The Combined Effect of Dietary and Behavioral Risk Factors in Gastric Cancer: A Case-Control Study Using a Healthy Lifestyle Index in Fujian, China

Background/Objectives: Gastric cancer (GC) remains a major health challenge in high-incidence regions like Fujian Province, China. This study aimed to identify modifiable dietary and behavioral risk factors for GC and to evaluate their combined effect using a Healthy Lifestyle Index (HLI) in a high-incidence region of China. Methods: A case–control study was conducted at a tertiary hospital from June 2023 to December 2024, including 336 newly diagnosed GC cases and 336 healthy controls from Fuji