Should I improve my appearance by adopting a healthy lifestyle, or just go ahead and get the cosmetic surgery?

Lifestyle first. It is in your best interest to adopt the healthy lifestyle first and use cosmetic surgery to accomplish goals which cannot otherwise be achieved.
Lifestyle 1st. For many reasons, it is best to “adopt a healthy lifestyle” prior to undergoing any type of cosmetic surgery. The best candidates for cosmetic surgery tend to be patients who are at their optimal medical, psychological, and psychosocial “health”. These patients present with “problem areas” that are resistant to improvement despite their healthy lifestyles. Best wishes.
Health-style trumps. It is always advisable to be in optimal shape before any surgery. Cosmetic surgery is not a replacement for taking great care of your body with proper nutrition, exercise, non-smoking, limiting alcohol intake and being psychological healthy. Cosmetic surgery will improve the outer physical appearance but true beauty comes from within. Combine them both and you look and feel wonderful.
Why not both? A healthy lifestyle is the obvious choice here, but it is not an either/or situation.
Depends on problem. A healthy lifestyle is very important for all of us but it can't fix everything so you have to give more info.
Lifestyle first. Diet and exercise are always the first line to improve appearance. The patient will also be healthier all around. After this, if the paitent still wants surgery, the procedure usually gets a better result, with less stress on the patient. We send patients to the gym and have them come back to us for progress checks all the time.
Yes. That's never a bad idea but won't usually resolve what the patient is concerned about.
Yes. Cosmetic surgery is typically more successful once a patient has achieved a stable healthy weight pre-operatively. For example, losing as much weight as you can before a tummy tuck or a breast reduction will only improve your results. Most plastic surgeons will advise their patients to lose as much weight as possible and, more importantly, achieve a stable weight before undergoing surgery.