Chronic fatigue syndrome – what might be missing from my diet?

Chronic fatigue is often put down to overwork, stress or a lack of sleep. However, if a lack of energy persists for weeks, it is worth taking a closer look at your diet as well. An insufficient energy intake, or deficiencies in iron, vitamin B12 or folate, can contribute to weakness and a reduced tolerance for physical exertion. It is important to note, however, that chronic fatigue syndrome (ME/CFS) is a complex condition, and its causes cannot be reduced to a deficiency in a single vitamin or mineral. Diet may be one factor requiring assessment, but it is no substitute for a medical diagnosis.

1. First, check whether you’re simply not eating enough
2. Iron – one of the first nutrients worth looking into
3. Vitamin B12 and folates – particularly important on elimination diets
4. Vitamin D, protein and hydration – simple things that are easy to overlook
5. What should you do if you’ve been feeling low on energy for a long time?
6. FAQ – Frequently Asked Questions

First, check whether you’re simply not eating enough

This is one of the most practical places to start. People who are trying to lose weight, are very active, eat irregularly or cut out many foods may be providing their bodies with too little energy over a prolonged period. In such cases, the problem may not be a deficiency of a specific vitamin – the body may simply be lacking fuel.

So, for a few days, it’s worth writing down everything you eat and drink, without trying to adjust your diet just for the sake of your notes. Take note of whether you regularly skip breakfast or lunch, whether dinner is your main meal, whether your diet has been severely restricted in terms of fats or carbohydrates, and whether your physical activity has increased without a corresponding increase in food intake. In practice, a good starting point is regular, balanced meals containing a source of protein, carbohydrate-rich foods, vegetables or fruit, and fats. Rather than immediately looking for "energy-boosting" supplements, it’s worth getting the basics right first.

Iron – one of the first nutrients worth looking into

Iron deficiency can lead to anaemia, the symptoms of which may include, amongst others, tiredness, weakness, reduced exercise tolerance and shortness of breath. Particular attention should be paid to this by women with heavy periods, pregnant women, blood donors and those following poorly planned elimination diets.

What can you do straight away? Check whether your diet regularly includes foods that are sources of iron. These include, amongst others, meat, fish and seafood, and, from plant sources, pulses, tofu, seeds and certain cereal products. The absorption of non-haem iron from plant-based foods can be improved by combining them in a meal with a source of vitamin C, such as peppers, kiwis, berries or citrus fruits.

However, it is not advisable to start taking high doses of iron "on a trial basis". It is best to confirm a suspected deficiency with appropriate tests and discuss it with a doctor, as fatigue may have a completely different cause.

Vitamin B12 and folates – particularly important on elimination diets

Vitamin B12 contributes, amongst other things, to the proper functioning of the nervous system and the formation of red blood cells. A deficiency can cause anaemia, weakness and fatigue, and in more advanced cases, neurological symptoms as well.

Those on a vegan diet should be particularly mindful of their B12 intake, as it occurs naturally mainly in animal-derived products. The risk of deficiency may also increase with certain gastrointestinal diseases and malabsorption disorders. In the case of a vegan diet, it is essential to ensure a reliable source of B12, most commonly through appropriate supplementation.

The second key nutrient is folate. It is found, amongst other things, in green leafy vegetables, pulses and some other vegetables. Rather than trying to guess which nutrient is lacking, it is wiser to discuss the need for tests with a doctor if you are experiencing prolonged fatigue.

Vitamin D, protein and hydration – simple things that are easy to overlook

Low levels of vitamin D may be associated with, amongst other things, muscle weakness; however, fatigue alone is not sufficient to diagnose a deficiency. In Poland, the issue of vitamin D is particularly important due to limited skin synthesis during part of the year. Supplementation should be chosen in accordance with current recommendations, taking into account, amongst other things, age, health status and individual risk factors.

It is also worth taking a look at protein. If your daily diet contains virtually no eggs, dairy, meat, fish, tofu, pulses or other good sources of protein, your diet may need improving. The simplest rule is to include a source of protein in every main meal. You mustn’t forget about fluids either. Dehydration can cause tiredness, headaches, poor concentration and reduced exercise tolerance. However, rather than forcing yourself to drink an arbitrarily set number of litres, it’s best to drink regularly throughout the day and increase your fluid intake during hot weather and when exercising.

What should you do if you’ve been feeling low on energy for a long time?

It’s best to start with a simple plan. Keep a diary of your food, sleep and how you feel for a few days. Check whether you’re eating regularly, whether each main meal contains a source of protein, and whether your diet includes vegetables, fruit, whole grains, sources of healthy fats, and foods rich in iron and vitamin B12. Also pay attention to your fluid intake, alcohol consumption and caffeine intake.

If your fatigue persists despite sleep and rest, significantly impairs your daily functioning, or is accompanied by other symptoms, you should consult a doctor. The cause may be not only nutritional deficiencies, but also anaemia, thyroid disorders, sleep problems, infections, side effects of medication, chronic illnesses or mental health conditions. If ME/CFS is suspected, a characteristic issue may also be a worsening of symptoms following even minimal exertion (post-exertional malaise, PEM). In such a situation, undertaking intensive training in order to "regain energy" should not be regarded as universal advice.

"A well-balanced diet is fundamental, but in certain situations, supplementation can help to replenish nutrients that are difficult to obtain in sufficient quantities or where a deficiency has been identified." Anna Zięba – Dietitian

FAQ – Frequently Asked Questions

What nutrients are most commonly lacking in the diet when you’re feeling tired?

It is worth paying particular attention to ensuring an adequate intake of energy, iron, vitamin B12 and folate. In certain situations, vitamin D may also be important. However, fatigue alone is not sufficient to diagnose a specific deficiency.

What tests should be carried out if you are constantly tired?

The range of tests should be based on your symptoms and medical history. Your doctor may consider, amongst other things, a full blood count and tests to assess your iron, vitamin B12 and folate levels, as well as thyroid function. There is no single set of tests that is suitable for everyone.

Can iron deficiency cause fatigue?

Yes. Iron deficiency, particularly if it leads to anaemia, can be associated with weakness and reduced exercise tolerance. However, high doses of iron should not be taken as a supplement without good reason.

Does vitamin B12 help with fatigue?

B12 supplementation is important when intake is insufficient or a deficiency is present. However, taking extra B12 is not a one-size-fits-all solution for boosting energy in someone who already has sufficient levels.

What should I eat if I feel tired all the time?

Start by eating regular, balanced meals. Include a source of protein and energy in every main meal, eat a variety of vegetables and fruit, do not unnecessarily cut out entire food groups, and remember to stay hydrated.

Can ME/CFS be cured with a diet?

There is no basis for presenting any specific diet as a treatment for ME/CFS. A balanced diet helps meet the body’s needs and prevent deficiencies, but ME/CFS requires a broader medical approach.

Sources:

• Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: the biology of a neglected disease https://pubmed.ncbi.nlm.nih.gov/38887284/
• Chronic Fatigue Syndrome https://pubmed.ncbi.nlm.nih.gov/32491608/
• Understanding, diagnosing, and treating Myalgic encephalomyelitis/chronic fatigue syndrome - State of the art: Report of the 2nd international meeting at the Charité Fatigue Center https://pubmed.ncbi.nlm.nih.gov/37742748/