Your bathroom scale is lying to you: You don't "weigh" 60kg.

In physics and math, Mass (m) is the amount of matter you contain (measured in kg), while Weight (W) is a force (measured in Newtons)

If you went to the Moon, your mass would be exactly the same, but your weight would drop by 83%. If you were in deep space, you would weigh 0 Newtons, but your mass—and the energy required to move you (F=ma) would remain unchanged. People say "I want to lose weight," but scientifically, they mean they want to lose mass.