When you’re sick with the flu, your body burns more calories fighting the infection while your appetite drops and your stomach rebels. The best strategy is to focus on easy-to-digest, nutrient-rich foods and plenty of fluids. Every degree of fever raises your metabolic rate by roughly 10%, so even when eating feels like a chore, getting some calories and protein in matters more than you might think.
Why Eating Matters When You Have No Appetite
A fever of just one or two degrees above normal increases your body’s energy demands by 10 to 20%. That extra fuel has to come from somewhere. If you’re not eating, your body breaks down muscle tissue for energy, which slows recovery and leaves you feeling weak long after the fever breaks.
During an acute infection, your protein needs jump by about 20 to 25% above what you’d normally require. For most adults, that means aiming for roughly 1 gram of protein per kilogram of body weight each day instead of the usual 0.8 grams. You don’t need to obsess over the math. Just make sure you’re getting some protein at every meal, even if “meals” are small and frequent.
Chicken Soup Earns Its Reputation
Chicken soup isn’t just comfort food. Lab research published in the journal Chest found that traditional chicken soup significantly slowed the movement of white blood cells called neutrophils, and it did so in a dose-dependent way. That matters because neutrophils rushing to the site of infection are a major driver of the congestion, sore throat, and general misery you feel with a respiratory illness. By calming that inflammatory response, chicken soup may genuinely ease upper respiratory symptoms.
Beyond the anti-inflammatory effect, soup checks several practical boxes at once. The broth delivers fluids and sodium. The chicken provides protein. The vegetables add vitamins. And the warm steam helps loosen congestion in your nose and chest. Homemade is ideal, but store-bought broth works when you’re too wiped out to cook.
Best Foods for an Upset Stomach
The old BRAT diet (bananas, rice, applesauce, toast) is fine for the first day or two of nausea or vomiting, but Harvard Health notes there’s no reason to limit yourself to just those four foods. A broader range of bland, easy-to-digest options gives your body the nutrients it actually needs to recover:
- Oatmeal provides soluble fiber and steady energy without irritating your stomach.
- Boiled or baked potatoes (without heavy toppings) are starchy and gentle.
- Crackers and dry cereal can settle nausea when you can’t face a full meal.
- Cooked carrots, butternut squash, or sweet potatoes add vitamins A and C in a soft, digestible form.
- Eggs are one of the easiest ways to get protein when chewing feels like too much effort. Scrambled or soft-boiled works well.
- Skinless chicken or turkey provides lean protein without the fat that can worsen nausea.
- Avocado offers healthy fats and potassium and goes down smoothly.
Start small. A few bites every couple of hours is better than forcing a full plate and triggering more nausea.
Honey for Coughs and Sore Throats
If a persistent cough is keeping you up at night, honey is worth reaching for. A systematic review in BMJ Evidence-Based Medicine found that honey performed about as well as the most common over-the-counter cough suppressant for reducing cough frequency and severity. It also outperformed another common antihistamine-based cough remedy on all symptom measures.
A spoonful of honey straight, or stirred into warm water or tea, coats the throat and can make nighttime coughing more manageable. One important note: honey should never be given to children under one year old due to the risk of botulism.
Fluids Are as Important as Food
Fever, sweating, and breathing through your mouth all pull water out of your body faster than normal. Baseline fluid needs are already substantial: roughly 11.5 cups (2.7 liters) a day for women and 15.5 cups (3.7 liters) for men, according to the U.S. National Academies of Sciences. When you’re running a fever, you need even more than that.
Plain water is the foundation, but it’s not the whole picture. You lose electrolytes through sweat, and replacing them helps your body absorb and retain the fluids you’re drinking. Good options include:
- Broth-based soups for sodium and potassium
- Oral rehydration drinks or diluted sports drinks for a balanced electrolyte mix
- Coconut water for potassium without added sugar
- Herbal tea with honey for warmth, fluids, and throat relief in one cup
Sip steadily throughout the day rather than trying to drink large amounts at once, especially if your stomach is sensitive. If your urine is dark yellow, you need more fluids.
Zinc Can Shorten Your Illness
Zinc lozenges, taken early in a respiratory infection, can shorten symptom duration by roughly two days. Research from the University of Helsinki found that both common forms of zinc lozenges were equally effective, and that doses above about 80 to 92 milligrams of elemental zinc per day didn’t provide additional benefit. Higher megadoses aren’t better, so stick to the amount listed on the package.
You can also get zinc from food. Shellfish, red meat, pumpkin seeds, chickpeas, and yogurt are all good sources. Zinc from food won’t deliver the concentrated dose of a lozenge, but it contributes to the overall picture, especially if you keep eating zinc-rich foods throughout your recovery.
Probiotic Foods and Gut Health
Your immune system is deeply connected to your gut, and the flu (plus any medications you take during it) can disrupt your gut bacteria. A randomized controlled trial found that probiotic supplementation shortened the duration of respiratory illness episodes by about 21%, cutting roughly two days off the average cold. Symptom severity dropped as well, and participants showed higher counts of the immune cells responsible for fighting viral infections.
Yogurt with live cultures is the easiest food-based source. Kefir, miso soup, and fermented vegetables like sauerkraut or kimchi also deliver beneficial bacteria. If dairy upsets your stomach during illness, kefir is often better tolerated than milk because the fermentation process breaks down much of the lactose.
Garlic for Immune Support
Garlic contains sulfur compounds that show antiviral activity in lab studies, working through several mechanisms including blocking viral entry into cells. The catch is that most of the research is preclinical, meaning it’s been tested in cell cultures and animal models rather than in large human trials. Still, garlic is a nutrient-dense food that adds flavor to soups and broths when everything tastes bland from congestion. Crushing or chopping garlic and letting it sit for 10 minutes before cooking activates more of its beneficial compounds.
What to Avoid While You’re Sick
Some foods actively work against your recovery. Large amounts of sugar can temporarily suppress immune function. Research suggests that consuming around 75 grams of sugar (roughly the amount in two cans of regular soda) weakens white blood cell activity for about five hours afterward. That’s a significant window when your immune system is already stretched thin fighting the flu.
Other foods to limit or skip:
- Alcohol dehydrates you and disrupts sleep quality, both of which slow recovery.
- Greasy or fried foods are hard to digest and can worsen nausea.
- Dairy doesn’t actually increase mucus production (that’s a myth), but thick, creamy foods can feel unpleasant in the throat when you’re already congested.
- Caffeine in large amounts acts as a mild diuretic and can interfere with the rest your body desperately needs. A single cup of tea is fine. Multiple cups of coffee are not ideal.
A Simple Day of Eating With the Flu
When you’re foggy and exhausted, even deciding what to eat feels overwhelming. Here’s a rough template. In the morning, try oatmeal made with water, topped with a drizzle of honey and a sliced banana. Mid-morning, sip on warm broth. For lunch, have a bowl of chicken soup with soft vegetables. In the afternoon, snack on crackers with a bit of avocado or scrambled eggs. For dinner, try rice with baked sweet potato and a small portion of plain chicken or fish. Between meals, keep a water bottle or mug of herbal tea within arm’s reach.
The portions can be tiny. What matters is eating something every few hours to give your body the protein, calories, and micronutrients it needs to fight the virus and rebuild once the worst has passed.