How much weight to lose?

Everybody thinks they need to lose some amount. Most if not all will guess a number

much smaller then you actually need.

The truth is that you need to determine how much fat you actually have on you.

There are several ways to do this most common is the bioimpedance weigh scales.

or the fat analyser scales that you can buy at the store. These aren't too accurate but

their cheap for their purpose and gives you a general guideline. There are more expensive 

and more pain the butt methods, like submersion and some new fangled dual x-ray scan thingy.

However you get this measurement, lets say its X % .. (for discussion purpose 35%)

That means 35% of your body weigh is fat.

So if you weigh 100kg or 220pounds 35% is 

 0.35 x100Kg or 0.35 x 220 pounds

= 35kg or 77 pounds.

So now you know your lean body mass is simply your weight - this fat .

So 100kg-35kg= 65kg lean body mass. or 220-77 = 143 pounds.

Now for men the ideal fat % is actually 15 % and for women its 20%.

For easy calculation just divide the lean body weight by (0.85 for men) or (0.8 for women)

That gives

For men : 76kg or 168 pounds

For women: 81kg or 178 pounds.

So now that you know your ideal weigh.. you know how much you need to lose.