Hi Si, Thank you for your question regarding a flabby belly after teen weight loss and how to tighten it up. Initially, we must evaluate your photographs to determine the most effective methods. Your lower abdomen is affected by dermatocholosis (loose skin) and cutis pleonasmus (excess skin). You are not affected by lipodystrophy or excessive body fat. Consequently, you are experiencing a skin issue rather than a fat issue. Liposuction would not be the optimal procedure for you, as it removes fat rather than skin. Consequently, an abdominal tuck or abdominoplasty would be the optimal course of action for you. A tummy tuck is conducted under general anesthesia and typically requires three to four hours to complete. An incision is made in the abdominal wall at a low level. The umbilicus is the site of tissue dissection. The navel button is dissected from the abdominal wall after an incision is made around it. Dissection of tissue proceeds to the sternum. The rectus muscle is examined. Typically, the rectus muscle is plicated or sutured together to remedy for rectus diastasis and flatten the abdomen. Your rectus muscle is in excellent condition; therefore, muscle plication is unnecessary. The excess abdominal wall skin and adipose tissue are removed, and the abdominal wall skin is redraped. The two drains are typically removed after 10 to 14 days. After approximately 2 weeks, most patients are able to resume their daily activities. After approximately six to eight weeks, the majority of patients are capable of resuming their typical exercise regimen. An alternative to plastic surgery is exercise. Weight lifting to increase bulk may be an option. However, due to your genetics and age, your skin may not completely bounce back. Most plastic surgeons would agree that you should give yourself 8 to 12 months for dedicated weight lifting. If you do not achieve your results by then, you may want to consider plastic surgery. If you have any more questions regarding tummy tucks, abdominoplasties, or abdominal liposuction, contact an experienced plastic surgeon Since the tummy tuck surgery is a big procedure, please seek an experienced, board-certified plastic surgeon with significant experience in performing tummy tucks. Do your research. If you cannot find an experienced tummy tuck plastic surgeon in your neighborhood, consider traveling out of state. Sincerely, Dr. Katzen, MD, MBA, FACS, FICS. ( Plastic Surgeon, President of the American Society of Bariatric Surgeons, certified by the American Board of Plastic Surgery, Fellow of the International Society of Aesthetic Plastic Surgery, American College of Surgery, and International College of Surgery and member of the American Society of Plastic Surgery, American Academy of Cosmetic Surgery, RealSelf Hall of Fame, and RealSelf Doctor Advisory Board for Medical Review and Consumer Panel.)