COVID-19 infection can cause unintended weight loss, both during the acute phase and into recovery. Understanding contributing factors is important for managing health during and after infection.
How COVID-19 Can Lead to Weight Loss
COVID-19 infection increases the body’s metabolic demand. The immune system’s inflammatory response burns more calories, even at rest. Fevers, a common symptom, further elevate this rate, leading to higher energy expenditure if caloric intake is insufficient.
Many COVID-19 symptoms interfere with adequate eating. Loss of taste and smell are common, making food unappealing. Gastrointestinal issues like nausea, vomiting, and diarrhea are prevalent, hindering nutrient absorption and appetite. Difficulty swallowing from a sore throat or respiratory distress can limit food intake.
The body experiences muscle breakdown, or catabolism, while fighting infection. This occurs when the body uses its own tissues, particularly muscle protein, for energy. This reduces lean body mass, contributing to overall weight loss. Many COVID-19 patients experience significant muscle loss.
Factors Contributing to Weight Loss During and After COVID-19
Beyond the virus’s immediate effects, indirect and longer-term factors contribute to weight loss, especially in “Long COVID” individuals. Extreme fatigue, a common symptom, makes everyday tasks like food preparation and eating difficult. Weakness and breathlessness also limit the capacity for adequate nutrition.
Psychological stress, anxiety, and depression are common during and after COVID-19, significantly impacting appetite and eating habits. Some individuals experience a reduced desire to eat, or disrupted eating patterns, leading to insufficient caloric intake. This emotional distress can create a cycle where poor appetite contributes to weakness and prolonged recovery.
Persistent “Long COVID” symptoms, including post-exertional malaise (worsening of symptoms after physical or mental effort) or chronic digestive issues, can hinder nutrient absorption and appetite. Gastrointestinal problems like constipation, food intolerance, and decreased appetite may persist for months, interfering with consistent food intake. Organ damage can impair nutrient absorption and alter metabolic processes, exacerbating nutritional deficits.
Reduced physical activity and prolonged immobility, whether from severe illness, hospitalization, or feeling unwell, contribute to muscle atrophy. Even short periods of reduced movement can lead to muscle shrinking and wasting. This loss of muscle mass, or sarcopenia, contributes to overall mass loss and can persist after acute infection resolves.
Addressing Weight Loss and Recovery
If you experience significant or unexplained weight loss, or persistent concerning symptoms after COVID-19, seek medical advice. A healthcare provider can assess the weight loss, rule out other conditions, and determine malnutrition risk. Prompt medical attention is also recommended if weight loss is rapid, continues after recovery, or is accompanied by severe fatigue or fever.
Nutritional strategies are important for regaining lost weight and supporting recovery. Consuming small, frequent, nutrient-dense meals every two to three hours can increase caloric and protein intake, even with diminished appetite. Focus on protein-rich foods like meat, fish, eggs, and dairy, along with energy-dense options, to rebuild muscle and provide needed calories. Adequate hydration is also essential, with recommendations to drink 2 to 3 liters of fluids daily.
A gradual, supervised return to physical activity is important for rebuilding strength and muscle mass. After acute illness, start with very low-intensity activities like flexibility and breathing exercises, slowly increasing duration and intensity over several weeks. Avoid strenuous activity, especially anything causing breathlessness, to prevent inflammation or worsening symptoms. Professional support, such as consulting a dietitian or physical therapist, can provide personalized guidance. A dietitian can help develop a tailored meal plan, and a physical therapist can guide a safe exercise program.