Do I need more calories if I have a cold? Unpacking the age-old advice

January 3, 2026 •

4 min read

Did you know that when your immune system activates to fight an infection, it requires extra energy and increases your metabolic rate? This energy-intensive process is key to understanding the age-old question: do I need more calories if I have a cold?

Quick Summary

Your body burns extra calories when fighting a cold to fuel its immune response. While a mild cold's effect on calorie needs is small, it is vital to focus on nutrient intake to aid recovery, not force yourself to eat.

Key Points

Increased Calorie Burn: Your body's immune response requires more energy, leading to a higher metabolic rate and increased calorie burn, especially with a fever.
Feed the Illness: The traditional saying "feed a cold, starve a fever" is outdated; consuming nutritious foods is important for both colds and fevers to fuel the immune system.
Listen to Your Appetite: If your appetite is low, don't force large meals. Focus on small, frequent, nutrient-dense foods and stay hydrated.
Prioritize Hydration: Drinking plenty of fluids is critical, as illness can cause dehydration and fluids can provide important calories and electrolytes.
Nutrient-Dense is Best: Focus on foods rich in vitamins, minerals, and protein to support immune function, not just high-calorie junk food.
Tapping Reserves is Normal: For short-term illnesses, your body can effectively tap into its energy reserves, so a few days of lower food intake is not detrimental to recovery.
Avoid Sugary Overload: While you may crave sugar for a quick energy boost, overconsumption can increase inflammation and potentially impede recovery.

The Immune System's Energy Demands

When a cold virus enters your body, your immune system launches a full-scale response. This process is not passive; it is highly active and requires a significant amount of energy to produce immune cells, antibodies, and inflammatory proteins. This heightened activity causes your metabolism to speed up, resulting in a higher caloric demand. While the extra calories burned are usually modest for a simple cold without a fever, they are still necessary to fuel the fight. If your food intake drops due to a suppressed appetite, your body will turn to its stored energy reserves, such as fat and muscle protein, to meet these demands. This is why eating well is important—to preserve muscle mass and support your immune function.

The "Feed a Cold, Starve a Fever" Myth

The traditional advice to "feed a cold and starve a fever" is largely considered outdated and unhelpful by modern medical experts. The truth is that both illnesses require your body to expend energy to fight the infection. A fever, in particular, elevates your body temperature, which further increases your metabolic rate and caloric needs. Fasting or severely restricting calories when you have a fever can be counterproductive, as your body needs fuel to power its defense mechanisms. Instead, the focus for both conditions should be on providing your body with adequate nutrients and, most importantly, staying well-hydrated.

Appetite and Hydration

A suppressed appetite is a common symptom when you're sick, driven by fatigue and inflammation. You should listen to your body's signals. If you're not hungry, you don't need to force yourself to eat large meals, as your body has reserves to tap into for a few days. However, staying hydrated is non-negotiable. Dehydration can hinder your body's healing process, and illnesses with fever or sweating can increase fluid loss. Nutrient-rich fluids like broths, herbal teas, and smoothies can provide both hydration and calories, which is an excellent strategy when solid food is unappealing.

How to Increase Nutrient-Dense Calories When You Have a Cold

When your appetite is low, the goal is to consume small, frequent meals or snacks that are both easy to digest and packed with nutrients. This provides a steady supply of energy without overwhelming your system.

Smoothies: A blend of fruit, yogurt or protein powder, and leafy greens can deliver vitamins, minerals, and calories in a single, easy-to-drink serving.
Soups and Broths: Warm liquids like chicken soup are hydrating, easy on the stomach, and provide electrolytes and calories. Adding lean protein and vegetables can increase the nutritional value.
Porridge: A warm bowl of oatmeal or rice porridge with honey or fruit is soothing and offers comforting carbohydrates for energy.
Yogurt and Probiotics: Plain yogurt contains probiotics that support gut health, which is closely linked to immune function. You can add a little honey or fruit for extra calories.
Easy Proteins: Scrambled eggs or poached fish are gentle on the digestive system and provide essential protein for muscle preservation.

Comparison: Mild Cold vs. Fever Calorie Needs


Feature	Mild Cold	Fever	Key Considerations
Metabolic Rate	Slightly elevated due to immune system activity.	Significantly elevated (approx. 7% per 0.5°C rise).	Fever drastically increases the body's energy expenditure.
Appetite	Often suppressed, but can vary.	Frequently suppressed due to intense immune response.	Listen to your body and focus on nutrient-rich fluids if not hungry.
Calorie Focus	Maintain normal calorie intake if possible, prioritizing nutrient density.	Replenish lost calories more actively due to increased energy burn.	Focus on consuming calories, especially from hydrating sources.
Primary Goal	Support immune function and prevent nutrient deficiency.	Provide adequate fuel to maintain metabolic processes and combat higher energy demands.

The Role of Macronutrients and Micronutrients

While calories provide the raw energy for your body to fight illness, the type of fuel is also important. Protein is vital for producing immune cells and antibodies, and adequate intake helps prevent muscle breakdown during sickness. Healthy fats are necessary for cellular repair, and carbohydrates offer a quick energy source. Crucial micronutrients like Vitamin C, Vitamin D, and Zinc are depleted faster when you're sick and play a direct role in immune function. Therefore, choosing whole, nutrient-dense foods over highly processed, high-sugar alternatives is essential for effective recovery.

Conclusion

In short, the answer to "do I need more calories if I have a cold?" is a nuanced "yes," but not in the way many people think. Your body's immune system does require extra energy to function, meaning your calorie needs increase slightly even with a mild cold. However, the exact amount is highly dependent on the severity of your symptoms, especially if a fever is present. The key takeaway is not to overeat, but rather to ensure that you are providing your body with a steady supply of nutritious food and, critically, ample fluids. Listen to your body, opt for easily digestible, nutrient-rich meals, and remember that consistent hydration is your most powerful ally in speeding up recovery. For more on the complex relationship between calories and immune function, read this informative research matters post from the National Institutes of Health.

Frequently Asked Questions

It's generally okay to eat less if your appetite is suppressed. For short-term illnesses, your body can use its energy reserves. The most important thing is to stay well-hydrated and consume nutrient-rich fluids if solid food is unappealing.

Good options include clear broths, soups, rice porridge, smoothies with fruit and yogurt, scrambled eggs, and well-cooked vegetables. These foods are gentle on the stomach and provide important nutrients.

Yes. A fever significantly increases your body's metabolic rate and calorie expenditure as it works to raise your core temperature. A mild cold without a fever increases calorie burn, but the effect is much less pronounced.

If you're not hungry for solid food, opt for calorie-rich drinks. Good choices include smoothies, milkshakes, and nutrient supplements. Broths and herbal teas with honey are also good, hydrating options.

Yes, having your favorite comfort food can lift your mood and provide a much-needed morale boost. However, avoid relying solely on high-sugar, highly processed options, as they can increase inflammation. Prioritize nutrient-dense foods when possible.

For a short-term illness, any slight increase in calorie intake is unlikely to cause lasting weight gain, as your body is burning extra energy to recover. The key is to consume nutritious calories, not excessive amounts of junk food.

Yes, chicken soup is often a great choice. It's hydrating, contains electrolytes, and provides nutrients and protein that help fuel the immune system. The warmth and steam can also help soothe a sore throat and relieve congestion.