What causes tiredness after eating a meal?

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Digestion is a process that requires additional blood supply to the stomach and digestive tract, which means there is less blood supply available for the brain.

It is therefore normal to feel a little tired for an hour or so after you eat a meal, but extreme tiredness after eating is likely to be caused by an undiagnosed health problem. There are several health issues that can cause tiredness after eating that could require medical attention.

Coeliac Disease

Coeliac disease is a malfunction of the immune system related to the digestion of gluten, which causes the immune system to attack the lining of the stomach after eating gluten. Undiagnosed coeliac disease can be life-threatening so it is important to see a doctor if you have symptoms after eating gluten. The best way to treat coeliac disease is to eliminate gluten from your diet. There are many gluten-free products available for sale including gluten-free flours and cereals for making bread and cookies. Because many processed foods contain gluten you must be vigilant in checking the labels of products before you buy them.


Lethargy and tiredness after you eat is a common symptom of diabetes and even medicated diabetics can suffer from tiredness after they eat if the medication levels are not correct. Diabetics must watch what they eat because high blood-sugar levels can result from eating carbohydrates, causing tiredness and lack of energy after eating. Consuming smaller meals and eating more frequently often corrects this symptom, but medication levels also need to be checked by your doctor regularly. Following a strict diabetic diet is also important, choosing low-carbohydrate foods, lean meats, low-fat or nonfat dairy products and including plenty of fresh fruits and low starch vegetables in your diet. Try to avoid processed foods that often contain hidden sugars.

Fast Food

Fast foods can also cause fatigue after eating even in healthy people without allergies or health disorders. This is because fast foods frequently contain refined sugar and flour and saturated fats. Saturated fats are difficult for the body to process and require large amounts of blood and oxygen to digest. This causes fatigue in many people as the rest of the body is robbed of blood and oxygen while the stomach is processing the saturated fats. Refined sugars are also found in high levels in the bloodstream after eating many fast foods.

Food That Causes Bloating

Bloating after eating can often cause a feeling of tiredness and weakness of the muscles. Bloating can be caused by Candida, over growth in the gut, intestinal parasites, Crohn's disease, ulcerative colitis, as well as many other common food allergies. Foods that commonly cause bloating include raffinose, a sugar found in cabbage, beans and Brussels sprouts; cooking, though, reduces the bloating effect of raffinose. Wheat also causes bloating especially when people have an allergy to wheat and gluten. Legumes also can cause bloating because they are a combination of starch and protein.