Feeling fatigued after a meal — medically known as postprandial somnolence — is not an uncommon reaction for most. After eating big meals, you may feel sleepy and need rest. The type of food you eat and portion size can also contribute to feelings of fatigue.
But should eating always make you feel extremely fatigued? Likely not. Extreme fatigue after a meal may be a sign of an underlying health condition in some cases. Here, Ashkan Farhadi, MD, a gastroenterologist at MemorialCare Orange Coast Medical Center in Fountain Valley, California, shares the most common factors that can cause you to feel extreme fatigue after eating.
1. Your Body Is Digesting Food
“When you digest food, your digestive tract is getting an increase of blood supply,” Dr. Farhadi says. As a result, this can reduce blood supply to the brain, causing feelings of sleepiness. Farhadi explains that this feeling is normal and can actually bring about a state of calm rather than just fatigue.
“A release of serotonin occurs when you digest food, and the gut is one of the major producers of that serotonin,” Dr. Farhadi says. This creates a relaxing effect in the body, causing you to feel calm after eating.
How to Fix It
It might help to anticipate that eating may leave you feeling a bit sleepy. But if you feel extreme fatigue after eating even a small amount of food, this could indicate a medical issue, Farhadi says. In that case, follow up with your healthcare provider to figure out what may be going on. They can get you tested and help you understand what’s causing your symptoms.
2. You’re Eating a Lot of Protein and Carbs
Eating a lot can make you drowsy, especially if you are eating foods higher in protein and carbohydrates. Everyday foods that are high in protein include dairy, chicken, and soy products, while high-carb items include pasta, white bread, and sugar, the Cleveland Clinic explains. When you consume a high amount of these types of foods, your digestive system can get overloaded, and your body releases hormones that cause you to feel sleepy.
Additionally, if you are eating highly processed foods or foods with little nutritional value, you may have less energy, according to the National Institute on Aging.
How to Fix It
Try adjusting what you eat — and how much of the food you’re eating. Aim for smaller portions throughout the day and focus on including complex carbohydrates, beans, and non-starchy vegetables in your meals.
3. You Have Diabetes
Overwhelming tiredness after eating can be a sign of an underlying medical condition, like diabetes. Diabetes is a health condition that affects your body’s production or use of insulin — a hormone that moves glucose (aka sugar) from the foods you eat into your body’s cells, according to the American Diabetes Association (ADA). For people with diabetes, glucose lingers in the bloodstream, where it can cause an array of symptoms.
While most people with early stage type 2 diabetes don’t often experience symptoms, they may start noticing signs of the condition as it progresses. The common symptoms of type 2 diabetes include extreme fatigue, excessive thirst or hunger, frequent urination, and blurry vision, the ADA explains. Farhadi adds that while chronic fatigue and diabetes are separate conditions, having high blood sugar can affect how much glucose your brain is receiving for energy, which can result in symptoms like fatigue and lack of energy.
How to Fix It
A blood test can help determine if you have diabetes, according to the Mayo Clinic. If you receive a diabetes diagnosis, your healthcare provider can offer personalized treatment options, which may include lifestyle and dietary changes, insulin, and other medications.
4. You Have Celiac Disease
Celiac disease is an immune reaction to eating foods that have gluten. If you have celiac disease, eating gluten can damage your small intestine lining and prevent it from absorbing essential nutrients over time, the Mayo Clinic says. Celiac disease can cause an array of GI symptoms, including bloating, constipation, and diarrhea.
However, fatigue is also a common symptom for people with celiac disease, especially for those who eat foods with gluten, according to the National Celiac Association.
How to Fix It
Blood tests and other diagnostic exams can confirm if you have celiac disease. If you do, you’ll want to make sure to follow a strictly gluten-free diet (that includes what you eat at meals, as well as supplements and medications). When you go out to eat, ask about gluten-free options and cross-contamination with gluten.
5. You Have Small Intestinal Bacterial Overgrowth (SIBO)
SIBO — a condition that happens when you have too much bacteria in the small intestine — can cause fatigue after eating. SIBO happens when food becomes stagnant (or stuck) in the small intestine, which makes it easy for bad bacteria to add up and cause malabsorption, according to the Mayo Clinic.
Alongside fatigue, SIBO may also cause diarrhea, unintentional weight loss, loss of appetite, abdominal pain, and bloating.
How to Fix It
If you suspect you may have SIBO or be at risk of the condition, make an appointment with your healthcare provider to get tested. If you receive a diagnosis of SIBO and often feel tired after eating, ask your provider about an eating plan that’s right for you. The Mayo Clinic explains that avoiding lactose (dairy products) or eating a low-FODMAP diet, for example, can reduce fatigue in people who have SIBO.
6. You’re Eating Large Meal Portions
The quantity of food you eat is another major factor in how you feel after a meal — whether it’s nutritious or not. Eating large quantities of nutritious food (like beans and brown rice, for example) can make you feel tired. Likewise, large amounts of highly processed foods (like chips, pastries, or fried foods) can also make you feel like taking a nap afterward.
How to Fix It
Try reducing the portion size of your meals, and eat four or five smaller meals per day instead of three large meals. This allows your body to digest a manageable amount of food throughout the day and keep you from feeling dips in energy, per the Cleveland Clinic.
7. You Have Food Allergies
When you eat something you’re allergic to, your immune system kicks in to protect your body from the harmful substance (in this case, the food you’re allergic to). This is typically when fatigue sets in. The Food and Drug Administration (FDA) states that some of the most common food allergens include milk, eggs, fish, shellfish, peanuts or tree nuts, wheat, and soy. So if you have any of these allergies, avoid eating the food you’re allergic to to prevent fatigue and other more serious allergic reaction complications.
“Keep in mind that most food allergies come with a variety of other symptoms,” Farhadi says. If you have fatigue alone, it may be another issue. That’s when it’s a good idea to call your healthcare provider and get to the bottom of your symptoms.
How to Fix It
Speak to your healthcare provider if you suspect you have a food allergy. They can help determine if you are, in fact, allergic to certain foods or what the exact cause of your fatigue may be.
8. You’re Just Tired
Sometimes the reason you feel fatigued after eating a meal is simple: You’re just tired in general. The body expends energy when eating and digesting a meal, and if you’re already sleep-deprived, you can end up feeling even more tired.
“The act of eating can be tiresome for people with chronic fatigue syndrome or another illness,” Farhadi says. Just remember, in most instances, feeling tired after eating a meal is normal and expected, he adds.
How to Fix It
Make sure you are getting the recommended seven to nine hours of sleep per night. Getting good sleep helps keep your energy levels up, reduces your risk of feeling extra sleepy after eating, and is good for overall health.
