Managing blood sugar in ME/CFS and Long Covid

Metabolic health is a key piece in the complex puzzle of ME/CFS and Long Covid. While there is no one-size-fits-all fix, stabilising blood sugar helps to reduce inflammation and supporting your mitochondria with good food, stress management, and gentle movement can make a difference to your overall health.

Here we describe what is meant by metabolic health, what can go wrong in these conditions and steps you can take to reduce high blood sugar and support your metabolism.

1. What is metabolism?

Metabolism refers to all the chemical reactions within a human being that convert food and drink into energy and materials needed for growth, reproduction and maintaining health.  Metabolism refers to the chemical reactions that keep our cells alive and functioning. It has two main sides:

• Catabolism -breaking down nutrients (like carbs and fats) to release energy

• Anabolism -using that energy to build and repair tissues or store it for later

Enzymes act as the body's biochemical machinery, speeding up these reactions. When this system gets out of balance, metabolic disorders can occur—affecting how efficiently your cells produce and use energy.

2. Faulty metabolism in ME/CFS and Long Covid

Research  shows that people with ME/CFS and Long Covid experience abnormalities in energy metabolism, particularly at the cellular and mitochondrial level.

In ME/CFS

• In ME/CFS, dysfunction in how amino acids, hormones, and lipids are processed appears common

• Studies suggest that patients may have difficulties converting carbohydrates into usable energy, forcing the body to rely more on fats or proteins - for example Hoel, 2021 found

• People with ME/CFS are also at increased risk of developing metabolic syndrome—a cluster of conditions including high blood sugar, insulin resistance, and cardiovascular issues

"It seems that both male and female CFS patients may have the same obstruction in carbohydrate metabolism to energy, but they may try to compensate differently,”

                                                                                                                                   Oystein Fluge

“When you find such extensive changes in the pattern of amino acids and lipids, it indicates that something is going on with the energy metabolism.”

                                                                                                                            Karl Tronstad

Diagram showing altered use of amino acids and fatty acids in ME/CFS (Hoel, 2021)

In Long Covid

A recent study by Menezes (2023) of over 200 patients found that those with more severe symptoms often had:

• Higher BMI

• Abnormal triglycerides

• Elevated HbA1c (a marker of long-term blood glucose)

• High ferritin levels

This suggests acute inflammation from the virus may disrupt insulin signalling and metabolic function.

Managing blood sugar in ME/CFS and Long Covid

It is really important to focus on managing your blood sugar when you have ME/CFS or Long Covid

• Energy levels

• Mood and mental clarity

• Hunger and cravings

• Sleep quality

• Hormonal balance

• Risk of chronic disease (including heart disease, Alzheimer’s, and depression)

Most of us have about 4 grams of sugar in our entire bloodstream at any one time. Eating high-carb or sugary foods causes a surge in blood sugar. Your pancreas releases insulin to push that sugar into cells. But big spikes—and the crashes that follow—can cause problems.

4. Glucose swings and fatigue

People with ME/CFS and Long Covid often deal with severe fatigue and unstable blood sugar could make this worse:

• Big blood sugar spikes and dips can drain your energy, trigger brain fog, and even worsen depressive symptoms

• Research shows fatigue and poor memory are linked to sharp rises and falls in blood glucose

• These dips can also lead to stronger food cravings and hunger—fuelling a cycle of overeating and more spikes.

5. Beyond Energy - why blood sugar stability matters

High or erratic blood glucose is also linked to:

• Poor sleep - glucose crashes at night can cause you to wake up suddenly

• Weakened immunity -high glucose levels impair immune defences

• Menopausal symptoms - higher insulin is associated with worse hot flashes and mood swings

• Skin health -acne and other skin issues improve when blood sugar stabilises

• Brain health - chronic high glucose is being studied as a contributor to Alzheimer's disease.

  
  

6. What you can do to improve blood sugar and metabolic health

You don’t need to be diabetic to benefit from keeping your blood sugar stable. Here’s how to start:

a) Optimise your diet

• Reduce intake of refined carbohydrates (white bread, sugary drinks, processed snacks)

• Focus on foods that don’t spike your blood sugar—such as non-starchy vegetables, protein, healthy fats, and whole foods

• Try to maintain glucose within a narrow range by spacing meals, avoiding snacking on high-sugar foods, and combining carbs with fat or protein

  
  

  

b). Monitor your response

If your your blood sugar to be high:

• Use a Continuous Glucose Monitor (CGM) or finger-prick test to track how different meals affect you

• Some tools like Freestyle Libre provide real-time data that can be eye-opening

c) . Try to reduce stress

Chronic stress raises cortisol, which interferes with insulin and raises blood sugar

Try:

• Deep breathing, yoga or meditation

• Gentle exercise

• Trying to improve sleep, although this is not always easy

• Reducing alcohol and caffeine if these are consumed

• Not being too hard on yourself!

d). Try to reduce inflammation

Inflammation—common in ME/CFS and Long Covid—worsens insulin resistance. Think about reducing inflammation through:

• Focusing on oral hygiene if this is an issue, or treating other inflammatory conditions

• Adopting an anti-inflammatory diet

• Managing autoimmune symptoms can help improve glucose regulation

  
  

e) Move your body—gently

Even if you’re energy-limited:

• A short walk after meals helps lower glucose spikes

• Gentle strength exercises help improve insulin sensitivity over time

• Always pace according to your energy envelope

Final Thoughts

Managing blood glucose levels may reduce the severity of some of symptoms such as fatigue and brain fog. Taking measures to manage blood glucose can also reduce long term health risks caused by  metabolic disease, including Type 2 diabetes and heart disease. Most important, try to reduce your intake of sugars and refined carbohydrates!