BMI & Body Weight Considerations for Surgery

Medically reviewed by Jennifer Richman, PA on October 1, 2024.

In this article, we go over the most common questions and concerns patients have about how Body mass index (BMI), body fat and how changes in body weight can affect a patient’s eligibility for and results from gender-affirming surgery.

Will BMI impact my eligibility for surgery?

Weight in itself is not the sole restrictive factor in determining one’s eligibility for a particular procedure. Decisions are always made in light of you as a whole and certainly, it is not a point to be dismissed whether one’s weight is “too high” or “too low.” 

BMI (Body Mass Index) is often brought up in this conversation. The original intention of this metric was never to assess one’s general health status. It is calculated as weight divided by height and based on the result a person is assigned this BMI number and a label as a category.

However, even the CDC agrees that BMI in itself does not necessarily correlate with one’s health status or even level of obesity. Providers must consider a broader picture in assessing a patient’s health and better determinants are more physiologic parameters like, for example, vital signs, age, medical conditions, and of course lifestyle seem to play a more important role in a person’s health status.

The GCC is one of the only gender-competent surgical practices that does not discriminate against patients for their BMI. Historically, we have had several successful cases of top surgery for patients with BMIs over 35. Depending on a patient’s medical history, we may take extra precautions like asking a patient to stay an extra night in the hospital to monitor their health after surgery.

What are the BMI guidelines for getting gender-affirming surgery?

We do have BMI eligibility restrictions for certain procedures. It is important to note that body composition, not the weight itself, is a major determinate. BMI itself does not reflect this point. If you have specific questions, you can discuss them with one of our board-certified surgeons in a free, virtual consultation.

• Anesthesia requirements: While the GCC does not impose BMI cutoffs for top surgery and facial surgery patients who have gone through a thorough medical clearance process, there still exist limits that may be imposed by the hospital anesthesia departments. Patients with a BMI >60 may not receive approval to proceed with surgery based on safety concerns and functional limitations that may make it difficult to properly ventilate–i.e., provide adequate air to the lungs–during surgery. Our surgeons and medical team can work with you to explain the process and determine how best to proceed.
• Top surgery and facial surgeries: There are no strict BMI limitations for chest reconstruction, breast reduction, breast augmentation and facial surgeries. However, an overnight stay or surgery in a hospital (as opposed to a surgical center) may be required due to existing comorbidities.

• Body contouring: BMI limitations for body contouring procedures have less to do with medical necessity to qualify for surgery and more to do with accomplishing realistic goals. Generally speaking, patients with BMIs over 32 might have limited or minimal results. If you have specific questions about how you can meet your body contouring goals given your body type, we encourage you to request a free, virtual consultation with one of our surgeons.

• Bottom surgeries: In this category of surgeries, weight and body composition plays a greater role in determining candidacy or eligibility. Though a physical exam is required to assess readiness and risk for bottom surgery, we can provide general ranges that we use as guides for the procedures we offer:

• • Simple metoidioplasty: ≤40
  • Groin-flap phalloplasty: ≤32
  • Metoidioplasty with urethral lengthening: ≤35
  • ALT (anterolateral thigh) phalloplasty: ≤32
  • Microsurgical phalloplasty: ≤32
  • Vaginoplasty: ≤36
  • Vulvoplasty: ≤40

What health concerns exist for surgical patients with high and low BMIs?

Some health conditions frequently associated with underweight or overweight BMIs may increase the risk of complications such as respiratory problems, skin infections, wound dehiscence (opening of the wound), bleeding or clotting. Generally speaking, patients with high ammounts of fat have an increased risk of anesthesia-related complications, such as difficulties in airway management, impaired lung function, and a higher likelihood of developing blood clots or respiratory issues during and after surgery.

The majority of concerns we navigate with patients that have high, “normal,” and lower BMIs have to do with comorbidities or other health conditions. Accompanying health issues like diabetes, high blood pressure, heart problems, pulmonary hypertension and others can be treated and met with specific medical interventions to minimize your surgical risks. We are dedicated to providing safe medical care while simultaneously reducing barriers to receiving gender-affirming care.

To manage your health risks, it is important that your surgical team performs a thorough review of your medical history. Oftentimes, collaboration or specialized testing with primary care providers, cardiologists, endocrinologists, anesthesiologists or other medical specialists will be necessary before and/or after surgery to optimize patient health and safety for patients with either elevated (“overweight or obese”) or low (“underweight”) BMIs to ensure there are no signs of malnutrition or underlying systemic disease. Results of these exams will be used to create a unique surgical plan to maximize your safety and the integrity of your results.

In the informational video below, Dr. Jacobs (he/him) describes how our practice plans around the risks associated with undergoing surgery with a BMI over 30 without denying our patients access to gender-affirming care.

How might weight fluctuation change my surgical results?

A patient’s weight can also have implications on their overall aesthetic results after surgery. Large fluctuations in weight after surgery can alter the appearance of the chest, as the skin and fat layer underneath, called the subcutaneous fat. Rapid changes in weight can alter the integrity of the skin and make it more prone to stretch marks or stretching of any post-surgical scars. For specific information on how weight fluctuation can alter your body contouring results, click here.

Differences in weight can also impact healing times and return to normal activity after surgery. To avoid any unwanted changes in the aesthetic result after surgery, we recommend that patients demonstrate a stable weight for at least 3-6 months prior to surgery. In some scenarios, this may be longer. For patients undergoing an elective or medically monitored weight-loss or weight-gain journey, we recommend this be completed prior to surgery if appropriate.