What to eat when you’re sick

There’s plenty of advice about what to eat when you’re feeling lousy. Many of us remember being given a steaming bowl of chicken soup as kids when home with a cold, or saltines and ginger ale for nausea. But is there any science behind these traditions?

When you’re sick, your body needs extra care to support optimal immune function. This means focusing on nutrient-dense meals, proper hydration, and gut health. Skipping meals or relying on empty calories won’t help the healing process. Here, we’ll break down science-based recommendations to help you recover quickly and get back to feeling your best.

Myths and idioms

The saying “feed a cold, starve a fever” dates back to a 16th-century dictionary and has been passed down as common advice for illness. The idea is that colds make you feel chilled, so eating warms you up, while fasting during a fever can help cool you down. However, this idiom has little scientific backing. Your body needs nutrients and energy to fight any illness, and restricting food can weaken the immune response and slow down recovery.

A similar misconception surrounds the use of the BRAT diet—bananas, rice, applesauce, and toast—for nausea. These bland foods are often recommended because they’re easy to digest. While gentle on the stomach, these options are often high in simple carbohydrates and can lead to a blood sugar spike and crash, which can worsen nausea and dizziness. They also often lack essential nutrients for healing. If you’re craving toast, a better option might be low-carb bread topped with nut butter and a small amount of sliced banana for protein, fat, and fiber. 

Physiology of common illnesses

When you catch a common cold virus, the body produces more mucus, and the blood vessels in your respiratory tract swell, both of which help trap and eliminate pathogens. However, this swelling and excess mucus lead to congestion that makes it harder to breathe. Warm liquids like soups and teas are helpful because they thin mucus, making it easier to breathe. Certain compounds like ginger and garlic can also be soothing: ginger’s gingerol and shogaol reduce cytokine activity (part of the body’s inflammatory response that can worsen congestion), while garlic’s allicin helps soothe inflammation and open nasal passages. Flavoring foods with spices like turmeric, which contains curcumin, may also be helpful, as curcumin has anti-inflammatory properties that can reduce congestion and support respiratory health. Staying hydrated supports the immune system by keeping mucus membranes moist and allowing your body to regulate its temperature.

Fevers raise your body’s temperature as a defense mechanism, which in turn speeds up metabolism, boosting immune responses like white blood cell activity to help fight off infections more effectively. This metabolic increase leads to faster protein breakdown, which means you need to ensure adequate intake to support tissue repair and immune function. Fever-associated sweating can also cause fluid loss. Clear bone broths are particularly helpful during fever because they provide both hydration and nutrients without putting strain on the digestive system. 

The processes of nausea and vomiting result from continuous interactions between the gastrointestinal tract, including its enteric nervous system, the CNS, and the autonomic nervous system. Compounds such as peppermint’s menthol, chamomile’s apigenin, and fennel’s anethole relax digestive muscles and ease symptoms. Sipping herbal tea or adding small amounts of fennel and ginger to meals can provide relief. 

Strategies to support your immune system

Certain micronutrients are key to an effective immune response. Vitamin C supports the production of white blood cells, while vitamin D regulates inflammation and reduces the risk of respiratory infections. Zinc helps maintain immune cell function and has been shown to shorten the duration of colds when taken early in an illness. Try a meal of steamed cauliflower (vitamin C) and salmon (vitamin D) with pumpkin-seed pesto (zinc) for a soothing, immune-boosting dinner. 

Be strategic with your macronutrients. It’s important to make sure you get enough protein, which provides essential building blocks for tissue repair and antibody production. Limited amounts of complex carbohydrates such as brown rice, sweet potatoes, and quinoa can soothe the stomach and lend fiber. You’ll want to limit heavy, greasy, or fried foods, as they can slow digestion and exacerbate nausea by further irritating the stomach. However, small amounts of healthy fats such as olive oil can keep you satiated and support the absorption of fat-soluble vitamins like A, D, E, and K, which are essential for overall health and immune function. Rather than toast and crackers, have a poached chicken breast with brown rice and green beans drizzled with a little bit of olive oil and lemon.

Live probiotics from fermented foods such as yogurt and kefir support a healthy gut, which is vital to a properly functioning immune system; approximately 70 percent of the body’s immune cells are found in the gastrointestinal tract. For prebiotics, mild options like bananas and oatmeal provide essential fibers to feed beneficial gut bacteria without overwhelming the digestive system during illness.

It’s important to avoid foods and drinks that can weaken your immune system or slow recovery. Traditional sick-day staples like ginger ale, crackers, and popsicles may provide familiarity and comfort. However, these processed foods tend to lack nutrients and be high in added sugar and refined carbohydrates, which can disrupt the balance of beneficial gut bacteria, worsen fatigue, and contribute to more inflammation. You’ll also want to limit alcohol, which can cause dehydration and disrupt sleep. 

The importance of proper hydration

Fevers, vomiting, and diarrhea deplete fluids fast. Make sure to get plenty of water, and supplement with other liquids such as herbal teas and broths. Tea contains antioxidants and anti-inflammatory compounds such as ginger and turmeric, while broths are often rich in minerals like calcium, magnesium, and potassium, as well as protein from collagen and amino acids.

It’s also important to make sure that you maintain normal electrolyte levels. Electrolytes are minerals like sodium, potassium, and magnesium that help regulate the body’s fluid balance, nerve function, and muscle contractions. Vomiting and diarrhea make you lose electrolytes, which can lead to symptoms like fatigue, dizziness, or muscle cramps. Instead of sugary drinks like sports drinks, which can worsen inflammation, choose natural sources such as coconut water or electrolyte drinks without added sweeteners. For a homemade electrolyte drink, try mixing ¼ teaspoon of Himalayan salt, 500 mg of potassium citrate powder, ¼ teaspoon of magnesium malate, and 8-16 oz of water. Another option is to combine 1 cup of coconut water, 1 cup of water, the juice of 1-1.5 limes, and 1/8 teaspoon of Himalayan salt.

Portion size and meal timing

You might not be able to handle large portions when you’re sick, especially if you’re experiencing nausea. Try small, frequent meals, which are easier on the GI tract and give you a better chance of absorbing key nutrients. Simple, nutrient-dense foods like soups, smoothies, and porridge can be consumed in small amounts while still providing essential vitamins and minerals.

A day of healthy eating when home with a virus might look like the following: Start off with a smoothie made from spinach, frozen berries, Greek yogurt, and a spoonful of nut butter. For lunch, try a simple vegetable soup with cooked carrots, greens, and shredded chicken for protein. In the afternoon, have a snack of baked sweet potato with cottage cheese. End the day with a light dinner of steamed zucchini, white fish, and millet. Try to have your last meal several hours before going to bed to support good sleep and digestion.

Conclusion

Making sure you prioritize proper hydration, electrolytes, and immune-supporting nutrients will reduce the severity of your symptoms and speed recovery. Water, herbal teas, and broths replenish lost fluids while aiding circulation and toxin removal. Getting electrolytes like sodium and potassium helps regulate fluid balance and maintain proper muscle and nerve function. Immune-boosting nutrients such as vitamin C, vitamin D, and zinc enhance the body’s ability to fight infection and reduce inflammation. Consuming easy-to-digest protein with complex carbs and healthy fats will keep you satiated and support balanced energy levels without overwhelming the GI system. By focusing on these strategies, you’ll give your body the support it needs to recover efficiently while minimizing discomfort.