Serum phosphate concentrations are not only associated with cardiovascular and all-cause mortality in chronic kidney disease (CKD) patients, but also associated with the mortality in community population. Thus, maintaining normal serum phosphate and reducing postprandial fluctuation of serum phosphate are essential for healthy people.~The investigators have conducted a study about the effects of normal diet (phosphorus 1500mg) and low-phosphorus diet (phosphorus 500mg) on phosphorus homeostasis in healthy men. The results showed low-phosphorus diet could significantly reduce serum phosphorus and urine phosphorus level compared to normal diet. However, the levels of serum FGF23 and a-klotho were not different between these two groups.Thus, the investigators want to further explore the effects of high-phosphorus diet (phosphorus 2300mg)on phosphorus homeostasis in healthy men.~Therefore, the investigators plan to conduct a crossover clinical study to evaluate the phosphorus homeostasis modulated by native normal diet, restricted phosphorus diet, high phosphorus diet and then to explore the underlying mechanisms.
The investigators have conducted the study about the effects of normal diet and low-phosphorus diet on phosphorus homeostasis in healthy subjects, now this study is designed to explore further about the effect of high-phosphorus diet on phosphorus homeostasis.