When you’re sick, your body burns more calories fighting infection, and the right foods can ease symptoms while keeping your energy up. What you should eat depends on whether you’re dealing with a respiratory illness like a cold or flu, or a stomach bug with nausea and vomiting. Here’s what actually helps, based on evidence rather than tradition.
Why Eating Matters When You’re Sick
A fever raises your metabolic rate, meaning your body burns through calories faster than usual with every degree your temperature climbs. Skipping meals might feel easier when you have no appetite, but going without food for too long deprives your immune system of the fuel it needs to mount a defense. The goal isn’t to force down a full meal. It’s to choose foods that are easy to tolerate, provide real nutrition, and in some cases actively reduce your symptoms.
Best Foods for Colds and Respiratory Illness
Chicken soup deserves its reputation. Researchers have found that hot chicken soup increases the speed at which mucus moves through your nasal passages, which helps clear congestion more effectively than hot water alone. The combination of warm broth, protein from the chicken, and vegetables gives you fluids, electrolytes, and calories in a form that’s easy to get down when your throat is raw. An aromatic compound in the soup appears to be responsible for the nasal-clearing effect, so homemade versions with onion, garlic, and herbs may work better than plain broth.
Citrus fruits, bell peppers, strawberries, and other foods rich in vitamin C won’t prevent a cold, but regular intake does slightly shorten how long one lasts: about 8% shorter in adults and 14% shorter in children. That translates to roughly half a day less of misery for an average cold. The benefit comes from consistent intake rather than megadosing once symptoms start.
Honey is one of the most effective natural cough suppressants available. Half a teaspoon to one teaspoon (2.5 to 5 milliliters) can calm a cough in children ages 1 and older. It works for adults too, stirred into warm tea or taken straight. Never give honey to a baby under 12 months due to the risk of infant botulism.
Foods high in zinc, like beef, shellfish, pumpkin seeds, and lentils, support immune function. Zinc lozenges specifically have been studied for colds: when people took lozenges delivering more than 75 mg of zinc per day, cold duration dropped by 20% to 42% depending on the type of zinc used. Zinc acetate lozenges showed the strongest effect at 42%. Below 75 mg per day, no benefit was found in any trial. To get the most from zinc lozenges, start them within the first day or two of symptoms.
Best Foods for Nausea and Stomach Bugs
Ginger is the most well-studied natural remedy for nausea. Clinical trials have tested doses ranging from 500 mg to 1,500 mg per day, typically divided into smaller portions taken throughout the day. In practical terms, that’s a thumb-sized piece of fresh ginger steeped in hot water for tea, or a few cups of real ginger ale (check the label for actual ginger, as many brands use only flavoring). Ginger chews and ginger capsules also work. Spacing your intake across the day is more effective than one large dose.
When nausea and vomiting are the main problem, start with small sips of clear fluids: water, diluted juice, or an electrolyte drink. Once you can keep liquids down, move to bland, easy-to-digest foods. Crackers, plain rice, toast, and bananas are all gentle options. Applesauce and oatmeal provide some fiber without being harsh on your stomach.
The BRAT Diet Is Outdated
For years, the standard advice for stomach illness was the BRAT diet: bananas, rice, applesauce, and toast. This is no longer recommended as a strict regimen. The American Academy of Pediatrics considers it too restrictive for children, noting it lacks protein, calcium, vitamin B12, and fiber. Following it for more than 24 hours may actually slow recovery by depriving your gut of the nutrients it needs to heal.
BRAT foods are fine as part of your diet for a day or two at the worst of your illness, but you should branch out as soon as you can tolerate it. Add in lean protein like chicken or eggs, cooked vegetables, and yogurt. The idea is to eat a wider range of gentle foods rather than limiting yourself to four items.
Milk and Dairy Don’t Make Congestion Worse
One of the most persistent food myths during illness is that dairy products increase mucus production. This has been tested multiple times, and it’s not true. Drinking milk does not cause your body to produce more phlegm. What does happen is that milk mixes with saliva to create a slightly thick coating in your mouth and throat, which can feel like mucus. It’s a sensory trick, not an actual increase in congestion.
Studies in children with asthma found no difference in symptoms whether they drank dairy milk or soy milk. So if yogurt, warm milk, or cheese sounds appealing when you’re sick, there’s no medical reason to avoid them. Yogurt with live cultures may even help by supporting the balance of bacteria in your gut, which is especially useful if a stomach bug has disrupted your digestion.
Fluids Are as Important as Food
Dehydration is one of the biggest risks when you’re sick, whether from fever, sweating, vomiting, or diarrhea. Water is the baseline, but you also lose electrolytes like sodium and potassium that plain water doesn’t replace. Broth-based soups cover both fluids and electrolytes naturally. Coconut water, diluted fruit juice, and oral rehydration solutions are other good options.
Warm liquids have an added benefit for respiratory illness. Hot tea, broth, and warm water with lemon and honey help loosen congestion and soothe a sore throat. Cold or room-temperature drinks are fine for hydration, but warm ones do more to relieve upper airway symptoms.
Foods to Avoid
Some foods make symptoms worse or are harder for your body to process when it’s already under stress. Greasy, fried, or heavily spiced foods can aggravate nausea and are harder to digest. Alcohol dehydrates you and suppresses immune function. Caffeine in large amounts also contributes to dehydration, though a single cup of tea or coffee is unlikely to cause problems.
Very sugary foods and drinks, like candy or full-strength soda, can worsen diarrhea by drawing water into the intestines. If you’re dealing with a stomach bug, stick with lower-sugar options or dilute fruit juices by half with water. Raw vegetables and high-fiber foods like whole grains are nutritious when you’re healthy, but they can be rough on an inflamed digestive tract, so save them for when your symptoms are improving.