Postprandial Sleepiness, or more commonly known as feeling tired after eating, is a slump in energy levels that primarily presents itself after eating a meal. We will explore the signs and symptoms of post-meal fatigue and identify problematic foods and lifestyle choices that can contribute to this condition.
What causes tiredness after eating?
Like most conditions, causes are not limited to one specific thing, instead there are several causes that can contribute to overwhelming tiredness after eating.
The most common cause is the body's natural response to the digestion and absorption process, which diverts energy to the digestive system. Other factors include consuming meals high in refined carbohydrates which can lead to rapid fluctuations in blood sugar levels, triggering feelings of tiredness. Healthy high protein foods can also contribute to tiredness, especially after eating.
Other common causes that can cause tiredness include, lifestyle choices and the body’s natural sleep pattern.
What are the symptoms of post-meal fatigue?
The symptoms of post-meal fatigue may differ in everyone, but common signs include a general sense of tiredness, lethargy, sleepiness, and difficulty concentrating. The severity of tiredness can also vary, with some individuals experiencing overwhelming tiredness after eating and the desire to take a nap.
Other symptoms include brain fog, decreased alertness, or a lack of energy to engage in activities.
How long does post-meal fatigue last?
You can expect post-meal fatigue to be more noticeable if you have eaten a large meal that has mostly consisted of carbohydrates and proteins. Typically, feeling tired after eating is a normal biological response, at present there is no research to suggest how long it will last for, however if you find that this seems to be getting in the way of your day-to-day life, you should try changing the quantity and contents of your food to see if there is any improvement in your energy levels.
What foods can cause tiredness?
Foods that are rich in proteins and carbohydrates can cause tiredness after eating particularly when compared to others.
Many foods rich in protein contain a type of amino acid called tryptophan which helps the body produce a natural chemical called serotonin. In turn, serotonin helps to regulate the body’s natural sleep pattern and moods. Protein rich foods containing tryptophan can cause an increase in serotonin levels, promoting the feeling of relaxation and tiredness.
Common sources of protein that contain Tryptophan:
- Cows milk
- Nuts and seeds
Carbohydrates and proteins work hand in hand when it comes to causing tiredness after eating. Whilst protein rich foods contain Tryptophan, carbohydrates help the body to absorb it.
Common foods that contain carbohydrates include:
- Bread (mainly white)
- Sweets and junk food
- Cakes and pastries
How to stop feeling tired after eating
Adopting certain lifestyle changes alongside mindful dietary choices can help to reduce the severity of your tiredness.
- Quality not quantity: Consuming smaller meal portions throughout the day can help prevent overloading your digestive system and minimise energy crashes.
- Balance your diet and prioritise nutrient-rich foods: Have a balanced diet that consists of a variety of fruits, vegetables, whole grains, lean proteins, and carbs to provide essential vitamins and minerals for energy production. Try to avoid overloading on carbs.
- Mindful eating: Try to listen to your body’s own hunger cues and ensure you do not overeat. Chew your food slowly and be mindful of the quantity you are eating.
- Stay hydrated: Dehydration can contribute to feelings of fatigue, so ensure you're drinking enough water throughout the day. If you still feel hungry after eating, this could be a sign that you are dehydrated, instead of opting for more food, try and drink a glass of water.
- Manage stress levels: Chronic stress can impact digestion and change eating habits altogether. Engage in relaxation techniques like deep breathing exercises or meditation to reduce stress.
- Consider a food intolerance: If you have made lifestyle and dietary changes but you are still experiencing post meal fatigue, it could be a sign that you have a food intolerance. Try to identify your problem foods so you can eliminate and replace them in your diet. A food intolerance test can also help to identify your problem foods. Read our helpful medical guide what is a food intolerance for more information on causes, triggers, symptoms, treatment and diagnosis of a food intolerance.
Is feeling tired after eating a sign of diabetes?
Feeling sleepy after eating is a sign of diabetes, however it can also be a sign of a food intolerance, poor diet, and lifestyle. Fatigue in people with diabetes particularly after eating can occur because of fluctuations in blood sugar levels. However, fatigue alone can not diagnose diabetes, instead; fatigue would typically be accompanied by other symptoms such as feeling very thirsty, and needing to pass urine more frequently (particularly at night).
Could it be a sign of food intolerance?
Experiencing fatigue after eating can be a sign of a food intolerance. When you consume a food to which you are intolerant, it can trigger various digestive symptoms, including bloating, gas, and discomfort. These symptoms can deplete your energy levels and leave you feeling tired and fatigued after eating.
If you suspect that your post-meal fatigue is related to a food intolerance, it is important to look out for other common symptoms of an intolerance such as, bloating after eating and experiencing diarrhoea after eating.
When should I see a Doctor?
Post meal fatigue is usually completely harmless. Most people have experienced an afternoon slump, or a “food coma” after eating a large meal. It is important to monitor patterns in your post meal fatigue to try and identify if it is caused by a particular food or if it is persistent and starting to affect your quality of life.
If you are experiencing other symptoms alongside your fatigue such as weight loss, chronic fatigue, or extreme lethargy, you should contact your GP.