This guidebook can be downloaded and printed in a PDF format to help you figure out what to eat before and after surgery for stomach cancerNutrition in Stomach Cancer Guidebook (courtesy of the McGill University Health Centre)

Frequently Asked Questions – Nutrition

Will my weight change after surgery?

  • Most gastric cancer patients lose a significant amount of weight after surgery. The majority of weight loss occurs in the first 3 months following surgery.⁴
  • Weight loss is common for a few reasons:
    1. The tumor blocks off part of the GI tract, making it difficult for food to pass through.
    2. A decreased appetite may be a symptom of gastric cancer itself.
    3. After surgery, what is left of the stomach is much smaller. This means a smaller amount of food is able to fill it up. So, patients can  feel full, even though they might not have eaten enough food to give their body energy and maintain their weight.
    4. The feeling of early fullness can cause nausea and vomiting.⁵
    5. Dumping Syndrome – food moves through the stomach and small intestine very quickly. Nutrients are not absorbed and the patients can quickly lose weight.

What can I eat? How will this change around the time of my surgery?

  • Because gastric cancer affects major parts of your digestive system, you should expect your diet to change after your diagnosis and treatment.
  • A typical diet in the days following your surgery might look something like this:
    • Day 1: ice chips
    • Day 2-4: small sips of clear fluids (e.g.: water, tea, coffee)
    • Day 5-7: fluids (broth soups, nutritional supplement drinks, etc.)
    • Discharge from hospital: pureed diet (soups, mashed food, etc.)
    • When your doctor says so, you can begin following a soft food diet. This resource has a lot of helpful information about about what to eat following a gastrectomy.
  • There is no standard diet plan for all patients to follow after surgery. The guidelines above are very generalized. Each patient should follow the advice of their own doctor and nutritional support team.
  • It is easy to become deficient in certain key vitamins such as B12, and folate, as well as calcium and iron. Your body needs these ingredients to keep up many of its regular functions, so it could be a good idea to take vitamin supplements.  
  • It can take up to a year to adjust to a maintainable diet and appetite after treatment for gastric cancer.⁵

Tube feeding: What is it, and can it help?

  • If a patient cannot chew and swallow food (known as dysphagia), they may be fed enterally.
  • Enteral nutrition (often referred to as tube feeding) uses a flexible tube to deliver nutritionally-rich fluid directly to the GI tract while bypassing the mouth.
  • This is done to make sure patients are still absorbing enough calories, vitamins and nutrients even when they are unable to eat normally.
    • Nasoenteral nutrition – a feeding tube is passed through the nose to the esophagus and directly into the stomach. Nutritional fluid can be delivered to the stomach through the tube. This is typically only used immediately following surgery.
    • Enteral nutrition can be started within 6-12 hours after surgery.⁵
  • Another type of enteral nutrition uses a jejunostomy (an opening in the jejunum)
    • An incision is made in the skin of the abdomen. A feeding tube is passed through this incision and secured in place. Nutritional fluid can be passed directly into the small intestine for digestion and absorption (see Figure 1)
    • A jejunostomy feed tube might be referred to as a “J tube”
    • This is a longer-term solution to enteral nutrition after gastrectomy (compared to a nasoenteral tube).
    • One study looked at the pros and cons of using a jejunostomy feeding tube at home for six weeks after surgery.¹
      • They gave one group of patients a jejunostomy tube and overnight fluid feeding through an electronic pumping device. This means that every night while the patients slept, the device put a certain amount of nutritionally-supplemented fluid right into their jejunum.
      • This group of patients lost less weight overall than the control group, who was receiving standard care.
      • After evaluating these patients for six months after surgery, they also found that patients with the jejunostomy and overnight feeding had a better quality of life and were generally pleased with their treatment!¹
    • Using a feeding tube can be a viable way for cancer patients to maintain their nutrition and quality of life following surgery.

A gastrostomy may be done if parts of the stomach and duodenum are still left intact. This method is similar to the jejunostomy, but the feeding tube is placed into the stomach instead of the jejunum.⁵

Figure 1: Illustrates enteral nutrition given by a jejunostomy 

What is parenteral nutrition?

  • Enteral nutrition is used when patients cannot eat normally through the mouth, but their GI tract is not damaged.
  • Parenteral nutrition is used when patients cannot use enteral nutrition. This might be the case if the intestinal system is damaged and unable to absorb nutrients.⁵
  • Parenteral nutrition inserts a catheter tube into the patient’s vein, and delivers a nutrient-rich fluid into their bloodstream.
  • This is a more direct way of ensuring that nutrients are being absorbed into the blood than enteral nutrition is.⁵
  • However, parenteral nutrition is also associated with a higher chance of infection from inserting and maintaining the catheter.⁵ So, it is only recommended when patients are unable to tolerate oral or enteral nutrition.

What can be done before surgery?

  • Preoperative nutrition refers to what you’re eating and drinking before surgery.
  • Malnutrition (i.e.: being underweight or lacking important vitamins) in the time before surgery is associated with a higher risk of death or complications after surgery.⁵
  • Enteral nutrition (see above) given for some time before surgery may help to reduce inflammation and help with recovery after surgery.⁵
  • One specific type of preoperative nutrition is called Immunonutrition.
    • Immunonutrition supplements patients’ diets with ingredients which help to specifically boost the immune system.
    • Some studies have shown that immunonutrition before surgery can increase the number of working immune cells in our body. It may also minimize complications and the length of hospital stay after surgery.
  • It is also very important to make sure patients are receiving adequate nutrition right after their surgery:
    • Enteral nutrition can be given within 6-12 hours of surgery.
    • Maintaining nutrition right after surgery can help preserve the lining of the GI tract and significantly reduce the risk of infection.⁵
  • Anemia (low iron in the blood) and Vitamin B12 deficiency are some of the most common nutritional symptoms related to gastric cancer surgery.
    • Thus, it is recommended that patients begin taking iron and B12 supplements as soon as possible to minimize these symptoms in the long run.⁵

Nutrition in Advanced Gastric Cancer

  • Although advanced gastric cancer patients typically do not have surgery, they can still face challenges with eating:⁵
    • Narrowing of the GI tract (e.g.: esophagus, the top cardiac region of the stomach, the bottom pyloric region of the stomach) makes it difficult for food to pass through
    • Chemotherapy causes side effects such as nausea, vomiting, diarrhea or constipation.
    • Cancerous cells are impairing the absorption of nutrients and other GI functions.
  • All of these situations can lead to malnutrition and weight loss.
  • If oral (eating normally) or enteral nutrition are not helpful, patients may use home parenteral nutrition (see above) instead.
  • Chemotherapy patients with malnutrition have a higher chance of having severe complications from their treatment.²
  • This shows us that nutritional status can directly influence patient quality of life for all gastric cancer patients.²
  • So, it is extremely important to follow the recommended diet suggested by your physician!

What is the Elemental Diet?

  • An elemental diet is a supplement which provides nutrients in the simplest form possible. This means the GI tract has to do a lot less work to break down the food you eat. It makes digestion and absorption much easier!
  • The elemental diet often comes as a drink which is very high in calories and nutrients. It may be prescribed when a patient is unable to eat and absorb enough food to maintain their nutrition.
  • New research from Japan is showing the potential advantages of adding the elemental diet supplement to patients’ standard diet after a gastrectomy.3,6
    • This research was done to address the common problem of weight loss after surgery. The elemental diet gives extra calories in a way that is easy for patients to digest, so there is a smaller chance that their bodies are underfed.
    • Patients who combined their soft-food diet after surgery with an elemental diet drink lost less weight than patients who only at normal food.3,6
  • These results look promising, but more research is still needed before the elemental diet is used as standard treatment for patients after gastrectomy.

How can we test for malnutrition?

  • Patients who are suffering from malnutrition after their surgery may notice some of these common symptoms:
    • Diarrhea – may indicate an inability to absorb fat, or dumping syndrome
    • Nausea and vomiting – may indicate dumping syndrome or gastric stasis (which is when foodstuffs do not “move along” the GI tract like they are supposed to).
    • Feeling full early – may indicate gastric stasis.⁴
  • Many different tests can be done to find out what the problem is and how it can be fixed by altering your diet.
  • Gastric Emptying is the ability of the stomach to release foodstuffs to the small intestine.
    • Scintography: In this test, patients eat a standard meal (toast and eggs). The eggs contain a specially-labelled molecule. Doctors analyze samples of the air you breathe out to track this molecule. This tells them how long it takes for food to pass out of your stomach!⁴
    • If your stomach is not able to empty properly, you may feel full early or experience nausea and vomiting. This condition is called gastric stasis (“stasis” means “stopping”, so “gastric stasis” means the stomach has stopped moving!)
    • This can be treated with medication. The symptoms can also be lessened by eating smaller meals, and avoiding solid food.⁴
  • Dumping Syndrome: food passes too quickly from the stomach into the small intestine. Normally, food spends some time being broken into small pieces by the blender-like muscles of the stomach. When this process does not occur properly, much larger pieces of food enter the small intestine.
    • Oral Glucose Tolerance Test: In this test, patients who have fasted (not eaten) ahead of time consume a very sugary beverage. The doctor monitors their blood sugar level over time. The amount of sugar absorbed into the bloodstream over time indicates how fast the drink is passing through the GI tract.⁴
    • Dumping syndrome can be treated with medication. One example is a medication called “octreotide” which slows digestion.⁴
    • More research is needed to find out what the best diet to follow for dumping syndrome management is. Although, eating small amounts of liquid/pureed foods throughout the day is easier on the GI tract and may help with some symptoms.
  • Fat malabsorption: the body has a hard time breaking down fatty foods. This is quite common after gastric cancer surgery. It often shows up as increased fat in the fecal material.⁴
    • Diagnosing fat malabsorption involves collecting a stool (feces) sample, and testing the amount of fat it contains.  
    • This symptom can be treated by giving lipase. Lipase is an enzyme made by the pancreas which helps to break down fat.
    • Fat malabsorption makes it more important to monitor levels of vitamins A, D, E and K. These important vitamins are absorbed with fat, so someone with fat malabsorption problems could suffer from vitamin deficiencies. One way to treat this issue is to take vitamin supplements.⁴

Works cited

  1. Bowrey, D.J. et al. A randomised controlled trial of six weeks of home enteral nutrition versus standard care after oesophagectomy or total gastrectomy for cancer: report on a pilot and feasibility study. Trials (Springer Nature). 2015. 16:531. Available from: doi: 10.1186/s13063-015-1053-y.
  2. Gavazzi, C. et al. Importance of early nutritional screening in patients with gastric cancer. British Journal of Nutrition. 2011. 106:(1773-1778). Available from: doi:
  3. Hiroshi, I. et al. Effects of an oral elemental nutritional supplement on post-gastrectomy body weight loss in gastric cancer patients: a randomized controlled clinical trial. Annals of Surgical Oncology. 2016. 23:9(2928-2935). Available from: doi: .
  4. Rogers, Christie. Postgastrectomy nutrition. Nutrition in Clinical Practice. 2011. 26:2(126-136).  Available from: doi: 10.1177/0884533611400070.
  5. Rosania, R. et al. Nutrition in patients with gastric cancer: an update. Gastrointestinal Tumors. 2016. 2(178-187). Available from: doi: 10.1159/000445188.
  6. Yu, O. et al. Effectiveness of postoperative elemental diet (Elental©) in elderly patients after gastrectomy. World Journal of Surgical Oncology. 2016. 14;(268). Available from: doi: 10.1186/s12957-016-1013-3.