Non-linear relationship between the first meal time of the day and gallstone incidence in American adults: a population-based cross-sectional study - Sun, Tiange; Zhang, Lidong; Lu, Ying; Zhang, Xianwen; Cui, Jinhao; Yang, Tongheng; Zhang, Dan; Zheng, Bowen; Zheng, Shuguo (Frontiers in Nutrition, 2024)