The saying "feed a cold, starve a fever" has been passed down for centuries, suggesting different dietary approaches depending on the illness. However, modern research shows that both colds and fevers increase the body's energy needs, making adequate nutrition important during any infection1 . While appetite often decreases during illness, the body still requires calories and fluids to support immune function and recovery2 . Understanding the origins and accuracy of this adage helps clarify how best to care for oneself when sick.
Feed a Cold, Starve a Fever: Origins and Accuracy
The phrase "feed a cold, starve a fever" dates back to the time of Hippocrates, who believed fever was a disease itself and that starving a patient with fever would starve the disease3 . Early interpretations varied, with some suggesting that eating during a cold would generate warmth, while avoiding food during fever would help cool the body4 . However, this adage is largely considered an old wives' tale without strong scientific backing2 .
A 2002 study in The Netherlands explored this concept but was too small to draw definitive conclusions3 . More recent expert opinions emphasize that the body needs energy to fight infections regardless of whether a person has a cold or a fever5 . The belief that fasting during fever is beneficial is not supported by evidence, and modern clinical guidelines recommend supportive care with adequate nutrition and hydration for both conditions6 7.
Fever is an evolutionarily conserved response that raises the body's metabolic rate by about 10-20%, increasing energy expenditure to enhance immune defense8 9. This metabolic increase means the body requires more calories, especially carbohydrates and fats, to support immune cell function and thermogenesis (heat production) during illness10 11. Therefore, "starving a fever" contradicts the physiological demands of the body during infection.
“It’s most likely ‘just an old wives’ tale,’ said Dr. David Schneider, chair of the department of family and community medicine at the University of Texas Southwestern Medical Center in Dallas.”
— Dr. David Schneider, University of Texas Southwestern Medical Center2
Nutritional Support for Colds and Fevers
During infections like colds and fevers, the body undergoes metabolic changes that increase energy needs. Fever raises metabolism by 10-20%, requiring additional calories to fuel immune responses and tissue repair8 1012. Sickness-associated anorexia, or reduced appetite during illness, is common and may serve an adaptive role in immune regulation, but it should not lead to malnutrition13 14.
Maintaining adequate nutrition and hydration supports immune function and helps the body recover more efficiently7 . While you may not feel hungry, it is important to consume fluids and nutrient-rich foods as tolerated. For those who cannot eat full meals, calorie-containing fluids can help meet energy needs7 .
Consume Fluids With Calories
Hydration is critical during both colds and fevers because symptoms like sweating, vomiting, and mucus production can cause fluid loss6 2. Drinking fluids that contain calories and electrolytes, such as coconut water or sports drinks, helps maintain energy and hydration1 . These fluids support mucosal barrier integrity, which is essential for immune defense against pathogens6 .
- Caloric and electrolyte-containing fluids help maintain energy and hydration during recovery7 .
- Staying hydrated thins mucus, making it easier to clear nasal passages and reduce congestion2 .
- Avoid alcohol and caffeinated drinks as they can worsen dehydration and inflammation1 .
- If appetite is low, prioritize fluids with calories over solid foods initially1 .
- Maintaining hydration supports physiological functions and immune defense6 .
Drink Hot Liquids
Warm beverages like herbal tea or broth provide soothing relief for sore throats and help keep mucus thin15 1. Chicken soup, a traditional remedy, offers hot liquids combined with electrolytes, antioxidants, and nutrients that support the immune system15 . The steam from hot drinks can also open sinus passages, easing congestion15 .
- Hot liquids help thin mucus, making it easier to expel15 .
- Broth and soup provide hydration, nutrients, and antioxidants15 .
- Herbal teas can soothe irritated throats and promote comfort1 .
- Warm fluids support mucosal barrier integrity and immune defense6 .
- Salt-water gargles may help clear mucus and ease throat irritation5 .
Foods and Drinks To Avoid
Certain foods and beverages may worsen inflammation or dehydration during illness. Limiting irritants and excessive sugars can support immune function and reduce discomfort16 17. Alcohol and caffeinated drinks should be avoided because they increase the risk of dehydration and may impair immune responses1 .
- Avoid alcohol and caffeinated drinks to prevent dehydration1 .
- Limit foods high in fat or added sugars to reduce inflammation16 17.
- Avoid irritants that may worsen throat or nasal symptoms16 .
- Focus on nutrient-rich, easily digestible foods to support recovery7 .
- Do not force eating if appetite is suppressed; focus on hydration first7 .
When to Seek Medical Care
While most colds and fevers can be managed with supportive care, certain symptoms require prompt medical evaluation. Persistent or worsening symptoms may indicate complications or more serious infections7 . People with underlying chronic illnesses are at higher risk for complications and should consult healthcare providers early7 .
Key signs to seek medical care include:
- High or prolonged fever lasting more than 48-72 hours or reaching 105°F7 .
- Neurological symptoms such as confusion or altered alertness7 .
- Respiratory distress or cyanosis (bluish discoloration of lips, nails, or tongue) 7.
- New or unexplained rashes or bruising during illness7 .
- Painful urination or other unusual symptoms7 .
- Recent international travel with fever, which may suggest exposure to infectious diseases7 .
- Severe headache, stiff neck, or seizures7 .
- Underlying conditions like diabetes, heart disease, lung disease, or immune suppression7 .
Maintaining nutrition and hydration during illness supports immune function and recovery, but if appetite does not return after a few days or symptoms worsen, medical advice is essential7 1.
Key Takeaways
- The adage "feed a cold, starve a fever" is an outdated belief with little scientific support; both colds and fevers increase energy needs2 3.
- Fever raises metabolism by 10-20%, requiring additional calories and fluids to support immune function8 1012.
- Hydration is critical during illness to replace fluids lost through sweating, vomiting, and mucus production6 2.
- Nutrient-rich foods and calorie-containing fluids help maintain energy and support recovery, but do not force eating if appetite is suppressed7 1.
- Seek medical care for high or prolonged fever, neurological symptoms, respiratory distress, new rashes, or if underlying health conditions increase risk7 .
