Nutritional therapy category a	Recommendations
Nutritional risk screening and malnutrition assessment b	Nutritional risk screening and malnutrition assessment should be completed within 24 and 48 hours after admission, respectively; NRS guide: NRS‐2002; Malnutrition assessment guide: PG‐SGA;
Early perioperative patients c	Patients with severe or moderate malnutrition should be given nutritional therapy for 7‐14 days before surgery; The route for nutrition can be ONS or EN. When EN cannot provide sufficient energy and protein or is not feasible, the PN route can be considered; Nutrition intake should be reverted to oral, ONS, or EN route soon after surgery (within 24‐48 hours), and for suitable patients, ERAS treatment can be implemented; Consider referring to the “CSCO guidelines for nutritional therapy of patients with malignant tumors” and “Chinese expert consensus on perioperative nutritional therapy of gastric cancer (2019 Edition)” for further details;
Late‐stage patients d , e	Nutritional risk screening and malnutrition assessment for non‐end‐stage patients should be regularly performed, and nutritional treatment plans should be formulated. Nutrition treatment should follow the five‐step principle; For end‐stage patients, the main goal of nutritional therapy is to reduce symptoms and maintain body weight, and individualized nutrition plans should be formulated for them. For additional details, refer to the “CSCO guidelines for nutritional therapy for patients with malignant tumor”;
Patients at home f	To provide nutritional and family rehabilitation guidance. Regular outpatient nutrition consultation at least once every 3 months is recommended.

Abbreviations: NRS, nutrition risk screening; PG‐SGA, patient‐generated subjective global assessment; ONS, oral nutritional supplements; EN, enteral; PN, parenteral; ERAS, enhanced recovery after surgery; CSCO, Chinese Society of Clinical Oncology.

Notes:

^a Malnutrition is common in patients with gastric cancer. Studies have shown that the rate of moderate to severe malnutrition in hospitalized patients with gastric cancer in China was 80.4%, seriously affecting the quality of life of the patients [265]. Recently, a phase III clinical study in China showed that for patients with metastatic gastric cancer, the combination of early nutritional therapy and physiotherapy on the basis of standard chemotherapy could significantly prolong survival [264]. Therefore, nutritional therapy should be an important part of anti‐tumor therapy for gastric cancer. Every gastric cancer patient should undergo timely and accurate nutritional risk screening, early nutritional guidance, and MDT consultation on the whole process of disease management.

^b Nutritional Risk Screening 2002 (NRS‐2002) is recommended for nutritional risk screening. Those with NRS‐2002 score ≥3 are at risk for malnutrition and need further assessment [266, 267, 268]. Patient‐generated subjective global assessment (PG‐SGA) is recommended for nutritional assessment. The PG‐SGA is a specific nutritional assessment tool for quick identification of cancer patients with malnutrition [266, 269]. According to the score, patients are divided into no malnutrition (score, 0‐1), suspected malnutrition (score, 2‐3), moderate malnutrition (score, 4‐8), and severe malnutrition (score, ≥9).

^c Perioperative nutritional therapy is an important aspect of enhanced recovery after surgery (ERAS). For eligible gastric cancer patients, nutritional therapy is recommended according to the ERAS principles and procedures [267, 270]. Some studies suggested that the immune‐enhanced enteral preparation could be beneficial to maintain lean body weight, reduce postoperative complications and infections and shorten the length of hospital stay, but more clinical evidence is still needed prior to clinical recommendation [267].

^d Nutritional intervention follows a five‐tier principle. Initially, nutritional education is chosen, followed by progressing upward to select oral nutritional supplements (ONS), total enteral nutrition (TEN), partial enteral nutrition combined with partial parenteral nutrition (PEN+PPN), and total parenteral nutrition (TPN), if the next tier cannot meet 60% of the target energy requirements for 3‐5 days, the previous tier should be selected [271].

^e Nutritional problems in late‐stage gastric cancer patients may include digestive tract obstruction, hemorrhage, gastroparesis, and more. Enteral nutrition is often not enough, and parenteral nutrition should be provided as per the patient's needs. Nutritional routes, such as nasogastric tube, nasointestinal tube and percutaneous gastrostomy, should be available to support the patient's nutritional requirements. If the symptoms of obstruction and bleeding can be improved with appropriate treatment, it is advisable to cautiously attempt to transition to EN under the premise of safety, and then to conduct comprehensive treatment in MDT discussion. In the whole process of gastric cancer management, attention should be paid to actively prevent and treat cachexia. Active prevention, accurate evaluation, early diagnosis and timely treatment should be offered because once the patient enters the cachexia stage, it is difficult to reverse.

^f For patients with gastric cancer at home, it is suggested that proper nutritional and rehabilitation guidance should be offered to the caregiver. Regular nutrition consultation at least once every 3 months is recommended. ONS should be encouraged, and body weight assessment should be performed every 2 weeks [271].