Excessive sleepiness after eating is actually quite common and can have several causes. Most are easily fixable with some changes to diet, sleep and/or exercise. If you continue to have excessive sleepiness after making these changes, contact your doctor. You could have an underlying medical condition causing the problem.
One of the most common causes is overeating. Any time you eat, your body will route more blood to your stomach and bowels to aid the digestion process. However, if the meal is too large, the body has to route even more blood to those areas and for longer and this can cause your brain to be mildly deprived of blood and nutrients. This in turn leads to the sleepiness. To avoid this problem, eat smaller meals.
The next most common cause is what you eat. Foods that are high in sugar or refined carbohydrates digest more quickly. This leads to a rapid rise in sugar in your blood stream, which is followed by a rapid drop. The rapid drop is what causes you to feel sleepy. To avoid this, eat foods low in sugar, complex carbohydrates (think whole grain or “brown” foods), and make sure you have a protein source with each meal (meat, nuts, cheese, eggs). The protein will slow your digestion and reduce the rapid rise and fall of your blood sugar. It will also make you feel fuller with less food which helps with the problem of overeating as well.
However, there is a note to be made about protein sources. Tryptophan, an amino acid found in foods such as turkey, chicken, nuts, milk, seeds, eggs and fish, stimulates the release of serotonin, a chemical which makes your feel calm, stable and happy while working to regulate your sleep patterns. After eating foods high in tryptophan, you might feel tired and lethargic as a result of the serotonin being released in your body. To avoid this, you should eat complex carbohydrates or lower carbohydrate foods (non-starchy vegetables for instance). Tryptophan needs sugar to get to your brain so not loading up on the simple carbohydrates will slow this process.
Too much caffeine can actually make you sleepy also. So if you are using coffee, soda or tea stay awake all day. It could actually be back firing. To avoid this, start weaning yourself to decaffeinated beverages or better yet water. Water also plays a part in your alertness. If you are dehydrated, you will feel more tired. To avoid this, keep water with you at all times and sip on it throughout the day.
If you feel you need the caffeine to stay awake you may also be not getting enough sleep or your sleep may be poor. Lack of adequate sleep can affect your digestive system’s effectiveness and your energy levels. To avoid this, try to get more sleep. Most people need 7-8 hours of sleep a night. If you have trouble sleeping, see your doctor. You could have an underlying medical problem.
There is some possibility that food allergies or intolerances can be playing a role. The best thing to do in that case is keep a journal of what you eat and how sleepy you get. If see that a particular food seems to be causing the problem, call your doctor and get tested for allergies. Even if you do all these things you may still have some sleepiness after eating. It’s just a natural part of digestion. To perk yourself back up if you are sleepy try getting up and getting a bit of exercise. Walk around for a bit, do a few jumping jacks, or stretch. This can also be done preventively to avoid sleepiness as well.
Again, if you have tried all these things and are still getting sleepy after eating, call your doctor. You may have a medical condition, such as diabetes, that needs to be addressed.