How bad is it really to eat sugar before bed?

Eating sugar before bed can lead to weight gain and trouble sleeping.

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Many people enjoy dessert after dinner. There’s something satisfying about chasing a salty meal with something sweet. Learned behaviors, like enjoying a bowl of ice cream in the evening, can also fuel your urge to snack on sugar before bed.

The general dangers of added sugars are well known, but you might be wondering exactly how eating sugar before bed affects your body, especially when it comes to sleep.

To find out, we enlisted doctors and registered dietitians to find out the truth. Whether it’s a bowl of sugary cereal, a cup of sweet tea, or a candy bar at night, here’s what can happen if you eat sugar before bed.

1. It can cause inflammation

Eating a lot of sugar is strongly associated with chronic inflammation, which is linked to a number of health problems like heart disease, obesity, cancer and diabetes, for example. Harvard Health Publishing.

And triggering an inflammatory response in your body might be the last thing you want to do before you hit the hay. The inflammation is linked to sleep apnea, a condition in which inflamed airways obstruct your breathing during sleep, according to the Michigan Center for ATM and Sleep Wellness.

“Sugar can cause inflammation of the tissues lining the mouth and throat, causing swelling and increased mucus production,” says the neurologist and sleep physician. Brandon R. Peters, MD, FAASM. “It can cause postnasal drip and affect breathing, causing snoring and worsening sleep apnea.”

Snoring and sleep disturbances may seem harmless, but they should be taken seriously, according to the Mayo Clinic.

2. It can affect sleep quality

Although many people believe that eating sugar before bed prevents you from sleeping and leads to hyperactivity, there is little evidence to suggest this is actually true.

That said, refined sugars raise blood sugar quickly, which could cause you to feel a rush of energy and make it difficult to fall asleep, Peters says.

“Eating a lot of sugar before bed can cause you to have lighter, less restful sleep with more awakenings,” Peters says. “An arousal is an awakening or a transition from deep sleep to lighter sleep. Frequent awakenings can affect sleep quality and may be linked to breathing problems.”

Although research on eating sweets right before bed is sparse, what we do know for sure is that, in general, overeating affects sleep. A diet high in sugar has been linked to poor sleep quality and duration, according to an August 2019 study in the American Journal of Lifestyle Medicine.


Many sugary drinks like sodas also contain caffeine, which can affect your sleep if taken before bed, according to the ​American Journal of Lifestyle Medicinestudy.

If you have trouble sleeping, limit caffeinated beverages to daytime hours – ideally six hours before bedtime, depending on the Sleep Foundation.

3. It could lead to weight gain

Again, there is little research on how consuming sugar right before bed affects your weight. But we know that excess sugar is stored in fat cells, and eating too much in one sitting can cause fat cells to grow, according to the Cleveland Clinic.

We also know that while you are awake your body may be able to use this sugar for energy. But at night, when you do little or no physical activity, having too much sugar can be problematic.

“When we eat sugar before bed, we don’t metabolize the sugar properly and it becomes inflammatory,” says a dietitian. Dana Ellis Hunnes PhD, RD. “At night when we sleep, we don’t burn that sugar, so it’s more likely to lead to fat storage and weight gain.”

Eating sugary foods earlier in the day gives you the opportunity to metabolize sugar so that it is used for energy rather than stored as fat.


We consider a food high in sugar if it contains 10 grams or more per serving.

So how bad is it really to eat sugar before bed?

If you do it all the time, eating sugar before bed can affect your health. While it’s always a good idea to practice moderation, it may be best to avoid sugar before bed and enjoy your treats during the daytime hours when you’re more active.

“Sugar can act as an inflammatory that disrupts sleep, so it’s best to avoid it as much as possible near bedtime. As a general rule, I recommend someone stay away from sugar for 2-3 hours before bedtime to allow for proper digestion,” says Peters. “That being said, the occasional sugary snack at night probably isn’t something you need to worry about.”

Reducing added sugars in your diet, even in small amounts, can do wonders for your health and sleep. Aim for a maximum of 6 to 9 tablespoons of added sugar per day, depending on the American Heart Association. You may sleep better with this.

Rachel J. Bradford