It’s no surprise that our appetite changes during certain phases of life (ah, to be a teenager again)—but every now and then, you may notice that your stomach turns into a black hole for no apparent reason. What gives?
For the record, an increased appetite can mean feeling hungrier than normal, feeling hungry more often, or feeling hungry even after you’ve eaten, according to Danielle McAvoy, M.S.P.H, R.D., a dietitian with Strong Home Gym. One-off events such as overeating or doing an extra tough workout are likely to affect your appetite for the following day, but if your appetite’s been in overdrive for more than a few days, something else might be up.
Here are six potential reasons why your appetite increased out of the blue, plus when your constant stomach grumbles warrant a visit to the doctor.
1. Lack Of Sleep
Anyone who has ever experienced multiple sleepless nights knows that it can wreak some serious havoc on your life. A consistent lack of sleep (an average of fewer than six hours per night) can make you tired throughout the day and leave you feeling irritable and unable to focus. It can also make you feel hungrier—even when you’re consuming enough calories, according to McAvoy.
A lack of sleep causes our ghrelin levels to increase and our leptin levels to decrease. Ghrelin, known as the hunger hormone, signals us to eat, while low levels of the hormone leptin tell our bodies our fat stores are low and that we should eat.
As if a good night’s sleep wasn’t already important enough, “getting enough sleep is important for regulating appetite,” McAvoy says.
2. Blood Sugar Issues
A sudden increase in appetite could also stem from blood sugar issues, says Holly Klamer, R.D., a writer for MyCrohnsAndColitisTeam. When your body doesn’t produce enough insulin (the hormone that regulates glucose levels and appetite) or your cells become desensitized to it, your cells become starved for energy. This is the case in diabetes, a chronic health condition that affects the body’s ability to turn food into energy and leads to high blood sugar, which then contributes to excessive hunger, particularly for foods high in sugar.
Meanwhile, medical conditions such as Cushing’s syndrome, in which the body produces too much cortisol, as well as certain medications like antipsychotics, can also contribute to insulin dysfunction. The result: increased appetite and changes in weight.
Your doctor likely checks your blood sugar levels to ensure they’re healthy at your annual physical, but don’t hesitate to schedule an appointment if you have concerns.
3. A High-Carb Diet
Have you recently switched diets? Diets high in carbohydrates, especially carbohydrates with a high glycemic index, could also cause an increase in appetite, according to McAvoy. High glycemic index foods, such as white bread, cause a sharp spike and rapid decline in blood sugar. “The drop in blood sugar can cause you to feel hungry,” McAvoy says. “Pairing carbs with a protein or fat can help slow down digestion and reduce their impact on blood sugar and appetite.”
4. Thyroid Issues
Since the thyroid regulates our metabolism, thyroid dysfunction can affect your appetite by either increasing or decreasing it significantly. An overactive thyroid (called hyperthyroidism), in particular, can make people want to eat more while still causing weight loss, according to the American Thyroid Association. Other symptoms of hyperthyroidism include a rapid or irregular heartbeat, sweating, and muscle weakness. If you’re experiencing any of these symptoms in addition to feeling ravenous all the time, speak with a doctor.
Occasionally when we think we’re hungry, we might actually just be in need of a tall glass of water. “Sometimes the brain mistakes hunger for thirst,” says McAvoy. “To determine if you are hungry or dehydrated, drink a glass of water and wait a few minutes to see if your hunger subsides,” she suggests. Since dehydration can also make you feel lightheaded and tired, look out for those signs that you need H2O, not another snack, too.
6. New Medications
Certain medications can also cause changes in appetite, so take note if you started a new prescription recently. Medications like antidepressants, beta-blockers, and epilepsy drugs, specifically, have all been known to increase appetite.
Whenever you’re about to start taking a new medication, ask your pharmacist about potential side effects—and talk to your healthcare provider if you notice an increase in appetite or weight gain that you don’t feel comfortable with.