There’s no evidence that any one specific diet can treat lung cancer. However, eating healthy may help enhance your overall health, help improve energy levels, and give you more strength during your treatment.

It might be difficult to eat a well-balanced diet right now. Lung cancer and its treatments can reduce your appetite. Chemotherapy in particular might change the way food tastes, and make your mouth too sore to eat anything.

Work with your doctor and a dietitian to find a healthy eating plan that works for you. They’ll help you choose foods to keep up your weight and optimize your health during lung cancer treatment.

There’s no one “best diet” for people with lung cancer. Your ideal diet depends on your:

  • lung cancer treatment plan and any side effects you experience
  • preferences
  • weight
  • other conditions, such as diabetes or heart disease

The goals of any lung cancer diet are to:

  • provide you with enough calories to prevent weight loss
  • give you the essential nutrients your body needs, including vitamins, minerals, protein, healthy fats, and carbohydrates
  • help relieve treatment side effects like diarrhea, nausea, or constipation

Talk with your doctor and a dietitian who specializes in cancer. They can tailor a diet to your needs and food preferences.

The ketogenic, or keto, diet is a very low carb, high fat diet. Some research suggests that the keto diet may be effective for treating advanced cancers, including lung cancer.

However, studies have shown that the keto diet is difficult to follow for people who have lung cancer, especially when undergoing treatments like chemotherapy and radiation. It may lead to decreased calorie intake.

Research in this area is ongoing. It’s important to consult your doctor before making any dietary changes. Your medical team will work with you to decide the best diet for you based on your overall health and outlook.

Food is essential to good health. Whenever possible, it’s important to choose nourishing foods to help energize your body and keep you strong. This can help improve treatment outcomes and promote overall well-being.

Following a well-balanced diet rich in fruits and vegetables and other healthy foods may help reduce your risk of developing a number of chronic diseases, including cancer.

Whenever possible, try to choose foods that provide protein, healthy fats, vitamins, and minerals, and choose balanced meals and snacks that are rich in protein. Protein is very important for people with cancer as muscle loss is common, especially in people with advanced cancers.

However, what’s most important is making sure that you stay nourished and eat enough calories to keep yourself energized and prevent weight loss. If you’re struggling to consume enough calories, consult your medical team for advice.

Smoking is the main cause of lung cancer. It causes about 80 percent of lung cancer deaths. But there’s also evidence that diet plays some role in lung cancer risk, especially in smokers.

In a study published in the European Journal of Clinical Nutrition, people who ate a lot of whole grains and fruits were less likely to develop lung cancer than those whose diets were low in these healthy foods.

Replacing red meat and other foods high in saturated fat with unsaturated fat sources like olive oil, nuts, and avocados may also help lower lung cancer risk, especially in people who smoke.

Fruits and vegetables are an important addition to an anticancer diet, especially in smokers. Nutrients like beta carotene and vitamin A found in foods such as sweet potatoes, carrots, and cantaloupe may help reduce lung cancer risk.

Maintaining a healthy body weight and being physically active throughout life may prevent cancer.

Studies also suggest that having high levels of vitamin D in your blood may also protect against lung cancer.

Your body makes vitamin D from sunlight. Vitamin D is also added to certain fortified foods. However, vitamin D supplementation is necessary if you have low vitamin D levels.

Speak with your healthcare provider about getting a vitamin blood test to assess your levels.

Lung cancer treatments can affect:

  • your appetite
  • your ability to eat
  • how well your body absorbs nutrients from food

Both the cancer itself and treatments like chemotherapy can lead to weight loss. Healthy eating can help prevent you from losing too much weight and becoming malnourished.

Eating a well-balanced diet and keeping your body fueled can help keep you healthy during lung cancer treatment. It may help reduce the risk of treatment-related side effects like weight loss.

Good nutrition can provide you with more energy and strength, and may help improve your quality of life during treatment.

Chemotherapy drugs are strong medications that kill cancer cells throughout your body. Because these medications are so potent, they can cause side effects like:

  • nausea and vomiting
  • diarrhea
  • constipation
  • loss of appetite
  • changes in smell and taste
  • mouth sores

Eating certain foods and avoiding others may help reduce these chemo-related side effects.

Every person has different needs, so it’s important to work with your healthcare team to come up with a plan that works for you. Here are some general tips.

For nausea and vomiting:

  • Eat bland foods such as toast, crackers, and rice.
  • Have smaller, more frequent meals instead of large meals.
  • Eating cold or room temperature foods may help when you’re feeling sick.

For diarrhea:

  • Eat foods that contain salt, such as pretzels or broth, to replenish the sodium lost from diarrhea.
  • Drink at least 1 cup of water or sports drink after each loose bowel movement.
  • Eat bland foods like rice, bananas, and toast until the diarrhea gets better.
  • Avoid milk, high fat foods, greasy foods, and sweets, which may make diarrhea worse.
  • Limit high fiber foods such as whole grains and fresh fruits and vegetables, unless your doctor instructs otherwise.

For constipation:

  • To help you go, eat high fiber foods such as whole grain cereals and breads, fresh vegetables, fresh fruits with their seeds and skin, fruit juices, and dried fruits such as prunes and apricots.
  • Drink more fluids, including water and pasteurized fruit juices. Warm drinks like tea or coffee may help relieve constipation.
  • Limit foods that may make constipation worse, such as cheese and eggs.

For appetite loss:

  • Eat more frequent small meals and snacks throughout the day instead of three large meals.
  • Increase the amount of high calorie, high protein foods in your diet, like peanut butter, chicken, hard-boiled eggs, hummus, and nuts.
  • Drink a nutritional supplement like a protein shake.

For taste and smell changes:

  • If you can’t stand the smell of cooking, serve foods cold or at room temperature.
  • Mix 1 teaspoon salt and 1 teaspoon baking soda into 4 cups water and rinse your mouth with it before eating to help make foods taste better.
  • Use plastic forks, spoons, and knives instead of metal utensils.
  • Freeze fruits before you eat them.
  • Try new seasonings and marinades until you find flavors that appeal to you.

For mouth sores:

  • Ask your doctor if you can take medication before you eat to relieve mouth pain.
  • Eat soft foods such as oatmeal and applesauce.
  • Try frozen foods such as ice pops, frozen yogurt, or ice chips.
  • Avoid foods that are spicy or salty.
  • Don’t eat anything acidic, such as oranges, lemons, or tomatoes.

Other foods to avoid

In certain situations determined by your doctor, you may need to avoid or reduce your consumption of specific foods and beverages, including:

  • Alcohol. Beer, wine, and liquor could interact with the cancer drugs you take. There is also some limited evidence that drinking alcohol may increase the risk of recurrence and mortality for existing breast cancer.
  • Sugar-sweetened beverages. Consuming less added sugar can help you maintain a healthy weight.
  • Highly processed foods and refined grains. A 2018 prospective study found a 10 percent increase in breast cancer risk for people who eat ultra-processed foods.

Nutrition is an important part of lung cancer treatment. The cancer itself and its treatment side effects can reduce your appetite, making it harder for you to get the calories and nutrients you need right now.

If you’re not eating well and losing weight, talk with your doctor. A dietitian can help you fill in the gaps in your diet.

Adding more nutrient-dense and calorie-rich foods can help you keep up your strength and feel better during your treatment.