Nutrition and Lifestyle Study Cohort of Gastric Cancer in China

China has the largest gastric cancer patients population all over the world. Recent reports concluded nutrition status and lifestyle factors were associated with gastric cancer risk, however, the influence of nutrition and lifestyle factors on cancer outcome in gastric cancer survivors is largely unknown.The investigators will explore the impact of nutrition status, life style, dietary pattern, obesity, physical activity, depression, diabetes, aspirin use and vitamin supplement on gastric cancer outcome. The investigators will recruit approximately 50,000 patients as a prospective study cohort. During follow up, the investigators will explore the association of these factors with disease-specific survival, disease-free survival and overall survival of patients. The investigators believe that this project will facilitate the establishment of domestic nutrition and lifestyle data of gastric cancer of China, and the improvement of the quality of clinical management of patients with gastric cancer.