Nutritional risk and malnutrition is common in cancer patients, which is one of the significant factors affecting the overall survival, toxicity during anticancer treatment, and quality of life among patients with cancer. Previous studies have shown that the increased protein intake can stimulate muscle synthesis, and improve muscle mass, strength, function, overall survival, and quality of life. The current study is going to investigate the effectiveness and safety of protein supplements on patients with cancer, in order to provide a reference for further nutrition treatment.

An anticipated total of 100 participants will randomly assigned to receive either a 20-gram protein supplement per day or nutrition counseling to increase the protein intake. there will be a total of 3 study visits, and dietary assessment and blood sample collection will occur at every study visit. Intention-to-treat analysis (ITT) and per-protocol analysis (PP) will be used in statistical analysis.

Inclusion Criteria:

• • Age>=18years old;

  • Initial treatment patients with lung/gastrointestinal/esophageal cancer
  • Patients with nutritional risk (NRS-2002≥3) ;
  • Patients are able to provide written informed consent.

Exclusion Criteria:

• • People who are allergic to whey protein.

  • Participants received any drugs or supplements known to influence the outcomes, such as protein powder, anabolic steroids, or glucocorticoids before the 3 months preceding the study.
  • Participants with gastrointestinal bleeding or intestinal obstruction, or any contraindication for oral intake
  • Concurrent severe cardiac disease, liver and renal failure, which may significantly interfere with study compliance.
  • Participants with electronic or mental device.
  • Women in pregnancy or lactation period