We all feel tired from time to time. A busy week at work, poor sleep or a demanding family life can leave anyone reaching for another cup of coffee.
But chronic fatigue is different.
If you’ve been feeling exhausted for months, wake up feeling as though you haven’t slept, struggle to concentrate and find that even everyday tasks feel overwhelming, your body may be trying to tell you something.
Fatigue isn’t simply a lack of energy. It’s often a sign that one or more body systems are under strain. Rather than masking it with caffeine or pushing through, it’s worth asking an important question:
Why is my body so tired?
Understanding the possible causes is the first step towards supporting your health and regaining your energy.
What is chronic fatigue?
Chronic fatigue describes persistent, unexplained tiredness that lasts for several months and isn’t relieved by rest.
It’s important to distinguish between chronic fatigue as a symptom and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), which is a complex medical condition with specific diagnostic criteria.
Many people experience chronic fatigue without having ME/CFS. Fatigue can arise from nutritional deficiencies, poor sleep, chronic stress, hormonal changes, inflammation, infections, certain medications or underlying medical conditions.
Because fatigue has so many possible causes, it’s always important to speak to your GP if symptoms are persistent or worsening.
Why does fatigue develop?
Our energy depends on many different body systems working together. When one or more of these systems becomes disrupted, fatigue can develop.
Poor sleep quality
Sleep isn’t simply about the number of hours you spend in bed.
Deep, restorative sleep allows your brain to process information, your muscles to repair and your immune system to reset.
Sleep disruption is particularly common during the menopause due to changes in oestrogen, progesterone and body temperature regulation.
Even if you spend eight hours in bed, poor-quality sleep can leave you exhausted the following day.
Chronic stress
Our stress response is designed to protect us in the short term.
However, when stress becomes constant, the body diverts resources towards survival rather than repair and recovery.
Over time this may contribute to disturbed sleep, poor digestion, increased inflammation and reduced resilience, all of which can affect energy levels.
Nutritional deficiencies
Your body needs a steady supply of vitamins, minerals and protein to produce energy.
Deficiencies in nutrients such as iron, vitamin B12, folate and vitamin D are well-recognised causes of fatigue.
Low magnesium intake may also contribute to poor sleep and muscle function, although deficiency is less common.
Blood sugar fluctuations
Skipping meals or relying on refined carbohydrates can lead to rapid rises and falls in blood glucose.
These fluctuations may contribute to energy crashes, poor concentration and increased food cravings.
Balancing meals with protein, fibre and healthy fats can help support steadier energy throughout the day.
Gut health
Many people are surprised to learn that digestive health may influence energy.
Poor gut health can affect nutrient absorption, immune function and communication along the gut-brain axis.
Digestive symptoms such as bloating, constipation or diarrhoea may suggest that addressing gut health could be an important part of improving overall wellbeing.
Inflammation
Low-grade chronic inflammation has been linked with fatigue in several long-term health conditions.
Inflammatory chemicals released by the immune system can affect brain function, mood and energy regulation.
An anti-inflammatory diet cannot eliminate fatigue, but it may help reduce one source of physiological stress.
Nutritional strategies to support energy
There isn’t a single “fatigue diet”, but several dietary habits consistently support healthy energy production.
Eat enough protein
Protein provides amino acids needed to build enzymes, hormones and neurotransmitters involved in energy metabolism.
Aim to include a good-quality protein source with every meal, such as:
- eggs
- fish
- poultry
- yoghurt
- tofu
- beans and lentils
- nuts and seeds
Build balanced meals
Each meal should ideally contain:
- protein
- healthy fats
- fibre-rich vegetables
- wholegrain or minimally processed carbohydrates
This combination supports more stable blood sugar levels and helps sustain energy between meals.
Eat a colourful, plant-rich diet
Different coloured fruits and vegetables provide antioxidants and polyphenols that help protect cells from oxidative stress.
Aim for a wide variety of plant foods across the week, including herbs, spices, legumes, nuts and seeds.
Greater plant diversity is also associated with a healthier gut microbiome.
Stay hydrated
Even mild dehydration can affect concentration, physical performance and mood.
Water remains the best choice, while excessive caffeine may contribute to sleep disruption in some people.
Check for nutrient deficiencies
If fatigue is persistent, it’s worth discussing appropriate testing with your healthcare professional.
Important nutrients to assess may include:
- iron and ferritin
- vitamin B12
- folate
- vitamin D
- thyroid function
- blood glucose
- full blood count
Correcting an underlying deficiency is far more effective than taking supplements without evidence of need.
Lifestyle habits that make a difference
Nutrition works best alongside healthy lifestyle habits.
Prioritise sleep
Aim for:
- a consistent bedtime
- reducing screen exposure before bed
- limiting caffeine later in the day
- keeping the bedroom cool and dark
- establishing a relaxing bedtime routine
Keep moving
When you’re tired, exercise may feel impossible.
However, regular gentle movement often improves energy over time.
Walking, swimming, yoga, Pilates and resistance training can all support cardiovascular health, muscle strength and mood.
If you have ME/CFS, exercise advice is different and should be tailored by an experienced healthcare professional because post-exertional symptom exacerbation is a defining feature of the condition.
Manage stress
Stress management doesn’t eliminate life’s pressures, but it helps reduce the physiological impact on your body.
Mindfulness, breathing exercises, spending time outdoors, social connection and enjoyable hobbies can all support resilience.
Pace yourself
Many people with persistent fatigue fall into a cycle of doing too much on good days and crashing afterwards.
Learning to pace activities and build in recovery time often leads to more consistent energy levels.
When should you seek medical advice?
Persistent fatigue should never simply be dismissed as “getting older.”
It’s important to consult your GP if fatigue:
- lasts longer than several weeks
- is severe or worsening
- interferes with daily life
- is accompanied by weight loss, persistent pain, fever or night sweats
- develops suddenly without an obvious explanation
Investigating possible medical causes is an essential first step.
To summarise
Fatigue is a symptom, not a diagnosis.
Whether it’s linked to poor sleep, stress, menopause, digestive health, nutrient deficiencies or an underlying medical condition, your body is signalling that it needs support.
Rather than searching for a quick fix, focus on the foundations of health: nourishing food, restorative sleep, regular movement, stress management and identifying any underlying causes.
Small, consistent changes are often far more effective than dramatic overhauls, and they create the conditions your body needs to produce energy more efficiently over the long term.
If you’re experiencing persistent fatigue alongside digestive symptoms such as bloating, constipation or IBS, it’s worth exploring whether improving your gut health could be an important part of restoring your vitality.