Would losing weight after a tummy tuck and breast reduction ruin the result?

Congratulations on your weight loss thus far! Although it is ideal to come as close as possible to your target weight before getting a mommy makeover, excess skin can make exercise very difficult. You are however, within a close enough window to your target weight that you could schedule a consultation with a board-certified plastic surgeon for an evaluation and to discuss your mommy makeover timeline. After a physical examination, he or she can best advise as to whether or not moving forward with your procedure now would yield the best results. Good luck!

hello thank you for your question and provided information as well.. based in your question its difficultd evaluated you if the case dont have a picture , its recommended get a consultation with a plastic surgeon to evaluate you.

Thank you for your question!
To get the best results you should be on your desired weight for 3 to 6 months, I'm sorry that  you are having trouble with the last 20 pounds. However, I don't think that 20 pounds could ruin your result, if you have been in the same weight for at least 3 months then you are ready to go on with the surgery, the worst that can happen is if you lose 20 pounds more after surgery and you have some redundant or saggy skin again it can be fixed with a minor procedure. Be sure to discuss your goals and expectations with your plastic surgeon and follow all the instructions before and after your surgery. 

I hope this is useful, wish you the best