinks for herbal tea or night-time detox drinks. Even a small shift can improve how you sleep.

2. Read the sneaky labels

Sugar hides in all sorts of things that don’t even taste sweet, like sauces, breads, and “healthy” snack bars. Take a quick look at ingredient lists and aim to avoid anything with added sugars, especially late in the day.

3. Choose satisfying swaps

Craving something sweet before bed? Go for snacks that keep you full without spiking your blood sugar. The right mix of protein, fibre, and healthy fats can help you feel satisfied and settled.

✅ A banana with a small spoon of peanut butter
✅ Greek yoghurt with a sprinkle of cinnamon
✅ A handful of almonds or walnuts
✅ Wholegrain toast with avocado or hummus
✅ Cottage cheese with sliced kiwi or berries
✅ Warm milk or a caffeine-free chai

These won’t overload your system like chocolate or biscuits might, and they’re less likely to mess with your sleep.

4. Cut back slowly

You don’t have to give up sugar overnight. Start with what you eat in the evening, then work your way backwards. Making small changes gives your body and taste buds time to adjust.

Try avoiding the following foods close to bedtime:

❌ Chocolate and sugary desserts
❌ Caffeinated drinks like coffee, cola, and energy drinks
❌ Foods high in fat, such as fried snacks, full-fat dairy, and fatty meats
❌ Spicy foods that might trigger reflux
❌ Acidic foods like tomatoes and citrus
❌ Alcohol, which can mess with your sleep cycles even if it makes you drowsy

These can all interfere with digestion, energy levels, or hormone release right when your body should be slowing down.

5. Don’t forget the basics

Poor sleep makes you crave more sugar. And eating more sugar makes sleep worse. So support yourself with regular meals, hydration, daylight exposure, and a wind-down routine. It all helps.

Can You Keep Sugar and Still Sleep Well?

Yes, you can. It’s all about balance. Avoiding sugar close to bedtime, watching your cravings, and paying attention to how your body reacts can go a long way.

Still wondering, does sugar affect sleep? It does. But so does your sleep setup. Ecosa’s ergonomic pillows and supportive mattresses are designed to help you fall asleep faster and stay asleep longer. Even if a sweet treat slips in, your bed should still have your back.

References (6)

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