Fatigue after eating - why it occurs and how to prevent it

Remember in kindergarten when we used to take a whiff? Even now, do you still feel faint to drowsy after some meals, and a hundred urges to lie down for a while? You're not alone. A surprising number of people suffer from post-meal fatigue, and often there's nothing really special about it. Post-meal fatigue can be caused by a number of factors - the wrong combination of foods, lack of macronutrients, imbalance, portion size, speed of eating.. and much more. A slight post-meal fatigue is actually quite normal, but let's take a look at why it most often occurs and how it can be, at least partially, prevented.

Reason number one - digestion itself

I probably don't need to take you long here with the theory that food is our biggest source of energy and that we need it not only to have energy for all activities, including lifting weights, but the body simply needs energy for its very ordinary functioning - i.e. for basic life functions such as breathing. Our digestive system breaks down food into fuel (glucose). Macronutrients then provide our bodies with calories (energy). The first reason why we often feel sleepy after eating is the process of digestion itself. This is because during this process, blood from other organs moves to the stomach and digestive tract, causing blood to drain from other organs, including the brain. The stomach begins to contract periodically, and food begins to be processed in it. Stomach juices begin to be produced, which help to digest the food so that our body can make the most of the available nutrients. The movement of blood to the organs related to digestion is the first and most common reason why we are more tired about an hour or two (depending on factors such as portion size and digestibility of the nutrients contained) after a meal.

Reason number two - carbohydrates, sugars, hormones and blood sugar regulation

With every meal we supply the body with some sugars - if we take in too many at one time, concentrate on simple sugar sources, or take in complex sources, but on their own without the "hindering" components such as protein, fiber, or fat, there will be a rapid increase in energy, but this is short-lived and very soon drowsiness sets in. This is because carbohydrates are digested the fastest of all nutrients, and the moment they enter the blood, blood sugar - i.e. glucose - rises. After consuming carbohydrate sources, the brain sends a signal to produce the hormone insulin, which helps cells take up glucose and helps regulate blood sugar levels. If the spike in blood sugar levels is too rapid, which can be caused by, for example, a high intake of simple sugars, rapid fatigue will occur.

Moreover, insulin does not only affect blood sugar. It can also stimulate the production of tryptophan. If tryptophan is present in the brain in greater quantities, serotonin and melatonin production is increased. Melatonin and serotonin are the two main sleep hormones whose higher concentrations cause sleepiness. However, it is crucial to distinguish between simple and complex carbohydrates. Simple carbohydrates and refined sugars are broken down very quickly in the body into glucose, which the body uses as an energy source immediately, so it is a short-term energy source. Complex carbohydrates, on the other hand, are a great source of energy that is released gradually, so there is no rapid onset of fatigue and fatigue. Even so, make sure that the carbohydrate side dishes at your main meals are not too large.

Reason number three - too much fat or inappropriate types

If, after reading the previous point, you are thinking that you will therefore cut down on carbohydrates and instead add fat, then we must warn you, because even too much fat can cause fatigue. The reason why this happens is basically simple. The stomach, as the first organ of the digestive tract, processes different types of macronutrients at different rates. Carbohydrates are the first to leave it, followed by proteins, and fats last. If we take in too much fat, the digestion of other nutrients will be slower and the whole digestion process will take longer. As we already know from reason number one, digestion itself costs the body a significant amount of energy. This is why we feel so full and tired after heavy fatty meals.

Of course, the type of individual fats we consume also plays a role. You already know that there is no such thing as fat. Some types, especially saturated fats, can cause digestive problems and can even rob us of energy and reduce our ability to concentrate.

Reason number four - too much processed food

If your diet consists mostly of processed foods, this may be another reason why you feel tired after eating. All sorts of semi-processed foods, breakfast cereals, sugary drinks, bakery products, cold cuts, fried foods, fast food, often contain nutrients that are not optimal for physical or mental performance, let alone health. In such products we often find large amounts of refined sugars, unsuitable types of fat and a good dose of salt. On their own, these substances are not particularly beneficial, but their combination is literally a nutritional drama, as they can mutually amplify the negatives they have individually. Moreover, these foods often taste very good, so the problem is that we lose control, and if we eat too much of them, it will affect not only our performance, but certainly other aspects of our health and appearance.

Reason number five - foods rich in tryptophan

Even foods that fall into the category of healthy eating can cause fatigue. In fact, some foods, especially protein sources, are rich in tryptophan, the effects of which we have already seen in point two. When tryptophan is present in the brain in large quantities, it has the ability to influence the production of serotonin and melatonin, hormones that affect sleep and can cause drowsiness. Such foods include poultry, salmon, eggs, dairy products, seeds and even spinach.

Reason number six - you eat in a hurry and don't notice what you're eating

When we eat in a hurry or in front of the TV, we often lose track of what we are eating and, more importantly, how much we are eating. The effect of splitting our attention into many areas is that we unconsciously eat more than we need and with overeating comes, in addition to a heavy stomach, a sluggishness and drowsiness. Moreover, if we eat in a hurry, we tend to reach for some not-quite-healthy options more often and then we actually go back to the reasons mentioned above. Or, eating too much sugar causes drowsiness, eating processed foods causes drowsiness, eating too much fat can cause drowsiness. Does this pod need any more explanation?

Reason number seven - portion size

As we've hinted at before - portion size is another important factor that affects how we feel after a meal. The more food our digestive system has to process, the longer it takes it to concentrate its "attention" on the organs of the digestive system and the longer it logically takes to go elsewhere. So if our body is trying to process giant batches of food, you can't expect your brain to go full speed ahead. Eating large portions also raises blood sugar levels, which leads to insulin production and subsequently fatigue, as we've discussed above.

Number eight - allergies and diseases

Another hard to control reason that can cause fatigue after eating is allergies and illnesses. Diabetics need to be most wary of this, as they need to carefully monitor what they eat and how much they eat to avoid rapid changes in their blood sugar levels. The body of diabetics cannot produce insulin and process glucose properly. This is also why people with diabetes need to know how much sugar they will take in with their meals and therefore how much insulin will be needed to process it. As we already know from point two, a sudden spike in insulin can cause a rapid increase and decrease in energy. Effective prevention then is regular food intake in smaller portions. It is similar with allergies and intolerances. If you feel tired after a certain meal, this may be the first sign of a developing allergy. The moment fatigue after certain foods is accompanied by other symptoms such as rashes, nausea or headaches, see a doctor or try an elimination diet.

How to solve or even prevent food fatigue problems?

If you are wondering how to deal with or effectively prevent post-meal fatigue, we have some tips for you. The first and most basic one is to eat a balanced diet - that is, to have all macronutrients in your diet in reasonable amounts. Avoid meals that are too high in fat or carbohydrates. Eat varied, regular and sensible portions. Try to eat foods in as natural a form as possible and limit your intake of overly processed foods, convenience foods, instant foods, fast food and sweets. Also avoid refined sugars and inappropriate sources of fat.

If you are experiencing fatigue after eating, dividing your intake into multiple portions per day can also help. Don't forget to practice mindful eating - no computer, newspapers or social media during meals! During your meal, focus only on the food, savor it, eat slowly, chew well, and notice your body's signals. You should not neglect sufficient drinking, regular exercise and, of course, quality sleep. If you feel tired after certain foods, it's worth thinking about whether it's possible that a food allergy is behind it, especially if it's accompanied by other symptoms such as rashes, nausea and more. If this is the case, see your doctor to discuss the situation with him or her, or you could try an elimination diet.

What can I take away from this article?

Light fatigue after eating is perfectly fine and is actually quite common. Digestion itself can be to blame, but also inappropriate dietary composition, large portions, eating in a hurry, too much sugar or fat, excessive intake of processed foods, fast food, sweets, and of course food allergies can also be the cause. But in most cases it is quite enough if you eat calmly, regularly and in reasonable portions. Make sure your meals are beautifully coloured, balanced and don't get distracted while eating, eat mindfully and focus on your food. If your tiredness is too frequent or comes after certain meals, see a doctor to be sure it is not a food allergy.

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