Efficacy of low-protein diet for diabetic nephropathy: a systematic review of randomized controlled trials oleh Huan-gao Zhu, Zhao-shun Jiang, Pi-yun Gong, Dong-mei Zhang, Zhi-wei Zou, Qian-Zhang, Hui-mei Ma, Zhen-gang Guo, Jun-yu Zhao, Jian-jun Dong, Lin-Liao