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Just How Bad Is It to Eat Before Bed?

Researchers take a close and dispassionate look at what happens when we consume food late at night.
Woman eating pizza and drinking soda
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It was always my understanding that eating too soon before bed was a prescription for weight gain. Then again, I probably absorbed this information from the same brain trust that told me that eating before swimming was dangerous, cracking my knuckles would give me arthritis, and that I’d almost certainly “catch my death” if I left the house with wet hair. In recent years however, researchers have taken a close and dispassionate look at what happens when we consume food late at night and found that the answer to the question at the top of this page isn’t that black and white.


When eating before bed goes right…

…it can stabilize morning blood sugar levels

When you wake, your liver gets to work producing extra glucose to give you the energy you’ll need to get up and out of bed. Ordinarily, that jolt of glucose is sufficient to get us going—even it’s only as far at the coffee pot. Some people—particularly those with diabetes—experience nocturnal hypoglycemia or low blood sugar during the night however. This can disrupt sleep, and leave people feeling groggy and/or ravenous upon waking. A few studies have suggested that a snack before bedtime may help prevent these changes in blood sugar by providing a little extra energy to help get you through the night and up and at ‘em in the morning.

“It's really more about what you're eating versus when," says Niket Sonpal, a New York City-based gastroenterologist and professor of clinical medicine at Touro College. Sonpal tells me that eating a large dinner right before bed can negatively affect cardiovascular health and lead to weight gain, while smaller amounts of nutrient-dense food have been shown to be beneficial for maintaining a healthy weight. “Having a small, clean meal before bed can help regulate blood sugar levels that, for some, drop through the night, which leads to feeling very hungry in the morning,” he says. “Lean protein, fresh fruit, vegetable, or a handful of nuts is a great evening option before bed."


…and boost metabolism

A study from Florida State University showed that fit college-age men who consumed a 150-calorie carb- and protein-rich shake 30 to 60 minutes before bed increased their metabolic rate. When researchers did the same experiment with young obese women, they saw improvements in blood pressure and metabolic function.

"If you exercise regularly, eating some small portions before bed can ramp up morning metabolism,” Sonpal says. He suggests protein-rich foods because they may help aid muscle repair overnight.

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Sonpal also cites a small study from the National Institutes of Health (NIH) that found that participants who had daily doses of grapefruit or grapefruit extract exhibited a healthier insulin response—which is strongly tied to metabolic function—compared to participants who were given placebos. “If you like a pre-bed snack, try eating grapefruit for a refreshing and metabolism-boosting treat.”

When eating before bed goes wrong…

…it can be the stuff of nightmares

If you’ve ever had acid reflux—also known as Gastroesophageal reflux disease (GERD) or heartburn—you’ll know that it’s the opposite of a good time. Eating too close to bedtime can increase the likelihood of acid reflux particularly when heavier foods are consumed. “It takes a few hours for the stomach to empty a full meal,” Sonpal says, adding that eating too much, too close to bedtime allows for stomach acid to spill out of a full stomach and into the esophagus which is what causes the acid reflux.”


A 2005 study looked at the relationship between acid reflux and the time between when people eat and when they go to bed and found that shorter dinner-to-bedtime—less than three hours—was significantly associated with an increased acid reflux.

Symptoms of acid reflux—which affects up to 40 percent of Western populations—include difficulty swallowing, the feeling of having a lump in the throat, and exacerbated nighttime asthma. If you think that sounds like a nightmare, you should know that eating before bed may increase the likelihood of you experiencing actual nightmares too. In 2015, researchers in Canada found that 18 percent of study participants reported that eating before bed impacted their dreams describing them as disturbing.

…and mess with weight loss goals

A small 2013 study found that overweight and obese women on a 20-week weight loss program dropped pounds at a different rate depending on whether they ate their major meal before or after 3 pm—this was despite the amount they ate, slept and exercised being exactly the same.

“This is the first study to show that eating later in the day…makes people lose less weight, and lose it slower,” says the study’s lead author, Marta Garaulet, a professor of physiology at the University of Murcia in Spain.

Garaulet conducted a second study of healthy women the following year, and showed that when participants ate a big lunch after 4:30 pm, they burned fewer calories while resting and digesting their food than they did when they ate at 1 pm—even though the calories consumed and level of activity was the same.

In conclusion: Whether eating before bed is a good or bad idea is really about what you’re trying to address. If GERD, disturbing dreams, or an inability to lose weight are vexing you, putting three hours between your last mouthful of food and your head hitting the pillow is certainly worth a try. If, on the other hand, you tend to wake up feeling groggy, cranky and/or want to up the intensity of your morning workouts, a small, nutrient-dense nosh in the hour before you hit the sack could better set you up for the day.

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