If you’ve ever woken up in a pile of junk food wrappers—or just, you know, overdone it on Halloween candy in a less dramatic fashion—you may be familiar with the feeling of a sugar hangover. The unpleasantness you’re left with several hours after going all in on sweets (headache, fatigue, shakiness, general crappiness) can feel eerily like a booze-induced hangover. But what causes this cascade of awful symptoms? We spoke with a few experts to find out.
When you eat food, especially carbohydrates like sugar, your body acts quickly to keep your blood sugar at a normal level.
Unless you have a health condition like type 1 or type 2 diabetes, your body typically does a pretty great job of regulating your blood sugar, which is the concentration of glucose in your blood. Glucose serves as your body’s main source of energy, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) explains, so keeping it in the right balance is important.
So, let’s say you eat some carbohydrates. In response, your pancreas secretes a hormone called insulin into your bloodstream to break down those carbs for energy, endocrinologist Clare Jung Eun Lee, M.D., an assistant professor of medicine at the Johns Hopkins University School of Medicine, tells SELF. This keeps the level of sugar in your blood within a normal range. (We’ll dive into how diabetes can influence this process in a bit.)
When the opposite problem occurs—your blood sugar drops due to too much energy expenditure (exercise) and/or not enough fuel (food)—your liver releases glucose it has stored for this very purpose, the Mayo Clinic explains. This helps maintain your blood sugar even when you’re running on fumes.
Consuming a high concentration of simple carbohydrates (like candy) can cause a more rapid and dramatic uptick in blood sugar than complex carbs (like brown rice).
“The extent to which your blood sugar is [changing] is different than if you were to have a well-balanced meal,” Dr. Lee explains. A well-balanced meal contains complex carbohydrates like whole-wheat products, which your body breaks down more gradually, as well as protein and fat to further slow that carbohydrate absorption.
Even if you devour a ton of simple sugars, your blood sugar should stay in a technically normal range because your pancreas will produce insulin to help convert it into energy. But, Dr. Lee explains, “You will still have a relatively large flux in your glucose.” Soon after eating a lot of sugar, you may feel an initial jolt of energy, especially if your blood sugar was on the low side before eating. After that, though, you may feel the start of that “sugar hangover” thanks to modest symptoms of high blood sugar, or hyperglycemia, such as fatigue, headache, and increased thirst, according to the Mayo Clinic. If you don’t have a condition like diabetes, the symptoms shouldn’t be severe and won’t be dangerous to your health. They just won’t feel great.
The “hangover” sensation really comes into play a few hours after you eat all that sugar, when the insulin your pancreas secreted after you ate causes a blood sugar dip.
While your pancreas usually gets it right, it can overcompensate. “Sometimes after a very high-sugar meal or beverage, an exaggerated amount of insulin is released to accommodate this sugar load,” Mary Vouyiouklis Kellis, M.D., an endocrinologist at Cleveland Clinic, tells SELF. Several hours later, as this insulin peaks, your blood glucose will start falling quickly. “You can get a ‘crash and burn’ effect,” Dr. Kellis says. “This phenomenon is known as reactive hypoglycemia.”
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It’s no secret that sugar can cause issues if you’re indulging in a little too much of the sweet stuff. Still, most Americans are eating too much sugar.
The harmful effects it can have on your physical health are well studied, which is why we talk so much about reducing sugar intake to lower the risk of these effects, like chronic disease.
While ditching the sweet stuff can result in a physically healthier you, it’s the effect sugar has on our mental health that’s worth taking a second look.
You’ve probably heard of the term “sugar rush” — and have maybe even turned to a doughnut or soda for an extra boost during a long day.
Yet sugar may not be such a positive pick-me-up after all. Recent research indicates that sugary treats have no positive effect on mood.
In fact, sugar may have the opposite effect over time.
One study published in 2017 found that consuming a diet high in sugar can increase the chances of incident mood disorders in men, and recurrent mood disorders in both men and women.
A more recent 2019 study found that regular consumption of saturated fats and added sugars were related to higher feelings of anxiety in adults over age 60.
Although more studies are needed to solidify the relationship between mood and sugar consumption, it’s important to consider how diet and lifestyle choices can affect your psychological well-being.
If your idea of coping with stress involves a pint of Ben and Jerry’s, you’re not alone. Lots of people turn to sugary sweets when they feel anxious.
That’s because sugary foods can weaken the body’s ability to respond to stress.
Sugar can help you feel less frazzled by suppressing the hypothalamic pituitary adrenal (HPA) axis in your brain, which controls your response to stress.
Researchers at the University of California, Davis found that sugar inhibited stress-induced cortisol secretion in healthy female participants, minimizing feelings of anxiety and tension. Cortisol is known as the stress hormone.
Yet the temporary relief sweets provide may make you more reliant on sugar, and raise the risk of obesity and its related diseases.
The study was limited to just 19 female participants, but results were consistent with other studies that have looked at the connection between sugar and anxiety in rats.
While findings show a definite link between sugar intake and anxiety, researchers would like to see more studies done on humans.
It’s hard to avoid reaching for comfort foods, especially after a difficult day.
But the cycle of consuming sugar to manage your emotions may only make your feelings of sadness, fatigue, or hopelessness worse.
Multiple studies have found a link between diets high in sugar and depression.
Overconsumption of sugar triggers imbalances in certain brain chemicals. These imbalances can lead to depression and may even increase the long-term risk of developing a mental health disorder in some people.
In fact, a 2017 study found that men who consumed a high amount of sugar (67 grams or more each day) were 23 percent more likely to receive a diagnosis of clinical depression within 5 years.
Even though the study just involved men, the link between sugar and depression is also found in women.
Quitting processed sugar might not be as simple as you think.
Withdrawing from sugar can actually cause side effects, such as:
- anxiety
- irritability
- confusion
- fatigue
This has led experts to look at how the withdrawal symptoms from sugar can resemble those of certain addictive substances.
“Evidence in the literature shows substantial parallels and overlap between drugs of abuse and sugar,” explains Dr. Uma Naidoo, who’s considered the mood-food expert at Harvard Medical School.
When someone misuses a substance for a period of time, like cocaine, their body goes into a physiological state of withdrawal when they stop using it.
Naidoo says that people who are consuming high amounts of sugar in their diets can similarly experience the physiological sensation of withdrawal if they suddenly stop consuming sugar.
That’s why going cold turkey from sugar may not be the best solution for someone who also has anxiety.
“Suddenly stopping sugar intake can mimic withdrawal and feel like a panic attack,” Naidoo says. And if you have an anxiety disorder, this experience of withdrawal can be heightened.
Your stomach may be telling you to dive in and drink your way out of that jumbo cherry Icee, but your brain has a different idea.
Emerging research has found that diets high in sugar can impair cognitive functioning, even in the absence of extreme weight gain or excessive energy intake.
A 2015 study found that consuming high levels of sugar-sweetened beverages impaired neurocognitive functions like decision making and memory.
Granted, the research was done on rats.
But a more recent study found that healthy volunteers in their 20s scored worse on memory tests and had poorer appetite control after just 7 days of eating a diet high in saturated fat and added sugars.
While more studies are necessary to establish a clearer link between sugar and cognition, it’s worth noting that your diet can affect your brain health.
Just because you’re ditching or limiting processed sugar doesn’t mean you have to deny yourself the pleasure of sweet-tasting food.
In addition to being a doctor known as an expert on food and mood, Naidoo is also a chef and the author of the forthcoming book “This Is Your Brain on Food.”
Here are a few of her favorite low- or no-sugar recipes.
Chef Uma’s Chai Tea Smoothie
Ingredients
- 1 serving vanilla protein powder of your choice
- 1/4 avocado
- 1 tbsp. almond butter
- 1 cup almond milk
- 1/8 tsp. each of ground cinnamon, nutmeg, clove, and cardamom spice
- 1/4 tsp. organic vanilla essence
- ice
- a small bit of organic honey to sweeten, if needed
Optional
- brewed chai tea instead of spices
- avocado for creaminess
Directions
- Add all ingredients to your blender.
- Blend until smooth.
Chef Uma’s Watermelon Pops
Ingredients
- 4 cups chopped watermelon
- 1 tablespoon honey
- juice of 1 lime
- zest of 1 lime
Optional
- 1 cup whole blueberries
Directions
- Puree the watermelon, honey, lime juice, and lime zest in a blender.
- Pour into square ice cube trays or popsicle molds.
- Before fully frozen, add ice cream stick to each ice cube or mold.
- If desired, add whole blueberries to ice cube trays or popsicle molds.
Chef Uma’s Oven-Roasted Sweet Potatoes with Red Miso Paste
Ingredients
- 1/4 cup olive oil
- 1/4 to 1/2 cup red miso paste
- salt and pepper to taste
- 4 medium sweet potatoes
Directions
- Preheat oven to 425ºF (218ºC).
- Create a marinade by mixing the olive oil, red miso paste, and salt and pepper.
- Peel and cut sweet potatoes into equal-sized pieces or discs.
- Toss the sweet potatoes in the marinade.
- Place sweet potatoes on a sheet pan in a single layer.
- Roast for about 20 to 25 minutes, or until potatoes are tender.
Sara Lindberg, BS, MEd, is a freelance health and fitness writer. She holds a Bachelor of Science in exercise science and a master’s degree in counseling. She’s spent her life educating people on the importance of health, wellness, mindset, and mental health. She specializes in the mind-body connection, with a focus on how our mental and emotional well-being impact our physical fitness and health.