Long COVID remains a complex and often invisible condition. Patients experience symptoms such as extreme fatigue, exercise intolerance, shortness of breath, cognitive impairment, and a pervasive sense of exhaustion for months or even years after a SARS-CoV-2 infection. Because these symptoms are not always objectively detectable through conventional medical tests, patients are frequently told that “everything looks normal”, even though their daily lives remain severely restricted. This invisibility makes long COVID an under-recognised condition that urgently requires greater acknowledgement and improved care, particularly in light of initiatives such as De Warmste Week.
In Belgium, Prof. Dr Elisabeth De Waele, Head of Clinical Nutrition and Dietetics at UZ Brussels and lecturer at Vrije Universiteit Brussel (VUB), together with Drs Berenice Jimenez Garcia (VUB/UZ Brussels), are taking a leading role in addressing this challenge. They combine their expertise in nutrition, metabolism and rehabilitation within the UNLOCK project (Nutrition and LOComotoric Rehabilitation in Long COVID), a pilot study investigating how a personalised approach to nutrition and physical activity can support recovery.
Energy Deficiency as a Driver of Fatigue
The study shows that many patients with long COVID fail to consume sufficient energy and nutrients, further undermining their recovery. Jimenez Garcia stresses that this issue should not be underestimated. A substantial proportion of participants in the pilot study did not meet their basic energy requirements and exhibited disrupted eating patterns, which may contribute to the severe fatigue that limits their daily functioning.
Through systematic assessments of body composition, resting energy expenditure and dietary intake, the researchers were able to develop precise, individualised nutritional plans. Weekly consultations helped patients gradually move towards a personalised optimal dietary pattern that improved both the quantity and quality of their nutritional intake.
Physical Activity: Progressing Cautiously Without Setbacks
Alongside nutritional counselling, patients received a tailored rehabilitation programme. As physical exertion in long COVID can often exacerbate symptoms, the focus was on the gradual rebuilding of activity with careful attention to energy conservation. The aim was to help patients progress towards a more active lifestyle without triggering symptom relapse. This adapted programme was developed by Prof. David Beckwée (VUB) and Dr Stijn Roggeman.
At the start of the programme, the physical condition of the study group was significantly lower than that of the general population. The one-minute sit-to-stand test and other functional assessments confirmed that muscle strength and physical capacity were markedly reduced.
Encouraging Results
After twelve weeks, both the reference group and the intervention group showed improvement, with the difference between the groups continuing to increase after the intervention period. This was largely due to greater gains in the intervention group. For De Waele, these findings are meaningful:
“The personalised treatment programme proved to be feasible in the long COVID population. As a pilot study, UNLOCK is not designed to demonstrate definitive recovery, but the results are promising and reinforce the need for further research into a multidisciplinary approach to long COVID with longer follow-up.”
De Waele also emphasises that relatively small adjustments can already have a noticeable impact:
“There is currently no medication that cures long COVID. But ensuring that patients consume enough to meet their basic needs is something we have extensive experience with and can be implemented quickly. It may already help to reduce the debilitating fatigue. We are not there yet, and it may not be a solution for everyone, but these new insights are crucial.”
An Invisible Condition Requires Visible Care
The UNLOCK project demonstrates not only that an integrated treatment approach is feasible, but also that it is essential. By combining nutritional and rehabilitative care, the underlying physiological dysregulation—previously largely invisible—becomes more recognisable to healthcare professionals as well as to patients themselves.
Through their work, Jimenez Garcia and De Waele take an important step towards greater recognition of long COVID. Their findings show that recovery requires personalised care, multidisciplinary guidance and close attention to the individual circumstances of each patient. Long COVID is not merely a residual complaint after a viral infection, but a prolonged systemic dysregulation that demands sustained attention, research and specialised care.
More information
Prof. Elisabeth De Waele: secretariaat.klinischenutritie@uzbrussel.be | Tel. +32 2 476 33 44
Drs Berenice Jimenez Garcia (VUB/UZ Brussels): berenice.jimenezgarcia@uzbrussel.be | Tel. +32 2 474 96 24