The Importance of Nutrition for Gastric Cancer

Written by: Julia Zakrzewski, RD

Updated: February 3rd, 2026

There are several types of Gastrointestinal (GI) cancers, including: esophageal, gastric (stomach), colorectal, pancreatic, liver, small intestine, and biliary tract cancers.

A GI cancer may affect your nutritional intake and increase the risk of malnutrition. If you’ve recently been diagnosed, taking proactive steps to optimize your diet may benefit your cancer journey and post-operative recovery.

Read on to learn all about the benefits of adopting good nutrition practices after a GI cancer diagnosis!

Why Nutrition Matters in GI Cancers

Nourishing your body well is an important part of living with GI cancer. Getting enough daily calories, nutrients, vitamins, and fluids helps your body stay energized, better tolerate chemotherapy, and maintain quality of life throughout treatments.

To stay on top of your nutrition and overall recovery, your healthcare team will help you develop an eating plan to stay nourished and energized while managing a cancer diagnosis.

Some nutrition goals your specialists may prioritize include:

Maintaining strength
Prevent significant weight loss (cachexia)
Supporting your overall health and immune function
Managing your symptoms

Gastric Cancer and Nutritional Challenges

Tumours and gastric cancer treatments may contribute to nutritional challenges, and they should be addressed as early as possible to aid with recovery.

Tumours

Some nutrition challenges may be linked to the cancer itself, like a tumour blocking a portion of the digestive tract. This may cause discomfort and make it harder to eat enough at meals.

Some people with gastric cancer may also experience delayed stomach emptying, which can cause them to feel full longer. This may affect how often they want to eat throughout the day, potentially making it harder to get enough nutrition.

Eating smaller portions more frequently throughout the day may help you meet your intake goals.

Treatments

Certain treatments for gastric cancer (like chemotherapy or a gastrectomy) may cause side effects that contribute to nutritional challenges, such as:

Impaired nutrient absorption (notably iron, vitamin B12, folate, and calcium)
Nausea
Vomiting
Diarrhea
Constipation
Mouth sores
Dumping syndrome (specific to a gastrectomy)

It’s common to feel more tired while going through treatment. Talking with a specialist can help you find ways to ease these side effects and make mealtimes more comfortable.

Consider Working with a Registered Dietitian

A registered dietitian is a licensed healthcare provider specializing in the nutritional management of illnesses. Their knowledge and counseling services can be profoundly helpful when you’re navigating a cancer diagnosis.

Specifically, a dietitian may help you:

Manage symptoms that affect your nutritional intake
Stay hydrated
Follow evidence-based nutrition guidelines for cancer
Build meals with adequate protein
Control weight changes and prevent weight loss
Recognize signs and symptoms that warrant a visit to the hospital
Decrease your risk of cancer recurrence

Your healthcare team can help connect you with a dietitian, either right at your cancer center or through an outpatient referral.

If you have health benefits, you may have coverage for a registered dietitian; however, it’s best to consult your insurance provider to understand your specific coverage options.

If you don’t have insurance, you may ask to be referred to a dietitian who follows a “sliding scale” payment option, which may be more affordable.

Dietary Guidelines for Those Living with Gastric Cancer

Eating well can feel challenging during treatment, but nourishing your body is an important part of your care. Making small, manageable changes to your diet can help you maintain strength and energy. Here are some general dietary guidelines that may help you stay nourished while managing gastric cancer:

Have small, frequent meals more often to help meet your daily nutrition goals
Eat nutrient-rich foods first, such as enriched smoothies or meal replacement shakes
Limit your intake of high-fibre foods because they can rapidly make you feel full
Save your water, tea, or other drinks for last to avoid filling up too quickly
Try to limit your intake of carbonated beverages and choose flat options instead

Preventing weight loss is a pillar of GI cancer care because muscle and fat loss can make it more challenging for your body to tolerate cancer treatments and stay healthy overall.

If your weight changes, your healthcare team may adjust your health plan and start incorporating higher-calorie foods into your diet (such as full-fat dairy compared to skim milk products) more often.

If you see your weight going down, let your healthcare team know right away so they can support you.

Managing Nausea and Other Symptoms

If you’re experiencing GI symptoms, such as nausea while eating, try making these small changes.

Less Smelly Foods

Consider having neutral-smelling foods with low fragrance levels to minimize nausea before eating. Examples of these foods include plain pasta, rice, cooked potatoes, toast, and bananas, among others.

Try Cold Options

Try eating cold, easy-to-digest foods like yogurt or popsicles, as they may be better tolerated than hot, high-fat meals. They may also smell less intensely.

Take Your Time

During your meal, try to relax and take your time chewing and swallowing your food. Reducing anxiety during meals may help alleviate nausea and make you feel more at ease.

Seek Medical Support

Consider reaching out to your healthcare provider if you’re experiencing persistent diarrhea, vomiting, and nausea. They may recommend medications to ease these symptoms and help you get back on track.

Nutritional Support at Different Stages of the Cancer Journey

Here are some generalized nutrition goals you may encounter at various stages of the cancer journey.

Pre-treatment

Before your GI cancer treatment, consider making changes at home to optimize your nutrition and maintain your weight.

Try eating regular, nutrient-dense meals throughout the day that include vegetables, fruits, lean proteins, and nourishing fats (as tolerated).

If you’re unable to cook for yourself, ask family members or friends to help with meal preparation. Your healthcare team may also recommend a meal delivery service.

During-treatment

Some people may feel well enough to continue eating their regular diet while receiving treatment and won’t need to make any changes, particularly if their weight remains stable.

However, others may experience treatment side effects like weight loss, nausea, diarrhea, mouth sores, etc. Foods can also taste different, and your mouth might feel drier.

If this sounds like you, try eating smaller, nutrient-dense meals more frequently throughout the day and consider consulting your healthcare provider for additional support.

Post-treatment

After you’ve completed treatment, your nutrition goals may shift to prioritize healing and decreasing the risk of cancer recurrence.

You can achieve this by eating a balanced diet of fruits, vegetables, lean protein, fibrous grains, and plant-based proteins (lentils, beans, etc.). Also, consider limiting your alcohol intake and continuing to take supplements as directed by your health care team.

If you’ve had surgery and now live with an altered digestive tract, your healthcare team will need to debrief you on nutritional best practices, including meal portion sizes.

Palliative care

If you and your oncology team opt to proceed to palliative care, you may shift your goals towards comfort and quality of life through food. You’ll need to work with your healthcare team to manage your nutrition at this stage.

Enteral Nutrition Isn’t Necessary for Everyone

Oral nutrition refers to the consumption of nutrients through eating or drinking by mouth. Sometimes, people are unable to consume enough orally to stay healthy. In these cases, a physician may recommend enteral nutrition.

Enteral feeding can enhance nutritional intake by directly administering nourishment into the gastrointestinal tract. There are various types of enteral feeding tubes available for both short-term (nasogastric tube) and long-term (PEG tube) applications.

If enteral nutrition is required, you and your physician will review the options for tube feeding. If you receive a long-term enteral tube, your surgeon’s team will teach you how to manage your diet and lifestyle moving forward.

Enteral nutrition isn’t mandatory for managing gastric cancer, and will only be suggested at a specialist’s discretion.

The Role of the Healthcare Team

Your healthcare team may include your family doctor, oncologist, other specialists, nurses, and allied health professionals, such as registered dietitians and social workers.

They will support you and offer evidence-based treatment options to help you recover.

Making the Most of your Appointments

You might feel more prepared for your medical appointments by having a plan. Here are some quick tips to help you make the most of your visit:

Write down your questions before your visit
Track how often you’re experiencing symptoms (for example, you experienced nausea 5/7 days last week)
Consider bringing a family member or friend for an extra set of ears
Document answers in a notebook or ask the provider if you can record the conversation

Conclusion

Key nutrition concerns associated with gastric cancer may include maintaining a healthy weight during treatment, minimizing the risk of malnutrition, and preventing nutrient deficiencies.

In addition to supporting your recovery, good nutritional intake can help you feel well physically and may help you better manage possible side effects from cancer drugs and treatments.

If you need help with your diet, your oncologist can connect you with a registered dietitian who understands cancer nutrition.