We all take it for granted that food gives us energy. So why do you feel tired after a big meal?

Tiredness after eating may indicate that the body is working harder to digest food. However, it could also indicate that something is wrong with the glucose and insulin response or that an underlying disease is the cause.

In this article, we discuss post-meal fatigue and its causes. We also share 7 effective tips for avoiding fatigue after meals.

What is fatigue after eating?

Many people feel tired after breakfast, lunch, dinner, or after any meal or intake in general. This tiredness, fatigue, or, more commonly, a slump, is known as postprandial drowsiness or ‘food coma’ and occurs mostly after large intakes or meals.

  Why do I have fatigue after eating?

There is no single cause for the feeling of drowsiness after eating.

One of the most widely accepted theories in the scientific community is that blood is diverted to the digestive tract and away from the brain when we eat. However, other studies say that after eating, hormones are released in the gut that influence sleep at the brain level.

Although there is no consensus on a single cause, getting tired after eating is common in many people’s daily lives.

Fatigue after eating: what are the most common causes?

These are the most influential factors:

1. Type of power supply

Any food can cause drowsiness, but foods rich in unhealthy fats (fried foods, red meat and products made with cream or butter) and mainly those rich in carbohydrates (pasta, bread, white rice, chips and pastries) have been associated with increased sleepiness after eating. In addition, some foods contain melatonin (such as eggs or pistachios), the hormone that regulates sleep, which may also influence a greater feeling of sleepiness after eating. 

2. Large meals

Large menus or celebratory meals often lead to more fatigue after eating.

3. Meal times

The body’s circadian rhythm controls the sleep-wake cycle. It helps you fall asleep at night, generates alertness during the day, and decreases energy between 13 p.m. and 16 p.m.

4. Alcohol with meals

Alcohol makes you drowsy. If you drink it with a meal, you are much more likely to feel more tired after eating. 

5. Low blood sugar

The famous ‘sugar crash’ after eating is nothing more than a myth, as most healthy people can regulate their blood sugar levels correctly by releasing the right amount of insulin during eating.

However, some people suffer from reactive hypoglycaemia or postprandial hypoglycaemia. This is a significant drop in blood sugar after meals. It occurs 2-5 hours after a meal and is different from the usual drowsiness after eating, usually 30-60 minutes after a meal.

6. Insulin resistance

When insulin cannot deliver glucose, an important form of energy, to the cells, insulin resistance occurs and can cause fatigue after a large meal.

The most common cause of insulin resistance is diabetes or pre-diabetes. Still, it can also be caused by other factors such as a sedentary lifestyle, chronic stress or a BMI over 30, among others.

7. Underlying diseases

Certain diseases such as iron deficiency anaemia, fibromyalgia, depression and anxiety, diabetes, thyroid problems or obstructive sleep apnoea cause an increased feeling of fatigue and tiredness.

What are the symptoms of postprandial sleepiness?

1. Feeling of heaviness in the body.
2. Dream.
3. Fatigue.
4. Difficulty concentrating.
5. Mild confusion.

How to avoid fatigue after eating?

Drowsiness after a meal can occur at the worst times: just before a working day or during an important event.  But there’s a solution. Here are 5 effective tips to keep your energy levels up and avoid post-meal fatigue:

1. Healthy and balanced diet: rich in vegetables, low in simple carbohydrates and sugars, and unhealthy fats.
2. Avoid large meals: if you are hungry, eating smaller meals is better.
3. Do not drink alcohol with meals.
4. Get enough sleep.
5. Daily physical activity.
6. Walk after eating for at least 10-15 minutes.
7. Drink tea: it aids digestion and provides antioxidants and a little theine to help minimise fatigue after eating.

Feeling tired after eating? Pay attention to your body’s signals

Feeling tired after eating is quite common. However, in some cases, it can be a sign of an underlying health problem, such as diabetes or insulin resistance.

Although we do not know the exact cause of this post-meal fatigue, it is advisable to apply the recommendations in this article and observe your symptoms and possible changes. If you still feel too tired after eating, you should visit your GP for the necessary tests and to rule out other causes.

In addition to avoiding large meals, walking after eating, being physically active, avoiding alcohol, drinking beverages such as tea, and eating a balanced and healthy diet, remember that maintaining adequate levels of vitamins (such as vitamin D or B vitamins) and minerals (such as magnesium or silica) is very important to maintain energy levels. There are natural supplements that can help you do this.