Have you ever guzzled a tall glass of water right before bed and then had to get up to use the bathroom in the middle of the night? Struggled to doze off after having an after-dinner espresso, or had a terrible night’s sleep after sipping a few too many late-night cocktails?
Drinking enough liquids each day is crucial to staying hydrated, but when you drink different types of beverages throughout the day matters. Drink too much of anything too late, and it could affect your sleep.
Amy Bragagnini, a spokesperson for the US Academy of Nutrition and Dietetics, says dieticians constantly counsel patients on how to get enough fluids— which is 15.5 cups a day for men and 11.5 cups for women, something most people don’t achieve. A key part of that is discussing the timing of drinking liquids, so she often asks her patients: “What time do you typically go to bed?”
“The answer to this helps us provide information that will not only help patients meet their fluid goals but will also set them up for a good night’s sleep,” she said. “We realise not everyone works a typical 8am to 5pm job and goes to bed around 10pm.”
Drinking too much of any kind of fluid before bed can affect your sleep cycle, Bragagnini says. A good night’s sleep is crucial for reducing your risk for obesity, heart disease, stroke, depression, and your overall mood and ability to function each day.
It’s a good idea to understand the role that what you drink (and when) plays in sleeping well. Bragagnini urges her patients to stop drinking most fluids at least two hours before bed, but the best time frame depends on what you’re drinking. Here’s a closer look at when to stop drinking different types of beverages and why adhering to these cutoff times will help you get a good night’s sleep.
Caffeinated drinks
It may be tempting to drink coffee or another caffeinated beverage to get through a sleepy afternoon. But the later you drink caffeine, the more it can affect your sleep. Having more than 400mg of caffeine a day – the equivalent of about four regular cups of coffee – can cause restlessness, dehydration, anxiety and insomnia.
To get a good night’s sleep, research suggests it’s a good idea to stop drinking caffeine at least six hours before bed, says Chris Winter, sleep expert, neurologist and adviser for Somnox.
“Caffeine can act as a stimulant, which can disrupt the depth of sleep and affect how long one stays asleep,” Bragagnini says.
Alcoholic beverages
A glass of wine or beer close to bedtime might make you feel sleepy, but it can actually disrupt your sleep. That’s because alcohol can have both sedative and stimulative effects on the body.
“It may initially help someone fall asleep but eventually the sedative effect will wear off, and many people have a hard time falling back to sleep after waking up,” Bragagnini says.
Drinking alcohol in the evenings can disrupt your rapid eye movement (REM) sleep cycle, which is the deepest sleep stage, she explained. It may also cause vivid or scary dreams, interrupt consistent breathing patterns during the night, and lower your inhibitions, which might lead to snacking on unhealthy foods right before bed.
Making your last call four to five hours before going to sleep is your best bet, Winter said. This is about how long it takes most people to metabolise alcohol, which also depends on your size and weight, how much you drink, and how often you drink.
Juice and other sugary drinks
Drinking too many sugary beverages before bed isn’t recommended, Bragagnini says. Consuming sweetened drinks, like sodas or juice, in the evening will raise your blood sugar, which triggers your pancreas to release insulin, a hormone that allows glucose into your cells to provide energy.
This sugar rush could keep you up at night. So, it’s best to avoid sugary drinks at least two hours before bedtime.
Consuming too much sugar – more than nine teaspoons a day for men and six for women – at any time of day can increase your risk of insulin resistance, which raises your risk for diseases like cancer and diabetes.
Dairy
You’ve probably heard that drinking a glass of warm milk before bed can help you sleep. Some research suggests that a mix of milk and honey could improve sleep and that drinking milk could help older people fall asleep. Milk also contains tryptophan, an amino acid known to cause drowsiness.
“The research on the benefits of drinking milk before bed is limited,” Bragagnini says. “Some researchers urge caution about consuming dairy products before bed.”
Consuming dairy before bed could increase the likelihood of gastroesophageal reflux disease (GERD), which causes acid from the stomach to flow into the esophagus causing acid reflux, she said.
Cutting out dairy at least two hours before bed is a good option for most people – though if you swear that a cup of warm milk helps you drift off to sleep, there’s likely no harm in it. Just make sure you brush your teeth afterward, as the sugar in dairy could cause cavities if it’s left on your teeth, Winter says.
Water
Drinking water throughout the day helps you avoid dehydration at bedtime. Water should also be your beverage of choice before bed. Janice Johnston, chief medical officer at Redirect Health, says water keeps you hydrated and regulates your body temperature through the night, which helps you sleep better.
“Additionally, when people are suffering from anxiety or even a head cold, hot water before bed can be soothing and can clear congestion,” she said.
Keeping a water bottle on your nightstand is a good idea if you often wake up with a dry mouth, Bragagnini says. Johnston suggested drinking water right after waking up in the morning to rehydrate the body after sleep.
Any liquids – if you don’t want to get up to pee in the night
The only downside to drinking water right up until bedtime is that you might need to get up to use the bathroom during the night. Winter said middle-of-the-night bathroom breaks usually won’t degrade your sleep too much, though.
“The NBA players who I work with hydrate aggressively and often wake up to go to the bathroom,” he says. “No issues.”
The Cleveland Clinic suggests avoiding liquids at least two hours before bed, if you don’t want to get up in the middle of the night. Depending on the person, it can take a few minutes to an hour or two to need to pee after drinking.
