BMI and weight stability

Why BMI matters in body contouring

BMI is an imperfect measure of body composition, but it correlates strongly with complication rates in body contouring. The reasons:

• Increased operative complexity. Larger skin envelopes require longer operative time. Each additional unit of BMI adds time, tissue dissection, and exposure.
• Higher rate of wound healing problems. Subcutaneous tissue has lower vascular density than skin and muscle. Higher BMI means more subcutaneous tissue and proportionally less reliable blood supply at incisions.
• Higher DVT and PE risk. BMI is an independent risk factor for thromboembolism in the perioperative period.
• More residual contour irregularity. Higher BMI means more underlying fat that cannot be addressed by skin excision; the result is less dramatic.

BMI thresholds

Approximate guidelines for elective body contouring:

• <30: Optimal for body contouring. Standard risk profile.
• 30–32: Acceptable for most procedures with conventional perioperative care. Slightly elevated complication rates.
• 32–35: Case-by-case. Many surgeons accept this range with caution; complication rates are meaningfully elevated.
• >35: Body contouring complications become unacceptable for elective surgery. Patients in this range are usually asked to lose further weight before proceeding.

Why weight stability matters

Body contouring removes excess skin and fat sized to the patient's current weight. If weight subsequently changes:

• Weight gain stretches the surgical result and may distort scars.
• Continued weight loss produces new redundancy that the original procedure could have addressed if it had been postponed.

Stability for 6 months minimum (ideally 12) before surgery is the standard. For patients still actively losing weight, deferral until weight stabilises is almost always the right answer.