Have you ever opened your refrigerator or pantry and found that nothing looks appetizing? Or maybe you just don’t feel hungry at all lately? Appetite loss (also called decreased appetite) is a common side effect of cancer treatment. Kidney cancer itself can also lower your appetite.

Eating well is important for maintaining your weight — especially your muscle mass (the body’s strength-building tissue) — and keeping up your energy and strength during treatment.

In this article, we’ll explain why kidney cancer and its treatments can cause appetite loss. We’ll also cover how appetite loss may affect your overall health and share practical tips to help you maintain a healthy diet during treatment.

Why Appetite Loss Happens With Kidney Cancer and Its Treatment

Most people with kidney cancer don’t notice symptoms before diagnosis. However, some people do experience symptoms, including loss of appetite. In addition, cancer treatments can often cause side effects like decreased appetite.

Appetite Loss From Kidney Cancer

Kidney cancer develops when cells in the kidneys grow and divide too quickly. If not treated, these abnormal cells can form a tumor (a mass of cancer cells).

Some people with kidney cancer may develop paraneoplastic syndrome (conditions caused by the body’s response to cancer rather than the tumor itself). These syndromes can lead the immune system to damage healthy tissue as it tries to destroy the tumor. One possible symptom is loss of appetite.

Appetite Loss From Treatment

Several treatments are used for kidney cancer, and each one may affect your appetite in different ways.

Surgery

Surgery is a common treatment if kidney cancer hasn’t metastasized (spread) to other parts of the body. During surgery, a surgeon removes part or all of the kidney. After surgery, some people may develop an infection or feel generally unwell, which can reduce appetite.

In some cases, the remaining kidney or kidneys may not work as well as before, which can contribute to chronic kidney disease (CKD). CKD is a long-term condition where the kidneys don’t filter waste effectively. In advanced CKD, symptoms like loss of appetite, nausea, and vomiting can occur.

Targeted Therapy

Targeted therapy uses drugs to prevent kidney cancer cells from growing and spreading. Many of these drugs can cause side effects, including loss of appetite.

Additionally, other gastrointestinal (digestive) side effects are common, such as:

• Nausea
• Vomiting
• Taste changes
• Constipation
• Diarrhea

Some targeted therapy drugs may also cause hypogeusia (partial loss of taste) or dysgeusia (changes in taste). Dysgeusia can cause foods to taste metallic, salty, or less flavorful, which can make eating less appealing.

In one small study of drugs called tyrosine kinase inhibitors (TKIs), about two-thirds of participants reported taste changes or loss. About 42 percent of participants experienced mucositis (inflammation of the lining of the mouth and digestive tract), which can make eating painful.

Immunotherapy

Immunotherapy uses drugs to help your immune system better find and destroy cancer cells. Common side effects include appetite loss, nausea, and diarrhea.

Like targeted therapy, immunotherapy can sometimes cause taste changes or mucositis. However, these side effects may happen less often with immunotherapy than with targeted therapy.

Radiation Therapy

Radiation therapy uses high-energy rays to destroy cancer cells or shrink tumors. It can also cause side effects such as nausea and diarrhea, which may make it harder to eat.

How Appetite Loss Affects Your Health During Treatment

Cancer and its treatments can increase your body’s energy needs. However, appetite loss may make you feel like eating less or not at all.

When you lose your appetite, you may notice that you are:

• Eating less than usual, or not eating at all
• No longer interested in your favorite foods
• Less interested in food overall

Over time, eating less can lead to weight loss. This may leave you feeling weak, tired, and less able to recover from treatment.

Good nutrition helps your body heal, maintain strength, and lower the risk of infection. Without enough nutrients, it may be harder to complete your cancer treatments.

Appetite loss can also contribute to a condition called cachexia (wasting syndrome). Cachexia involves ongoing weight loss, including loss of muscle and body fat.

Cachexia may be diagnosed when a person loses more than 5 percent of their body weight over six months or more than 10 percent overall. This can happen when the body does not get enough calories to meet its needs, along with cancer-related metabolic changes (how the body uses energy differently, often leading to faster breakdown of muscle and fat).

Let your cancer care team know right away if you:

• Are unable to eat or have been vomiting for 24 hours or more
• Aren’t urinating for a full day or your urine looks very dark
• Have lost 3 pounds or more in a week
• Can’t keep liquids down

Loss of appetite can affect your quality of life, so it’s important to talk openly with your cancer care team about any changes you notice. They can help you find ways to manage this symptom.

Strategies To Eat Well When You Don’t Feel Like Eating

While loss of appetite is common with cancer and its treatments, good nutrition can help you manage its effects. Here are some tips that can help you get the nutrition you need, even when you don’t feel like eating.

Work With a Dietitian

A registered dietitian (RD or RDN) is a healthcare professional who specializes in nutrition. They can help you create a meal plan and show you practical ways to eat well during treatment.

A dietitian who is trained in kidney health can help create a meal plan that fits your needs.

For example, people with reduced kidney function or those on dialysis (a treatment that filters waste from the blood) may have different nutritional needs, such as adjusting protein, fluid, or certain minerals.

Have Easy, High-Protein Snacks on Hand

Good nutrition can support your body during kidney cancer treatment and recovery. Eating well helps you maintain your weight and keep up your strength.

Your body needs protein to support your immune system and repair tissues. People with cancer often need more protein than they did before diagnosis.

Healthy sources of lean protein include:

• Fish
• Skinless chicken
• Beans
• Lentils
• Tofu
• Eggs

Keeping easy, ready-to-eat high-protein snacks on hand can make it easier to eat when your appetite is low. Good options include nuts, nut butters (such as peanut butter), yogurt, hummus, cheese and crackers, and premade soups.

Fruits, vegetables, and whole grains also provide important vitamins and minerals.

Try to limit salt and highly processed foods, as they can increase fluid retention (swelling) and raise blood pressure.

Eat Small Meals or Snacks Regularly

If you’ve lost your appetite, eating smaller meals or snacks more often throughout the day may feel easier than trying to eat three large meals. You don’t have to follow a strict schedule. Try to eat whenever you feel hungry.

If you feel nauseated or have pain, taking your prescribed medications about 30 minutes before eating may help make meals more comfortable. Always follow your doctor’s instructions.

If you have favorite foods, eat them whenever they sound appealing, even if it’s not a typical mealtime.

Tailor Strategies to Your Symptoms

You can try different eating strategies based on how you’re feeling:

• If you’re feeling nauseated, soft and easy-to-digest foods — such as smoothies — may be easier to tolerate.
• If you notice changes in taste or a loss of taste, try adding herbs, marinades, or spices to improve flavor.
• If food smells bother you, eating cold or room-temperature foods may help reduce strong odors.

Stay Hydrated

Staying well hydrated is important for your overall health. Proper hydration may help reduce some treatment side effects.

If you’re having trouble drinking enough fluids, you can:

• See whether warm or cold beverages are easier for you to drink.
• Suck on ice chips or a popsicle if drinking feels difficult.
• Add fruit (such as berries or lemon), cucumber, or mint to enhance flavor.
• Choose foods with high water content, such as fruits, vegetables, or low-salt soups. For example, cucumbers, tomatoes, strawberries, and watermelon contain more than 90 percent water.
• Avoid alcohol and caffeinated drinks, which can lead to fluid loss.

Taking small sips during meals may help prevent you from feeling full too quickly. You may also find it helpful to drink most of your fluids between meals.

Ask About Medications To Improve Appetite

If you’ve lost your appetite due to kidney cancer or its treatment, talk to your healthcare provider about whether medications may help.

Your doctor may suggest certain prescription medications to help increase your appetite. Examples include:

• Metoclopramide
• Megestrol acetate
• Olanzapine
• Dexamethasone

Find Social Support

Loss of appetite can affect your quality of life. Consider reaching out to family or friends. Sharing meals with others may make eating feel more enjoyable and less stressful.

If you are caring for someone with kidney cancer, remember that you cannot control whether they eat. Pressuring them to eat may create stress or conflict and can make appetite loss worse.

Join the Conversation

On MyKidneyCancerTeam, people share their experiences with kidney cancer, get advice, and find support from others who understand.

How has kidney cancer or its treatment affected your appetite? Let others know in the comments below.