Weight lost code

I am creating a chart.

Here is my scenario.

Cell A1 I entered 170 starting weight and in Cell B1 I will be entering 165 new weight so then the result weight should show -5 of lost weight (with a negative sign) in cell C1. If I entered 175 in cell B1 it should show +5 (with a possitive sign).
In cell H1 need a code a total percentage of lost weight.
If you can please create me a code in C1 to show the result of negative or positive result.

Thank you

in C1

=A1-B1

=In H1

=C1/A1 format as percentage

See attached, take a look at the formula line - but it is as above, with the cells formatted.