I'm 5"7 weigh 224 lbs. with breast size 40F. How much weight should be lost before starting the process for a Breast Reduction

While it is ideal to lose weight prior to surgery, this is often difficult or impossible for most patients. This is mainly true as exercising is especially difficult with enlarged breasts. I would recommend seeing a board-certified plastic surgeon for consultation to discuss options of breast reduction surgery before or after weight-loss.

Many women find exercise difficult because of the way to the breasts. Breast reduction can make exercising easier encouraging subsequent weight loss.

Normally the process for a breast reduction entails preauthorization from your insurance company.  Each insurance company has their own particular criteria for determining whether or not they will pay for the procedure.  Commonly they make a calculation based on your height and weight which determines how much weight needs to be removed from your breasts.  It may be you'll need to lose weight in order to satisfy the criteria of your insurance company.  In general it is best to be within 10 pounds of your target weight before undergoing any type of body contouring procedure.

you must  loose no less than 25 lbs in order  to get a  wonderfull result as soon as you  have gotten  this weight you  should  begin  your planification  for  breast reduction  and  lifting

It would be helpful to lose about 30 pounds to get your BMI below 30 before you consider a breast reduction.  If you can not lose weight the a breast reduction is possible but there are increased risks due to your weight.  

You should get to a weight that you are comofrtable at before udnergoing a breast reduction. Your breasts may shrink if you have surgery first and then lose weight.

You do not necessarily have to lose any more weight prior to breast reduction, although it would probably make healing a bit safer and easier.  Losing weight after breast reduction is more of a problem in my practice.  When this occurs, your breast will seem too small (assuming a weight loss of more than 20-25 pounds).  Overall, I would try to be at a weight that you can live with before your breast reduction.