Do you need to eat more when sick? Understanding the nutrition your body truly needs

October 12, 2025 •

4 min read

When your body is fighting an infection, its energy needs can increase by up to 10%, but your appetite may drop dramatically. So, do you need to eat more when sick? The answer is less about quantity and more about quality, focusing on easily digestible, nutrient-dense foods to support your immune system's hard work.

Quick Summary

This article explores the nutritional requirements during illness, debunking the old adage 'feed a cold, starve a fever'. It outlines the importance of hydration, the best foods to eat when your appetite is low, and which items to avoid for a faster recovery.

Key Points

Prioritize Hydration: Drinking plenty of fluids, such as water, broths, and herbal teas, is more critical than eating solid food during the initial stages of sickness, especially with a fever.
Focus on Nutrient-Dense Foods: When your appetite is low, choose small, frequent portions of easily digestible, nutrient-rich foods like soups, oatmeal, and yogurt to provide your body with the energy needed to fight infection.
Avoid Sugary, Fatty, and Spicy Foods: These items can worsen symptoms like inflammation, nausea, and dehydration, hindering your recovery.
Don't Force Yourself to Eat: If you have no appetite, listen to your body and focus on fluids. Forcing large meals can cause discomfort.
Tailor Your Approach to Symptoms: For stomach issues, bland foods like the BRAT diet may help, while warm broths and teas can soothe a sore throat and clear congestion.
The 'Feed a Cold, Starve a Fever' Myth is False: Your body needs nutrition to fight both colds and fevers. The strategy should focus on quality and hydration, not starvation.

For centuries, the phrase 'feed a cold, starve a fever' has guided people's eating habits during illness, but modern science has revealed that this advice is largely inaccurate. Regardless of the specific ailment, your body requires fuel to mount an effective immune response. The key is understanding that your approach to eating should adapt to your symptoms and appetite, prioritizing nutrients and hydration over forcing large meals.

The body's needs during illness

When you're sick, your body works overtime to fight infection. A fever, for example, raises your body's temperature, which speeds up your metabolism and burns more calories. This increased metabolic rate means your energy and nutrient requirements actually go up, not down. Simultaneously, the immune system releases cytokines, which can suppress your appetite, making it challenging to consume enough food. This creates a natural conflict: your body needs more fuel, but it doesn't want it. The strategy, therefore, should be to provide easy-to-digest, nutrient-rich foods that can be consumed in small, frequent portions.

Prioritizing hydration

Before you even think about solid food, hydration is the top priority, especially with a fever, vomiting, or diarrhea. Staying hydrated helps to regulate body temperature, flush toxins, and keep mucus thin, which can relieve congestion. While plain water is essential, your body also loses crucial electrolytes (like sodium and potassium) through sweating and other fluid loss.

Good sources of rehydration:

Broths and soups: Not only do they hydrate, but they also provide electrolytes and nutrients that are easy on the stomach. Chicken soup, in particular, contains anti-inflammatory properties.
Coconut water: A natural source of electrolytes.
Herbal teas: Warm tea can help soothe a sore throat and act as a natural decongestant. Add honey for extra antimicrobial benefits, but avoid giving it to infants under one year old.
Oral rehydration solutions: Over-the-counter options can quickly replace lost fluids and minerals.

The best foods when you have no appetite

If you have a limited appetite, focus on consuming nutrient-dense calories that are easy to digest. Bland, soft foods are often best to prevent further stomach upset.

BRAT diet foods: Bananas, rice, applesauce, and toast are bland and low in fiber, which can be helpful if you're experiencing diarrhea or nausea. However, this diet lacks key nutrients, so only follow it for a day or two.
Oatmeal: A gentle, comforting option that provides calories, vitamins, and minerals.
Greek yogurt: Contains probiotics that can support gut health, where a significant portion of your immune system resides. It's also a good source of protein.
Avocados: Rich in healthy fats, fiber, and vitamins, they are soft and easy to eat.
Soft-cooked eggs: A great source of protein and vitamin D.

Foods to avoid during illness

Just as important as knowing what to eat is knowing what to avoid, as certain foods can exacerbate symptoms or place extra strain on your body.

Sugary foods and drinks: While they provide a quick energy boost, sugar can promote inflammation and may suppress immune function.
Caffeine and alcohol: These are dehydrating and can interfere with the immune system.
Greasy and fried foods: Hard to digest and can worsen symptoms like nausea.
Spicy foods: Can irritate an upset stomach, though some find a small amount can help with congestion.
Acidic fruits and juices: While oranges have vitamin C, the acidity in some juices can irritate a sore throat or upset a sensitive stomach.

Comparison: Eating habits with a cold vs. fever


Aspect	Eating with a Cold	Eating with a Fever
Energy Needs	Can be normal or slightly elevated.	Elevated metabolism increases calorie needs to fight infection.
Appetite	Often diminished, but may be less severe than with a fever.	Typically suppressed due to immune system chemicals.
Fluid Importance	Crucial for hydration and thinning mucus.	Extremely important to replace fluids lost through sweating.
Focus Foods	Broths, teas, and nutrient-dense fruits and vegetables rich in vitamin C and antioxidants.	Light, hydrating, and easy-to-digest foods. Think soups, fruits, and broths.
Key Takeaway	Eat regularly as your appetite allows to maintain energy and hydration.	Hydration is paramount. Don't force yourself to eat if you have no appetite, but make small, nutrient-dense choices when you can.

Conclusion: Listen to your body

Ultimately, the question of whether you need to eat more when sick depends on your body's signals. Your immune system requires fuel to function, so depriving your body of nutrients can prolong recovery. However, forcing yourself to eat when you have no appetite can cause further discomfort. The best approach is to prioritize fluids, listen to your hunger cues, and choose small, frequent portions of nutrient-rich, easily digestible foods. As you begin to recover, your appetite should return, and you can gradually increase your food intake to replenish any lost nutrients and weight. If your appetite doesn't return, or your symptoms worsen, consult a healthcare provider. For most illnesses, the path to recovery is paved with proper hydration, rest, and mindful nutrition.

For more information on managing your diet during illness, visit:

Healthline: The 15 Best Foods to Eat When You're Sick (https://www.healthline.com/nutrition/15-best-foods-when-sick)

Frequently Asked Questions

No, you should not force yourself to eat large meals if you have no appetite. Instead, focus on staying hydrated with fluids like water, broth, or tea. When you do feel ready to eat, start with small, frequent portions of easy-to-digest foods.

The saying 'starve a fever' is a myth. A fever actually increases your body's metabolic rate, meaning it burns more calories and needs energy to fuel the immune response. While your appetite might be low, you should aim for small, nutrient-rich foods and prioritize hydration.

The best drinks are those that provide hydration and electrolytes. Water, broths, coconut water, and herbal teas are excellent choices. Avoid caffeinated drinks, alcohol, and sugary juices, as they can contribute to dehydration.

Yes, chicken soup is beneficial for several reasons. It provides hydration, electrolytes, and nutrients that are gentle on the digestive system. The warmth can also help clear nasal congestion, and chicken contains the amino acid cysteine, which has potential antiviral effects.

You should avoid sugary foods, fatty and fried foods, caffeine, and alcohol. These can worsen inflammation, lead to dehydration, and put extra stress on your digestive system, hindering recovery.

Yes, probiotic-rich foods like yogurt can help support your gut health. Since a significant portion of your immune system resides in your gut, maintaining a healthy gut microbiome can assist in fighting off illness.

You should contact a healthcare provider if your appetite doesn't return after a few days, or if you experience concerning symptoms such as struggling to eat or drink due to a sore throat, new rashes, or confusion.