Hunger is the cue your body sends to your brain when you’re in need of sustenance. But this cue can be influenced by a variety of things, so you may not actually need the calories you think you do. What can impact the way your body lets you know you’re hungry – and how can you tell if you’re actually in need of food?

1. Sleep deprivation

Sleep plays a vital role in health, influencing things like hormone regulation and memory. But did you know that sleep deprivation can lead to increased feelings of hunger? Lack of sleep affects the way you eat and foods you crave. Hunger is controlled by two hormones, leptin and ghrelin. Leptin is a hormone stored in fat cells that tells you when you’re full, while ghrelin, known as the hunger hormone, tells your body that you’re hungry.

“Sleeping fewer than six hours per night triggers the area of your brain that increases your need for food,” says Armaghan Azad, MD, a lifestyle medicine physician and IIN Health Coach. “When the level of ghrelin spikes and the level of leptin falls, it creates a vicious cycle of hunger that leads to cravings and blood sugar spikes. This cycle not only causes you to store fat and gain weight but ultimately leads to the development of obesity, prediabetes, type 2 diabetes, high blood pressure, and chronic inflammation.”

2. Stress

While occasional elevated levels of stress come with normal life, extended periods of stress can wreak havoc on the body. Stress is a normal bodily response to stressful situations and activates our fight or flight response. When this happens, the hormone cortisol floods our bodies. During periods of stress, the body prepares itself with enough sugar or energy to ensure survival. Insulin levels fall, epinephrine levels rise, and more glucose is released from the liver. At the same time, cortisol levels rise, which causes your body to become less sensitive to insulin. As a result, more glucose is available in the bloodstream and over time leads to feelings of constant hunger and weight gain.

3. Liquid calories

Drinking your calories instead of eating them can lead to feelings of hunger. It makes sense – your stomach sends signals to your brain when it’s full of food, which takes time to digest. You won’t feel hungry again until that food has moved through your stomach and into the rest of your digestive system. But if you drink your calories (think smoothies, shakes, thin soups, or juices), you digest those foods much more quickly than a hearty meal, like oatmeal. So while you still may be consuming the right number of calories for peak nutrition, you won’t feel full and may consume extra calories to satiate that feeling.

4. Lack of fiber

Making sure you have a good mix of vitamins and minerals in your diet is key to a healthy digestive system. Fiber is important to consider and helps you feel full after eating. The typical American diet is full of refined carbohydrates, which have been processed and stripped of their fiber, vitamins, and minerals. White flour is a source of refined carbs and used in most bread and pasta options. Soda, candy, and foods made with high-fructose syrups and sugars are also considered refined carbs.

Since these lack fiber, your body digests them very quickly. Consuming a lot of refined carbohydrates leads to feelings of hunger, even after meals. Though bread and pasta may not have much fiber, these five foods do.

5. Hyperthyroidism

Hyperthyroidism (not to be confused with hypothyroidism) is a condition where your body makes more thyroid hormone than it needs to function. The hormones that are created in your thyroid help regulate your metabolism. When you have an overactive thyroid, your metabolism works overtime, and people who have hyperthyroidism often experience otherwise unexplained weight loss and a constant feeling of hunger.

6. Breastfeeding

Sheri Vettel, RDN, explains, “Breastfeeding can burn around 500–600 calories per day.” This is roughly the equivalent of going for a five-mile run each day! It’s important for breastfeeding parents to make up the calories they’re expending breastfeeding. Vettel recommends replacing these calories with easy, quick, healthy snacks, like homemade trail mix.

7. Low blood sugar

Like high blood sugar levels, low blood sugar levels can also lead to feelings of hunger. Eating food – any food – naturally raises blood sugar levels, though foods high in carbohydrates and sugar raise blood sugar levels more than others. Low blood sugar causes your body to release stress hormones, like epinephrine, which is responsible for the warning signs of low blood sugar, such as tremors and feelings of hunger.

8. Distracted eating

We all know how easy it is to lose focus and eat while distracted, especially when working or taking care of children. New research shows just how distracted eating impacts what and how much food we eat. In a 2020 study, researchers found that “when distracted, healthy, young adults consumed significantly less food and their memory of the meal was dampened.” This resulted in overall fewer calories consumed as well as continued feelings of hunger in participants.

9. Leptin resistance

We mentioned that leptin is the hormone that controls feelings of fullness and thus decreases appetite and helps control weight. Some people are resistant to leptin, which can cause weight gain and even result in obesity. Leptin resistance can also occur due to hormonal fluctuations caused by obesity or other metabolic conditions. People with leptin resistance may never feel full, so they have a very difficult time eating the right number of calories.

10. Medication

Certain medications can increase feelings of hunger – and result in weight gain. Some medications that have this side effect include antidepressants and antipsychotics, corticosteroids, insulin, epilepsy medications, beta-blockers, and opioids. The reason for increased feelings of hunger from these medications vary, but many of the medications impact your hormones. Throwing off any one hormone can cause a chain reaction that results in changes in your body. For example, with corticosteroids, your metabolism is altered, which also impacts your electrolyte balance and hydration levels. This can leave you feeling hungry and tired and less likely to find the motivation to exercise.

11. Dehydration

If you’re feeling hungry between meals, you may actually just be thirsty. Drinking enough water is important to wellness in every part of your body, including brain health, heart health, a regular digestive system, and healthy skin. Besides feeling hungry, dehydration can lead to dizziness, muscle cramps, and feelings of anxiety and depression. If you’re feeling hungry, try drinking a large glass of water first. Tired of drinking plain water to stay hydrated? Check out these easy ways to drink more water.

The bottom line

There are many reasons you may feel hungry all the time – most commonly because you are hungry! Hunger is often a clue that you need nutrients, so listen to your body! If these feelings are constant or if they arise between your normal mealtimes, consult your doctor to make sure there’s no underlying medical cause. Otherwise, choosing healthy food options and drinking plenty of water are great ways to satisfy your appetite.