Are sugar hangovers real?
Yes, feeling crummy following a sugar splurge is a real thing. Here’s what’s going on and how to help yourself feel better.
Eating that second doughnut felt like a good idea at the time—but all too quickly, the initial rush of sugar wore off. Now you’re groggy, sluggish, and out of sorts. A headache is starting to creep in, and all you want to do is curl up in bed.
Although cake, cookies, candy, and the like are very different from a stiff cocktail, eating too much sugar can cause your blood glucose levels to go haywire—leading you to experience what sometimes feels like an alcohol-induced hangover.
The good news is the symptoms are typically short-lived. However, in the long term, frequent overindulgence can contribute to serious issues like heart disease, diabetes, and dementia. So you want to be picky about when—or if—you have something full of added sugar. And, when you do, take steps to minimize the conditions that lead to that miserable crash. Here’s what you need to know about sugar hangovers so you can make an informed decision.
What is a sugar hangover?
The phrase “sugar hangover” is informally used to describe the physical effects of eating too much sugar, although over-eating refined carbohydrates like pasta and white bread can have the same effect. A sugar hangover is composed of two states: postprandial hyperglycemia (high blood sugar after eating) followed by reactive hypoglycemia (low blood sugar after the crash). Both states can cause symptoms like headache and brain fog, and putting your body on this rollercoaster can feel disorienting and uncomfortable.
What’s happening in your body during a sugar hangover?
A sugar hangover happens because of changes in blood glucose. Although it’s normal to have some variability in your glucose levels throughout the day, unusually high highs or low lows can cause problems.
When we eat carbohydrates (such as sugar), our body breaks down the food into glucose. When glucose is released into our bloodstream, it raises our blood sugar. In turn, the pancreas starts producing insulin. This hormone moves glucose from the bloodstream into cells by binding to insulin receptors on cell membranes, triggering a series of signals that allow glucose transporters to open and let glucose enter the cells for energy or storage. This process effectively lowers our blood sugar levels.
When glucose soars above normal levels (higher than 140 mg/dL), this is known as postprandial (after eating) hyperglycemia. It can happen when you eat any food high in refined carbohydrates, like sugar or white flour, especially when eaten alone without fiber, proteins, and fats that can slow down digestion. The sugar is quickly digested and absorbed, causing a rapid rise in blood sugar.
After the spike comes the crash—or, in this case, the hangover. Reactive hypoglycemia (when blood glucose dips below 70 mg/dL) typically occurs within four hours of eating. As your body releases a flood of insulin to deal with the excess glucose in your system, it can effectively overshoot, and blood sugar levels can dip too low before eventually returning to baseline. Very low blood glucose can cause shakiness, dizziness, sweating, hunger, fatigue, headache, confusion, irritability, anxiety, and irregular heartbeat.
Why do we feel so bad while riding the sugar wave? Our body has a complex system of hormones and signals designed to keep blood sugar in a healthy range, explains registered dietitian Steph Greunke, MS, RD, CPT. So when blood sugar is high or low, the body introduces counter-regulatory mechanisms, all of which can have side effects that feel like hangover symptoms.
For example, she says you may experience headaches due to lower glucose availability in the brain. Since glucose is the brain’s primary energy source, any disruption in glucose availability can impair normal brain metabolism, the process by which glucose is transported into brain cells and converted into energy (ATP) to support neural activity, cognitive functions, and overall brain health. Additionally, Greunke explains another mechanism meant to return the body to baseline: the release of hormones like adrenaline (epinephrine) and cortisol to stimulate the liver to release stored glucose. But this can also stimulate thirst centers, making you feel thirsty.
Adrenaline may also contribute to a quickening heartbeat, sweating, and a jittery or anxious feeling. Fluid shifts and insufficient glucose levels can cause blurred vision, Greunke says, due to swelling of eye tissue. Hunger can also set in during hypoglycemia as your body craves nutrition to restore blood sugar to a normal range.
Is a sugar hangover dangerous?
The risk of a sugar hangover depends on your health status and the severity of symptoms. For people with diabetes (a condition in which insulin doesn’t function normally or at all), both hyperglycemia and hypoglycemia require immediate attention, as they can be dangerous if left untreated and may lead to diabetic coma, life-threatening dehydration, and seizures.
For others, a sugar hangover will usually resolve itself. “For people with well-controlled metabolic health, the body’s mechanisms will eventually bring low glucose back to a more stable, healthy range,” Greunke explains. However, if you are experiencing severe symptoms, seek medical attention. Many people who have diabetes or prediabetes (the precursor to this disease) don’t know it.
Additionally, repeated sugar spikes and hangover crashes can contribute to health problems down the line. Research shows that chronically high blood glucose levels—often from overconsumption of refined carbs—are connected with an increased risk of obesity and are a risk factor for cardiovascular disease, liver disease, dementia, and certain cancers.
How to prevent or lessen a sugar hangover
“The best way to ‘treat’ a sugar hangover is to work on preventing it from happening as much as possible,” Greunke says. In an ideal world, that means mostly avoiding foods with a lot of added sugars, which add no nutritional value.
But, if you do decide to have some sweets or a pastry, a few strategies may help prevent feeling like you did rounds of shots afterward:
- Save sweets for after a meal: In a small study, starting a meal with protein and fat and ending with sugar or simple carbohydrates (rather than the other way around) helped reduce blood sugar spikes—even when the amount of sugar eaten stayed consistent.
- Skip the alcohol: To avoid being hungover and sugar-hungover, don’t mix sweets with alcohol. One small study following 10 healthy non-diabetic participants found the incidence of reactive hypoglycemia to be much more common after consuming glucose and alcohol (five people) than after consuming glucose alone (one person) or alcohol alone (none of the participants).
- Add fiber: Fiber can slow food digestion and glucose absorption, warding off a blood sugar spike and subsequent crash. Balancing sugar intake with fiber (think: a handful of nuts before your cookie) may help encourage stable glucose.
- Drink water: Blood glucose concentrations can rise when there’s less water in the body, raising the risk of hyperglycemia. Remember to drink fluids throughout the day, but avoid sugary drinks, which can increase blood sugar levels quickly.
- Get active: Research shows that 20 to 60 minutes of aerobic activity starting within 30 minutes after eating can help blunt a rise in glucose. Consider taking a brisk walk following your meal.
If you’re already in the throes of a sugar hangover, the best course of action depends on your health status. People with diabetes who experience symptoms of hyperglycemia (such as vomiting or extreme thirst) or hypoglycemia (such as weakness, altered mental state, or fainting) should seek immediate medical attention.
The most effective way to combat mild hyperglycemia is with exercise—think a long walk or a bike ride. For those experiencing hypoglycemia without diabetes, Greunke says to base your treatment on the severity of your symptoms and current blood sugar levels:
- Mild symptoms and/or blood sugar above 70 mg/dL: “If you’re noticing symptoms, you can usually get by with a balanced snack like a small piece of fruit with nuts or cheese to stabilize your blood sugar,” she says.
- Moderate symptoms and/or blood sugar between 54 and 70 mg/dL: The recommendation is to consume 15 grams of fast-acting carbohydrates (a tablespoon of honey or ½ cup of fruit juice) to get blood sugar back up to a normal range. Wait 15 minutes, recheck your levels, and if they haven’t gone up, consider having another serving of carbs or seeking medical attention.
- Severe symptoms and/or blood sugar lower than 54 mg/dL: Consider seeking medical attention. (Note that several factors can impact a glucose reading. A common one related to low glucose values overnight is pressure on the sensor [i.e., from sleeping on it]. If you see a very low reading but have no symptoms or can’t connect the crash to a recent meal, note it could be a sensor issue.)
Sugar hangovers remind us how sensitive our bodies can be to glucose highs and lows. But by implementing daily healthy habits and maintaining stable blood sugar, you can enjoy occasional treats without feeling like you just took a line of shots.
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