Cancer Nutrition: Diet Tips During Treatment

How Should I Eat During Cancer Treatment?

During cancer treatment, focus on eating a balanced diet rich in protein, fruits, vegetables, and whole grains. If you have difficulty eating, prioritize getting enough calories and protein through whatever foods you can tolerate. The most important goal is getting adequate nutrition to support your body through treatment and recovery.

The same general principles of healthy eating apply whether you have cancer or not: eat a variety of nutritious foods, maintain a healthy weight, avoid excessive processed foods, and stay physically active. However, cancer treatment can make following these guidelines challenging, and you may need to adapt your eating patterns to your current circumstances.

Cancer and its treatments can affect your appetite, ability to eat, and how your body processes nutrients in many ways. Some people experience no eating problems at all, while others face significant challenges that vary throughout treatment. Understanding that your nutritional needs are individual and may change over time is the first step toward managing your diet effectively.

The primary goals of nutrition during cancer treatment are to maintain adequate energy levels, preserve muscle mass, support your immune system, and help your body tolerate and recover from treatments. Achieving these goals requires flexibility and sometimes means prioritizing calories and protein over typical healthy eating guidelines when appetite is poor.

Why Protein Matters During Cancer Treatment

Protein is particularly important during cancer treatment because your body uses it to repair tissues, maintain muscle mass, support immune function, and produce enzymes and hormones needed for recovery. Cancer treatments like surgery, chemotherapy, and radiation all increase your body's protein requirements.

Most cancer patients need approximately 1.2 to 1.5 grams of protein per kilogram of body weight daily, which is higher than the standard recommendation for healthy adults. For a person weighing 70 kg (154 lbs), this translates to 84-105 grams of protein per day. Meeting these requirements can be challenging when appetite is poor, so choosing protein-rich foods at every meal and snack becomes essential.

Excellent sources of protein include fish, poultry, eggs, dairy products (milk, cheese, yogurt), legumes (beans, lentils), nuts, and soy products. If you're having trouble eating enough protein from food, your healthcare team may recommend protein supplements or high-protein medical nutrition drinks.

• Fish and seafood: 20-25g protein per 100g, easily digestible
• Chicken and turkey: 25-30g protein per 100g, versatile in cooking
• Eggs: 6g protein per egg, can be prepared many ways
• Greek yogurt: 10g protein per 100g, good for snacks
• Cottage cheese: 11g protein per 100g, mild flavor
• Beans and lentils: 7-9g protein per 100g cooked, high fiber
• Nuts: 15-25g protein per 100g, calorie-dense

When Standard Nutrition Advice Doesn't Work

Treatment side effects may make it difficult or impossible to follow standard nutrition recommendations. During these periods, the priority shifts to simply getting enough calories and nutrients by any means possible. Eating what you can tolerate, even if it's not your usual healthy diet, is far better than not eating at all.

It's important to understand that short-term deviations from optimal nutrition during difficult treatment periods will not significantly impact your long-term health. Your body's immediate need for energy to cope with treatment takes precedence over long-term dietary ideals. Work with your healthcare team to find solutions that help you maintain adequate nutrition during challenging periods.

How Can I Maintain a Stable Weight?

Weight changes are common during cancer treatment - some patients lose weight while others gain. The goal is to keep your weight as stable as possible because significant weight changes make it harder to tolerate treatment and recover. Weigh yourself weekly and report changes of more than 5% to your healthcare team immediately.

Maintaining stable body weight during cancer treatment is associated with better treatment outcomes, fewer complications, improved quality of life, and faster recovery. Both unintentional weight loss and excessive weight gain can negatively impact your health and treatment effectiveness.

Weight loss during cancer can occur for multiple reasons. The cancer itself may increase your metabolism, treatments can cause nausea, vomiting, taste changes, or difficulty swallowing, and psychological factors like anxiety or depression may reduce appetite. Additionally, some cancers produce substances that interfere with normal appetite regulation and metabolism.

Weight gain can also occur during treatment, particularly with certain hormone therapies for breast or prostate cancer, corticosteroid medications often given with chemotherapy, reduced physical activity due to fatigue, or emotional eating in response to stress. Understanding the cause of weight changes helps in developing appropriate strategies to address them.

Monitoring Your Weight

Weighing yourself regularly - ideally once a week at the same time of day - allows you to detect changes early. Record your weight and share this information with your healthcare team at each appointment. Small fluctuations of 1-2 kg are normal, but consistent trends upward or downward warrant attention.

If you notice you're losing weight unintentionally, don't wait to address it. Early intervention is much more effective than trying to reverse significant weight loss later. Similarly, if you're gaining weight and want to limit it, small adjustments to diet and activity are easier to implement than trying to lose substantial weight during treatment.

What Should I Do If I Have Increased Appetite?

Some cancer treatments, particularly corticosteroids and certain hormone therapies, can increase appetite and lead to weight gain. Managing increased appetite involves choosing filling, nutritious foods, eating regular meals to prevent extreme hunger, staying hydrated, and maintaining physical activity within your abilities.

Weight gain during cancer treatment can feel frustrating, especially if you're working hard to stay healthy. However, it's important not to attempt strict dieting or significant calorie restriction during active treatment. Your body needs adequate nutrition to fight the disease and recover from treatment. Instead, focus on making healthier choices while still meeting your nutritional needs.

Corticosteroids like dexamethasone and prednisone, commonly given with chemotherapy to reduce side effects, can significantly increase appetite and cause fluid retention. These medications can create a sensation of never feeling full, making it challenging to control food intake. Understanding that this is a medication side effect, not a lack of willpower, can help reduce frustration.

Hormone treatments for breast cancer (like tamoxifen or aromatase inhibitors) and prostate cancer (hormone therapy) can also lead to weight gain through changes in metabolism and body composition. Additionally, reduced physical activity due to treatment-related fatigue contributes to weight gain in many patients.

Strategies for Managing Increased Appetite

Eating regular, balanced meals helps prevent extreme hunger that can lead to overeating. Include protein and fiber at each meal to promote satiety. The "plate method" can be helpful: fill half your plate with vegetables, a quarter with lean protein, and a quarter with whole grains or starchy foods.

Choose snacks wisely. Instead of calorie-dense processed snacks, opt for fresh fruit, vegetables with hummus, yogurt with berries, or a small handful of nuts. Keep healthy snacks readily available so you have good options when hunger strikes.

• Eat three balanced meals daily with planned, healthy snacks between meals
• Choose high-fiber foods like whole grains, vegetables, and legumes that promote fullness
• Drink water before and with meals - sometimes thirst is mistaken for hunger
• Avoid sugary drinks and excessive sweets which add calories without nutrition
• Eat slowly and mindfully - it takes 20 minutes for your brain to register fullness
• Keep a food diary to become more aware of eating patterns
• Stay physically active as much as your energy allows

What Can I Do When I've Lost My Appetite?

Loss of appetite is one of the most common nutrition challenges during cancer treatment. When you don't feel like eating, focus on eating small amounts frequently, choosing calorie-dense foods to maximize nutrition in small portions, and eating whenever you feel able rather than at set mealtimes. Even small amounts of food help maintain your strength.

Appetite loss during cancer treatment can result from the cancer itself, treatment side effects like nausea or taste changes, pain, fatigue, depression, or medications. Whatever the cause, inadequate food intake leads to weight loss, muscle wasting, fatigue, and reduced ability to tolerate treatment. Addressing appetite loss proactively is essential.

Understanding that appetite varies from day to day and even meal to meal can help reduce pressure around eating. On days when you feel better, try to eat more. On difficult days, focus on staying hydrated and eating whatever you can manage. Small victories matter - every bite of food provides your body with resources for healing.

The emotional aspects of appetite loss deserve attention too. Food often plays a central role in family and social life, and not being able to eat normally can feel isolating. Communicate with family members about how they can best support you - sometimes this means not pressuring you to eat, and other times it means preparing favorite foods or eating together in a relaxed setting.

Practical Tips for Eating When You're Not Hungry

When appetite is poor, standard meal patterns may not work. Instead of three large meals, aim for 5-6 smaller meals or snacks every 2-3 hours. Having food available and ready to eat removes barriers - keep easy snacks within reach and prepare foods in advance when you have more energy.

Maximize nutrition in each bite by choosing calorie-dense and protein-rich foods. This is not the time to fill up on low-calorie vegetables or diet foods. Instead, focus on foods that provide significant nutrition in small portions.

• Eat your favorite foods: If something appeals to you, eat it regardless of whether it's "healthy"
• Try small portions: A full plate can be overwhelming; start with tiny amounts
• Eat at unexpected times: If you're hungry at midnight, eat then
• Make food visible: Leave snacks where you'll see them as reminders to eat
• Try soft, easy-to-eat foods: Yogurt, smoothies, soup, eggs, pasta require less effort
• Avoid strong food smells: Cold foods often smell less than hot foods
• Create pleasant eating environments: Eat with company, use nice dishes, or eat while watching TV

High-Calorie Foods for Small Appetites

When you can only eat small amounts, choose foods that pack maximum calories and nutrients into each bite. Adding extra fats and proteins to foods can significantly increase their nutritional value without increasing portion size.

Nutritional Supplement Drinks

Oral nutritional supplements (ONS) are specially formulated drinks that provide concentrated calories, protein, vitamins, and minerals. They come in various flavors and forms (ready-to-drink, powder to mix with milk or water) and can be valuable when food intake is insufficient.

Your healthcare team can prescribe medical nutrition drinks and advise on the best options for your needs. These supplements should complement, not replace, regular food whenever possible. Some people find them easier to consume chilled or over ice, and they can be incorporated into smoothies for variety.

How Can I Manage Nausea While Eating?

Treatment-related nausea can severely impact eating. Managing nausea involves eating small, frequent meals, choosing bland and cold foods, avoiding strong odors, eating slowly, resting after meals, and taking prescribed anti-nausea medications. Many patients find that certain foods trigger nausea while others are well-tolerated.

Nausea is one of the most challenging side effects affecting nutrition during cancer treatment. Modern anti-nausea medications have greatly improved nausea control for most patients, but many still experience some degree of nausea that interferes with eating. Working closely with your healthcare team to optimize anti-nausea medication is the first step in managing this symptom.

Understanding your nausea patterns can help you plan eating around better periods. Some people feel worse in the morning, others in the evening. Some experience nausea immediately after treatment, while for others it's delayed. Keep track of when you feel better and plan to eat during those times.

Food odors are a common nausea trigger. Hot foods tend to smell more than cold foods, so many people with nausea tolerate cold meals better. Having someone else prepare food, or preparing meals when you feel better and refrigerating them for later, can reduce exposure to cooking smells.

Foods That May Help With Nausea

Certain foods are generally better tolerated during periods of nausea. These tend to be bland, low-fat, low-fiber, and not strongly flavored. Individual tolerance varies greatly, so experiment to find what works for you.

• Dry, starchy foods: Crackers, toast, dry cereal, pretzels
• Bland grains: Plain rice, pasta, bread
• Clear broths and soups: Chicken or vegetable broth
• Cold foods: Yogurt, cottage cheese, cold sandwiches, smoothies
• Ginger: Ginger tea, ginger ale, ginger candies (evidence-supported)
• Citrus: Lemon water, citrus-flavored foods (for some people)
• Salty snacks: Pretzels, crackers, saltines (may help with queasiness)

Eating Strategies for Nausea

Small, frequent meals are almost universally recommended for managing nausea. An empty stomach can make nausea worse, but eating too much at once can also trigger problems. Aim to eat something every 2-3 hours, even if it's just a few crackers.

If you experience morning nausea, try eating a small dry snack before getting out of bed. Keep crackers or dry cereal on your nightstand. Eating slowly and chewing thoroughly helps digestion and may reduce nausea. After eating, rest in an upright or slightly reclined position rather than lying flat.

What Should I Eat If I Have Diarrhea?

Treatment-related diarrhea requires dietary adjustments to prevent dehydration and nutrient loss. Key strategies include staying well-hydrated with electrolyte-containing fluids, eating small frequent meals of easily digestible foods, avoiding high-fiber and fatty foods, and potentially trying lactose-free dairy products. Seek medical attention for severe or persistent diarrhea.

Diarrhea during cancer treatment can result from chemotherapy, radiation to the abdomen or pelvis, infections, medications, or surgical changes to the digestive system. It can lead to dehydration, electrolyte imbalances, and malnutrition if not properly managed. Your healthcare team may prescribe anti-diarrheal medications, but dietary management is also important.

Hydration is the top priority when you have diarrhea. You lose significant amounts of water and electrolytes with each episode, and these need to be replaced. Aim to drink at least 1.5-2 liters of fluids daily, more if diarrhea is severe. Include some drinks containing electrolytes (sodium, potassium) such as sports drinks, broths, or oral rehydration solutions available at pharmacies.

The timing and amount of fluid intake matters. Drinking large amounts at once can sometimes worsen diarrhea. Instead, sip small amounts of fluids frequently throughout the day. Avoid very cold drinks and drinks high in sugar, as these can worsen diarrhea in some people.

Foods to Choose and Avoid With Diarrhea

During episodes of diarrhea, choose foods that are gentle on the digestive system and help firm stools. As diarrhea improves, gradually reintroduce a wider variety of foods.

Lactose and Diarrhea

Prolonged diarrhea can temporarily damage the cells in your intestine that produce lactase, the enzyme needed to digest lactose (milk sugar). This can cause lactose intolerance even in people who normally tolerate dairy. If dairy products seem to worsen your diarrhea, try lactose-free alternatives. This intolerance usually resolves once diarrhea improves.

How Can I Relieve Constipation?

Constipation during cancer treatment is common and often caused by pain medications (especially opioids), anti-nausea medications, reduced activity, and inadequate fluid intake. Management includes drinking adequate fluids, eating fiber-rich foods when tolerated, staying physically active, and using prescribed laxatives. Prevention is easier than treatment.

Constipation is frequently experienced during cancer treatment and can cause significant discomfort. Pain medications, particularly opioids, are a major cause, but anti-nausea drugs, reduced physical activity, and decreased food and fluid intake also contribute. If you're taking opioid pain medications, your healthcare team should prescribe a stool softener or laxative to prevent constipation.

The relationship between fiber and constipation in cancer patients is complex. While fiber generally helps prevent constipation, if you have reduced bowel motility due to medications or other causes, increasing fiber without adequate fluids can actually worsen constipation. Work with your healthcare team to determine the right approach for your situation.

Adequate fluid intake is essential for preventing and treating constipation. Aim for at least 1.5-2 liters of fluids daily. Warm liquids like tea, coffee (in moderation), or warm water with lemon can stimulate bowel movements. Prune juice is a traditional remedy that works for many people due to its natural laxative compounds.

Tips for Managing Constipation

• Drink plenty of fluids - at least 8 glasses (2 liters) per day
• Include fiber-rich foods if tolerated: whole grains, fruits, vegetables, beans
• Try prune juice or stewed prunes - natural laxative effect
• Stay physically active as much as possible - even gentle walking helps
• Establish a routine - try to have a bowel movement at the same time daily
• Don't ignore the urge - go when you feel the need
• Take prescribed laxatives regularly if recommended by your healthcare team

What Can I Eat With Mouth or Throat Problems?

Mouth sores, dry mouth, difficulty swallowing, and taste changes are common during cancer treatment, especially with chemotherapy and head/neck radiation. Managing these symptoms involves choosing soft, moist, bland foods, avoiding irritants like acidic or spicy foods, maintaining good oral hygiene, and using prescribed treatments for pain and dryness.

The mouth and throat are particularly vulnerable to cancer treatment effects. Chemotherapy can cause mucositis (inflammation and sores in the mouth), while radiation to the head and neck area can cause severe mouth and throat problems including pain, dryness, difficulty swallowing, and taste changes. These issues can significantly impact nutrition and quality of life.

Taste changes are extremely common during cancer treatment. Foods may taste metallic, too salty, too sweet, or have no taste at all. These changes usually improve after treatment ends, but they can persist for weeks to months. Experimenting with different flavors, seasonings, and temperatures can help you find foods that are palatable.

Dry mouth (xerostomia) occurs when saliva production is reduced, often due to radiation therapy or certain medications. Saliva is essential for comfortable eating, swallowing, and protecting teeth from decay. Managing dry mouth involves frequent sips of water, using artificial saliva products, and choosing moist foods.

Foods and Strategies for Mouth Problems

• Choose soft, moist foods: Smoothies, yogurt, soft scrambled eggs, mashed potatoes, soups, pudding
• Add sauces and gravies: Make foods easier to swallow and more palatable
• Avoid irritating foods: Citrus, tomatoes, spicy foods, crunchy foods, alcohol
• Try room temperature or cool foods: Avoid very hot foods that can burn sensitive tissues
• Use straws for liquids if it makes drinking easier
• Rinse your mouth before eating to freshen your palate
• Experiment with flavors: Strong flavors may be more detectable with taste changes

Managing Taste Changes

If foods taste metallic, try using plastic utensils instead of metal, marinading meats in sweet or acidic sauces before cooking, or adding lemon or citrus flavors to foods. If foods taste bland, experiment with stronger seasonings, herbs, and spices. Cold foods typically have less taste than warm foods, which can be good or bad depending on the nature of your taste changes.

Some patients find that rinsing the mouth with water, tea, or baking soda solution before meals improves taste perception. Good oral hygiene, including brushing teeth and using mouth rinses, can help reduce bad tastes and improve food enjoyment.

When Should I Use Nutritional Supplements?

Oral nutritional supplements may be recommended when you cannot meet your nutritional needs through food alone. These products provide concentrated calories, protein, and essential nutrients. Always consult your healthcare team before using supplements, as some may interfere with cancer treatment. Vitamin and mineral supplements should not replace a balanced diet when eating is possible.

Medical nutrition supplements (also called oral nutritional supplements or ONS) are specially formulated products designed to provide complete or supplementary nutrition. They come as ready-to-drink shakes, powders, or puddings and typically provide 200-400 calories and 10-20 grams of protein per serving along with vitamins and minerals.

Your healthcare team may recommend nutritional supplements if you are losing weight despite your best efforts to eat, cannot eat enough food to meet your nutritional needs, have specific nutritional deficiencies, or need nutritional support before or after surgery. A registered dietitian can help determine which products are most appropriate and how to incorporate them into your diet.

Regarding vitamin and mineral supplements, most oncologists recommend getting nutrients from food whenever possible. High-dose antioxidant supplements (vitamins A, C, E, selenium) may interfere with some cancer treatments that work by creating oxidative stress in cancer cells. Always discuss any supplements with your healthcare team before taking them.

What If I Cannot Eat Normally?

When eating by mouth is not possible or sufficient, nutrition can be provided through a feeding tube (enteral nutrition) or directly into the bloodstream (parenteral nutrition). These medical nutritional support methods ensure adequate nutrition when the normal eating route is compromised. They may be temporary or long-term depending on your situation.

Sometimes cancer or its treatment makes it impossible to eat enough by mouth. This can occur with cancers affecting the mouth, throat, or digestive system, severe side effects preventing eating, or preparation for certain surgeries. In these situations, alternative nutrition support can maintain your nutritional status.

Enteral nutrition (tube feeding) delivers liquid nutrition directly into the stomach or small intestine through a tube. The tube may be passed through the nose (nasogastric tube) for short-term use or placed directly through the abdominal wall into the stomach or intestine (PEG or PEJ tube) for longer-term use. Tube feeding uses the digestive system, which helps maintain gut health.

Parenteral nutrition provides nutrients directly into the bloodstream through an intravenous line, bypassing the digestive system entirely. It's used when the digestive tract cannot be used or needs to rest. Parenteral nutrition requires careful management and monitoring by healthcare professionals.

Many patients can manage their tube feeding or parenteral nutrition at home with support from specialized nurses and dietitians. The choice of nutritional support method depends on your specific situation, expected duration, and what your body can handle.

What About Nutrition for Children With Cancer?

Children with cancer face similar nutritional challenges as adults but have unique needs for growth and development. The priority is maintaining adequate nutrition and positive associations with food. Avoid pressuring children to eat, maintain normal family mealtimes when possible, offer a variety of foods, and work closely with pediatric oncology dietitians.

Children undergoing cancer treatment may experience the same eating difficulties as adults - nausea, appetite loss, taste changes, and mouth sores. However, children have additional nutritional needs to support their growth and development, making adequate nutrition even more critical.

The psychological aspects of eating are particularly important for children. Mealtimes can become stressful if there's too much focus on eating or if children feel pressured. The goal is to help children maintain as positive a relationship with food as possible, even during difficult treatment periods. This foundation will serve them well after treatment ends.

Maintain normal family routines around meals as much as possible. Eat together, make mealtimes pleasant, and avoid making food a battleground. Offer choices within what's available, use child-size portions that don't overwhelm, and avoid using food as reward or punishment. If a child refuses a meal, don't force it - try again later.

• Keep mealtimes low-pressure - don't force eating or comment excessively on how much is eaten
• Offer small, frequent meals and snacks throughout the day
• Let children help choose what foods to try
• Serve foods in appealing ways - presentation matters to children
• Be flexible with food preferences, which may change frequently
• Maintain normal family mealtimes even if the child eats something different
• Encourage physical activity to stimulate appetite when energy allows

Where Can I Get More Help and Support?

Many cancer centers have dietitians specializing in oncology nutrition who can provide personalized advice, meal planning, and supplement recommendations. Ask your healthcare team for a referral. Support groups, cancer organizations, and online resources can also provide practical tips and emotional support from others who understand nutritional challenges during cancer treatment.

If you're struggling with nutrition during cancer treatment, speak with your oncologist, nurse, or other healthcare team members. Most cancer centers have registered dietitians who specialize in oncology nutrition and can provide individualized assessment and recommendations tailored to your specific situation, treatment, and preferences.

A dietitian consultation can help you assess your current nutritional status, identify and address nutritional problems, develop practical meal plans, recommend appropriate supplements, access nutrition support services if needed, and manage treatment side effects affecting eating. In many healthcare systems, dietitian services for cancer patients are covered by insurance or provided at no additional cost.

Beyond professional help, connecting with other cancer patients can provide valuable practical tips and emotional support. Cancer support groups, patient advocacy organizations, and online communities offer opportunities to learn from others' experiences with nutrition challenges. However, remember that everyone's situation is different - what works for one person may not work for another.