Eating an excessively large meal can make you feel tired, as your body focuses its energy on digesting the food. However, if you feel fatigued after most meals, you may need to do more than just decrease your portion size. Fatigue after eating can have many causes, including allergies, celiac disease, low blood sugar or insulin resistance. Talk to your doctor about your symptoms; she can perform tests to help determine the cause of your fatigue.
Food Allergies
While many allergic reactions can cause swelling of your airways, some food allergies can instead lead to tiredness after eating. In fact, one of the main causes of fatigue is eating foods to which you are allergic. Food allergies can cause fatigue regardless of whether you have digestive concerns. When you eat food you are allergic to, your body treats it like a dangerous foreign substance. Your body uses energy to remove the allergen; with your energy displaced and your system not receiving energy from the food you ate, fatigue can result.
Celiac Disease
Feeling tired after consuming foods with wheat or other forms of gluten can indicate celiac disease. This disease is a specific allergy to gluten, a protein found in wheat, barley and rye. Your body's reaction causes damage to the inner lining of your small intestine, causing bloating, gas, diarrhea and abdominal cramping or pain. Damage to your intestines reduces your body's ability to absorb nutrients from food. Fatigue, especially after eating foods with gluten, may stem from lack of adequate nutrition. Over time, extreme fatigue and weakness can result.
Low Blood Sugar
Another reason you feel tired after eating is that you are experiencing low blood sugar or hypoglycemia. Eating a meal high in refined carbohydrates causes your blood sugar to increase and decrease rapidly; you experience energy and then fatigue. Hypoglycemia can occur during a fast, during intense exercise or more rarely after eating a balanced meal. If you have eaten a balanced meal and experience low blood sugar, you may have reactive hypoglycemia. This disorder typically occurs one to four hours after eating and is characterized by fatigue, dizziness and poor focus.
Insulin Resistance
Sugar is used by your body for energy; it is taken from your bloodstream by the hormone insulin and given to cells to fuel body processes. With excess sugar or carbohydrate consumption, your body must produce more insulin to meet demands. Over time, your cells resist the insulin that is bringing them fuel, a phenomenon known as "insulin resistance." Insulin resistance can lead to obesity and a variety of other health conditions. This disorder is characterized by fatigue after eating,
consistent sugar cravings even after sweets are consumed, increased thirst and frequent urination.
