When you have a fever, your body burns through calories and fluids faster than normal. Every degree your temperature rises increases your metabolic rate, meaning you need more energy at the exact moment you least feel like eating. The goal isn’t to force down a full meal. It’s to give your body enough fuel, fluids, and nutrients to support your immune system without overwhelming your stomach.
Why Eating Still Matters
The old saying “starve a fever” is wrong. A fever raises your body temperature, which speeds up your metabolism and burns more calories than usual. Your immune system is also working overtime, producing white blood cells and antibodies that require protein and energy to build. Skipping food entirely during a fever deprives your body of the raw materials it needs to fight the infection.
That said, your appetite will likely drop, and that’s normal. You don’t need to eat full portions. Small, frequent meals or snacks every few hours work better than trying to sit down for three square meals. The priority is getting something in rather than getting the perfect amount in.
The Best Foods During a Fever
Chicken soup earns its reputation. A study published in the journal CHEST found that chicken soup has a mild anti-inflammatory effect: it slows the movement of certain white blood cells that drive the congestion and inflammation you feel during upper respiratory infections. Both the chicken and the vegetables in the soup contributed to this effect individually, and the complete soup showed no harmful activity on cells. Broth-based soups in general are ideal because they deliver calories, sodium, and fluid all at once.
Beyond soup, focus on foods that are nutrient-dense but easy to digest:
- Eggs (scrambled or soft-boiled) provide protein without requiring much effort to eat or digest.
- Oatmeal offers steady energy from complex carbohydrates, plus some fiber.
- Bananas are rich in potassium, one of the key electrolytes lost through sweating and fever.
- Yogurt delivers protein and beneficial bacteria that support gut health, which can take a hit during illness.
- Cooked vegetables like carrots, sweet potatoes, and spinach are easier on the stomach than raw ones and provide vitamins your immune system uses.
- Toast with nut butter combines quick-digesting carbohydrates with protein and healthy fat.
If your fever comes with nausea or an upset stomach, you may have heard of the BRAT diet (bananas, rice, applesauce, toast). While these foods are gentle, major health organizations including the American Academy of Pediatrics and the CDC no longer recommend relying on them exclusively. The BRAT diet provides roughly 300 fewer calories per day than a normal diet and is extremely low in protein, fat, fiber, vitamin A, vitamin B12, and calcium. It simply doesn’t give your body enough to recover with. Use those foods as a starting point if nothing else sounds appealing, but add protein and fats as soon as you can tolerate them.
Fluids Are Non-Negotiable
Fever increases fluid loss through your skin even when you aren’t visibly sweating. Clinical guidelines suggest that for every degree of temperature above 100.4°F (38°C), your body’s fluid loss through the skin rises by about 10%. That adds up fast during a fever that lasts several days. Dehydration makes you feel worse, thickens mucus, and can slow recovery.
Water is the foundation, but it’s not the only thing you need. Fever depletes sodium, potassium, and calcium through sweat. Plain water alone won’t replace those. Good options include:
- Broth (chicken, beef, or vegetable) for sodium
- Oral rehydration solutions or electrolyte drinks for a balanced mix of minerals
- Coconut water for potassium
- Diluted fruit juice for calories and some vitamins
- Herbal tea (peppermint, ginger, or chamomile) for warmth and gentle stomach soothing
Aim to sip throughout the day rather than chugging large amounts at once, especially if nausea is an issue. A good rule of thumb: if your urine is dark yellow or you’re urinating much less frequently than normal, you need more fluid.
Foods and Drinks to Limit
Some things that seem harmless can actually work against you during a fever. Sugary foods and drinks deserve particular caution. There’s evidence that consuming large amounts of sugar can temporarily impair white blood cell function, essentially slowing down the immune cells you need most right now. Sports drinks, soda, and candy may give a quick energy boost but aren’t doing your immune system any favors. If you want something sweet, whole fruit is a better choice because it comes with fiber, water, and vitamins alongside the sugar.
Other foods worth avoiding or limiting:
- Alcohol is dehydrating and suppresses immune function.
- Caffeine in large amounts acts as a diuretic, increasing fluid loss. A small cup of tea is fine, but several cups of coffee will work against your hydration efforts.
- Greasy or fried foods are harder to digest and can worsen nausea.
- Heavy dairy (ice cream, rich cheese sauces) can feel heavier in your stomach, though plain yogurt and milk are usually fine.
- Highly spiced foods may irritate an already sensitive stomach, though mild spices like ginger and turmeric can actually help with inflammation.
What About Vitamin C and Zinc?
You’ll find no shortage of advice telling you to load up on vitamin C and zinc supplements when you’re sick. The reality is more nuanced. A clinical trial using high doses of both (8,000 mg of vitamin C and 50 mg of zinc daily) found that neither reduced the duration of illness symptoms. High-dose vitamin C also caused nausea, diarrhea, and stomach cramps in some participants, which is the last thing you want on top of a fever.
That doesn’t mean these nutrients are useless. Getting vitamin C and zinc through food, at normal dietary amounts, supports your immune system without the risk of stomach upset. Citrus fruits, bell peppers, strawberries, and kiwi are all rich in vitamin C. For zinc, lean toward eggs, yogurt, nuts, seeds, and legumes. You’ll get meaningful amounts without overwhelming your digestive system.
A Practical Eating Plan
When you’re feverish and exhausted, meal planning feels impossible. Keep it simple. A reasonable day of eating during a fever might look like this: a small bowl of oatmeal with banana in the morning, a cup of chicken soup with some crackers at midday, yogurt with berries in the afternoon, and scrambled eggs with toast in the evening. Between those, sip on broth, herbal tea, water, or an electrolyte drink steadily throughout the day.
If you truly cannot eat solid food, prioritize calorie-containing liquids: broth, smoothies blended with yogurt and fruit, or even warm milk with honey. Getting 50% of your normal caloric intake through liquids is far better than eating nothing. As your fever breaks and appetite returns, gradually increase portion sizes and variety. Most people find their hunger comes roaring back within a day or two of the fever resolving, and that’s the time to eat generously and rebuild what your body used up fighting the infection.