This was the first comprehensive study to explore effects of SGLT-2 inhibitors on weight in T2DM; meanwhile, the optimum dosages and treatment durations on weight from canagliflozin, empagliflozin, ertugliflozin, ipragliflozin, luseogliflozin, and tofogliflozin were recommended, respectively. This evidence concerns the gene SLC5A2 and type 2 diabetes mellitus.