If I lose 20 lbs after my tummy tuck will that ruin my results? (photos)

You appear to be in excellent shape to u derogatory a tummy tuck.  If you lose more weight after the tummy tuck, it probably won't cause a problem.  A more common problem we see is weight GAIN after a tummy tuck, so make sure that you at least maintain your weight and don't gain any.

Congratulations on your weight loss. Most plastic surgeons suggest that you finish
having children and get your weight within 10 pounds of your ideal weight
before undergoing an abdominoplasty with repair of the stretched out abdominal
muscles , in order to achieve the best long
term cosmetic result with the least potential complications.Losing weight after surgery may compromise your results.

Following the advice of anyone who would presume
to tell youwhat to do based on two dimensional photos without taking a
full medical history, examining you, feeling and assessing your tissue tone,
discussing your desired outcome and fully informing you about the pros and cons
of each option would not be in your best interest. Find a plastic surgeon that
you are comfortable with and one that you trust and listen to his or her
advice.The surgeon should be certified by the American Board of Plastic Surgery
and ideally a member of the American Society for Aesthetic Plastic Surgery
(ASAPS). If you live outside of the United States, the surgeon should
ideally be a member of the International Society of Aesthetic Plastic Surgery
(ISAPS). You should discuss your concerns with that surgeon in person.

Robert Singer, MD FACS

La Jolla, California.