How the Gut-Brain Connection Affects Your Mood

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Has anyone ever told you that you seem "hangry?" If the word isn't familiar to you, the sensation associated with it probably is.

Can you remember a day when you skipped breakfast, only to overreact to a coworker or snap at your kids before lunch? It's possible that you were having a bad day, but if you hadn't eaten in a while, you were probably just hangry.

Hangry: Definition and Symptoms

So where does the word "hangry" come from? As you might have guessed, it's a combination of the words hungry and angry. Hangry isn't exactly a medical term, but that doesn't mean scientists don't recognize its symptoms.

The connection between hunger and mood is evidenced by blood sugar fluctuations. After eating, blood sugar levels increase, giving us a boost of energy. The food we consume is metabolized into glucose, a form of sugar which is your brain's preferred energy source. If you haven't eaten in a while, your blood glucose levels will go down. For most people, this triggers hunger.

Low blood sugar levels and changes in mood are often linked. The following adjectives may describe how you feel when you're hungry:

  • Aggressive: When you get hangry, you may feel the urge to lash out at friends or loved ones. A study of married couples found that intimate partners were more likely to express aggressive impulses towards each other when their blood sugar levels were lower than normal.
  • Distractable: Low blood sugar is associated with poor concentration. Hangry students may have a harder time paying attention in class, and hangry employees might not be able to focus during a pre-lunch meeting or an important phone call at the end of a long day.
  • Impulsive: Sticking to a balanced eating plan can be tough when you're hangry. Studies have demonstrated that mild hypoglycemia (low blood sugar) triggers a hankering for high-calorie foods in the brain.

Your symptoms of being hangry may vary. Some people get tired. Others become agitated. Mental fogginess and a dip in motivation are common. Regardless of your symptoms, it's helpful to recognize when hunger is impacting how you feel.

The Gut-Brain Connection

When we routinely practice good nutrition, we supply our brain with the nutrients needed to function. Unfortunately, hectic schedules and daily stressors can get in the way of eating well. Going too long without food causes additional changes aside from low blood glucose.

"Low blood sugar is the trigger but there are many physiological factors at play," says William Yancy, MD, associate professor of medicine at Duke University School of Medicine and program director at the Duke Diet and Fitness Center.

Dr. Yancy explains that the blood glucose response may be different from person to person. True low blood sugar is a condition called hypoglycemia.

Hypoglycemia is defined as a glucose level lower than 70 milligrams per deciliter (mg/dL).

Dr. Yancy explains that blood sugar fluctuations can feel like hypoglycemia for people who are used to chronically high numbers. When blood sugar drops, the hormones glucagon and epinephrine (also called adrenaline) are released by the sympathetic nervous system (SNS).

This leads to symptoms like:

  • Dry mouth
  • Nervousness
  • Pallor
  • Shakiness
  • Sweating

Glucagon and epinephrine strive to bring blood sugar levels back to normal by breaking down stored carbohydrate or body fat to release stored energy. For this reason, epinephrine has a reputation as a "stress hormone."

Dr. Yancy notes that hunger, sweating, and tingling are caused by an acetylcholine release in the sympathetic nervous system. He adds that the central nervous system may also be involved in the process.

When the central nervous system lacks glucose, it can lead to confusion, irritability, and even decreased consciousness in severe cases. Dr. Yancy adds that there are other hormones involved, such as cortisol and growth hormone, but they play a lesser role.

Sound complicated? Registered dietitian and nutrition expert Molly Cleary breaks it down into simple terms. She explains how our brains get fuzzy when starved for glucose, leading to impulse decisions or a short temper.

"When our blood sugar gets low, it also triggers hormones to be secreted from other organs in our bodies. Some of these hormones play a role in behavior control, and their secretion can make us more aggressive."

Cleary adds that certain people are more prone to getting hangry based on their genetic make-up and communication style. While these physical changes may sound dramatic and potentially dangerous, in most cases they are not.

According to Dr. Yancy: "Severe cases of hypoglycemia only occur in patients taking insulin or sulfonylurea medications for diabetes. In patients who do not take these medications, our physiology will pull us out of the episode."

How to Avoid Getting Hangry

Even if the condition isn't dangerous, most of us would like to avoid getting hangry. After all, who wants to deal with the fallout of snapping at the boss simply because of a missed meal?

Luckily, there are ways to prevent this issue such as:

  • Eating a balanced mix of carbohydrate, protein, and fat
  • Snacking on something small before you feel hangry

Creating Balanced Meals

Cleary explains, "High carbohydrate meals or snacks such as chips, cookies, or candy can raise our blood glucose levels quickly, but then they may cause crashes later. It's best to choose a more balanced option that contains complex carbs and protein.

For balanced snack ideas, Cleary suggests:

Lastly, if you get hangry often, plan your meals when the symptoms are likely to happen. And avoid drinking too much caffeine, advises Dr. Yancy. Caffeine can exacerbate the symptoms, so it's best not to rely on coffee alone to boost your energy levels.

A Word From Verywell

There is nothing more frustrating than losing control of your emotions. Understanding the gut-brain connection may help you to prevent episodes of anger. If you get hangry often, change your meal schedule to avoid hunger or carry healthy snacks to keep your blood sugar steady.

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