The purpose of this study is to determine whether positive lifestyle interventions (diet modification and smoking cessation) are effective in the prevention of gastric pre-cancer and cancer occurrences and reccurence of gastric cancer after endoscopic resection.

Inclusion Criteria:

• diagnosis of chronic atrophy gastritis proved by gastroscopy biopsy pathology or early gastric cancer patients who have recieved endoscopic resection
• have one or several bad lifestyle habits such as eating too much salt, eating too few fruits, smoking, drinking wine, and lack of sleep.

Exclusion Criteria:

• patients who refuse to change lifestyle according to the trial plan