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Patient-Centered Approaches to Using BMI to Evaluate Gender-Affirming Surgery Eligibility

Learning Objectives
1. Explain a new or unfamiliar viewpoint on a topic of ethical or professional conduct
2. Evaluate the usefulness of this information for health care practice, teaching, or conduct
3. Decide whether and when to apply the new information to health care practice, teaching, or conduct
1 Credit CME

Body mass index (BMI) cutoffs are routinely used to assess eligibility for gender-affirming surgeries (GAS), yet they are not empirically based. The transgender population is disproportionately affected by overweight and obesity due to clinical and psychosocial influences on body size. Strict BMI requirements for GAS are likely to cause harm by delaying care or denying patients the benefits of GAS. A patient-centered approach to assessing GAS eligibility with respect to BMI would utilize reliable predictors of surgical outcomes specific to each gender-affirming surgery, include measures of body composition and body fat distribution rather than BMI alone, center on the patient's desired body size, and emphasize collaboration and support if the patient genuinely desires weight loss.

Assessing Eligibility

The number of transgender patients seeking gender-affirming surgery (GAS) has dramatically increased in recent years.1 Body mass index (BMI) cutoffs are routinely used to assess eligibility for GAS due to concerns about adverse surgical outcomes.24 Results from the National Surgical Quality Improvement Program revealed that the effect of BMI on surgical outcomes presents the greatest risk to patients with morbid obesity (BMI ≥ 40). Commonly cited concerns include increased risk of surgical site infection; cardiovascular risks, such as cardiac arrest and myocardial infarction; and pulmonary complications, such as pneumonia, reintubation, and prolonged ventilator support.5,6

Risks associated with delaying or denying access to GAS are also salient. Gender-affirming medical interventions, including hormone therapy (HT) and GAS, are associated with improved quality of life and decreased levels of anxiety, depression, gender dysphoria, and suicidal ideation.79 The eighth version of the World Professional Association of Transgender Health guidelines characterize GAS as “medically necessary” for some patients to alleviate gender dysphoria.10 Thus, surgeons must consider not only the risks of the surgery itself, but also the risks to a patient's health and well-being when GAS is delayed or denied.

The purposes of this article are (1) to review the existing research on BMI as a predictor of GAS outcomes using a mapping review; (2) to discuss weight disparities among the transgender population; and (3) to advance discussion of how to evaluate patients' eligibility for GAS with particular attention to their body size in light of calls for a “multimodal, human-centered approach” to addressing risk factors for GAS.2

Results of a Mapping Review

Table 1 provides brief definitions of various chest and genital GAS.

Table 1. Brief Definitions of Gender-Affirming Surgeries

Surgical ProcedureDefinition
Masculinizing Surgery
HysterectomyRemoval of the uterus
Implantation of erection prosthesisAddition of a penile implant, often as part of a phalloplasty
Mastectomy or chest reconstructionRemoval of breast/chest tissue
MetoidioplastyCreation of a penis using existing genital tissue
Ovariectomy or oophorectomyRemoval of one or both ovaries
PhalloplastyCreation of a penis
ScrotoplastyCreation of a scrotum
VaginectomyRemoval of all or part of the vagina
Feminizing Surgery
Augmentation mammoplastyIncrease in breast/chest size
ClitoroplastyCreation of a clitoris
OrchiectomyRemoval of one or both testicles
PenectomyRemoval of a penis
VaginoplastyCreation of a vagina using existing genital tissue
VulvoplastyCreation of a vulva

To review existing research on BMI as a predictor of GAS outcomes, we conducted a mapping review of the available literature published through July 1, 2022. A mapping review is ideal to categorize existing literature, identify gaps, and guide further research.11 We searched the Scopus database using queries with keywords: the name of the surgical procedure (eg, mastectomy) AND body mass index OR obesity OR body weight AND transgender. Studies were screened to remove those that reported BMI or weight status in the sample population but did not evaluate the role of BMI in predicting GAS outcomes.

Table 2 presents a summary of the articles retrieved from our search. In total, 11 studies explored the role of BMI in predicting chest and genital GAS outcomes.Quiz Ref ID

Table 2. Summary of Studies That Investigated the Role of BMI on Predicting Breast/Chest and Genital GAS Outcomes

Surgical ProcedureStudiesStudy DesignResults
Masculinizing GASa
Mastectomy, chest reduction, or musculoplastyCuccolo (2019)Retrospective chart review of 755 patientsObesity was more prevalent among patients who underwent breast/chest reduction compared to those who underwent a mastectomy, but complication rates did not differ between the two cohorts.
Knox et al (2017)Retrospective chart review of 101 patientsConcentric circular technique presented greater risk of complications compared to free nipple graft technique in patients with a BMI > 27 kg/m and additional factors.
Pittelkow (2020)Retrospective chart review of 145 patientsPostoperative infections were significantly increased in patients with morbid and super obesity, but not in patients with obesity.
Rothenberg (2021)Retrospective chart review of 948 patientsThere were no significant differences in complications or revisions between patients with obese versus those with a normal BMI.
Stein (2021)Retrospective chart review of 97 patientsMinor and major complication rates did not differ between patients with obesity and those without obesity
HysterectomyFerrando (2021)Retrospective chart review of 67 patientsBMI was not associated with increased incidence of intraoperative endometriosis or heavy bleeding.
MetoidioplastyWatershoot (2021)Retrospective chart review of 74 patientsBMI was not a predictor of complications.
Feminizing GASb
VaginoplastyBuncamper (2016)Retrospective chart review of 475 patientsBMI was not associated with complications.
Gaither (2018)Retrospective chart review of 330 patientsBMI was not associated with complications.
Ives (2019)Retrospective chart review of 101 patientsBMI was not associated with delayed revision urethroplasty or complications.
Procedure type not specifiedScott (2022)Analysis of American College of Surgeons NSQIP DataBMI was positively associated with an increased risk for having at least one complication.

Five studies focused on masculinizing chest surgeries, such as mastectomy, breast reduction, or musculoplasty.1216Quiz Ref IDAn obese BMI (≥ 30) did not increase the risk of complications in 4 of the 5 chest reconstruction studies.12,1416 Pittelkow et al found that postoperative infection risk was higher in mastectomy patients with morbid obesity (BMI ≥ 40) and super obesity (BMI ≥ 50).14 BMI was not associated with complications in studies of hysterectomy,17 metoidioplasty,18 and vaginoplasty.1921 Among all forms of gender-affirming surgery, BMI was associated with a very slight increased risk for complications in Scott et al's study that relied on American College of Surgeons National Surgical Quality Improvement Program data, although the findings were not reported by BMI classification, type of gender-affirming surgery, or the nature of the complication.1

The studies identified in this literature review have several limitations. Because existing research is limited to 4 common GAS, future research should address BMI as a predictor of outcomes in all forms of gender-affirming surgery. A second limitation is that because BMI cutoffs were routinely used to determine GAS eligibility when some of the studies were performed,2,4 patients with higher classes of obesity might not have been included in the study samples. Thus, further research should explore BMI as a predictor of GAS outcomes in patients with class I, II, and III obesity, similar to the work of Rothenberg et al15 and Pittelkow et al,14 and in patients with an underweight BMI (< 18.5).

Weight-Related Inequity

Quiz Ref IDA patient-centered approach to evaluating GAS eligibility with respect to BMI requires consideration of multiple influences on body weight and obesity risk. Transgender individuals are more likely to be affected by overweight and obesity than nontransgender individuals secondary to clinical and psychosocial factors.2225 For example, masculinizing and feminizing HT result in estimated increases in body weight of 1.7 kg and 1.8 kg, respectively,26 with case reports of up to 27.3 kg of weight gain.27 Anticipated weight gain with HT increases the likelihood that a patient's BMI would exceed predetermined limits for GAS. In addition, the transgender population is disproportionately affected by nutrition-related conditions, such as food insecurity and eating disorders,2832 both of which are associated with an increased obesity risk in certain population groups.3335 The transgender population is also significantly less physically active than the cisgender population due to fear of being “outed” as transgender, “passing” as male or female, and body dissatisfaction, among other factors.3638,4044 Although obesity is a complex disease, physical inactivity is a known risk factor.25

A Patient-Centered Approach

Although the terms obese and obesity have been used throughout this paper when describing the results of existing research reliant on Centers for Disease Control and Prevention BMI ranges, we recognize that obesity as a medical diagnosis lacks sensitivity to body size diversity. Strict BMI requirements for GAS and routine weight loss recommendations also neglect a fundamental consideration: the patient's own desire for their body size. Quiz Ref IDThe hegemonic assumption is that all patients desire a body size that is within the “healthy” BMI range of 18.5-24.9 as defined by the Centers for Disease Control and Prevention,39 despite the known limitations of BMI as a predictor of adiposity and health outcomes.45 Whether the patient with a BMI classified as overweight or obese genuinely desires a smaller body size, however, is not routinely considered. Notably, the patient's desire for their own body size does not change the risks associated with GAS, but it is relevant to the provision of patient-centered care.

Body size and shape may be an expression of a patient's authentic gender identity. The first author (W.L.) and a colleague have related the narrative of a transgender man who genuinely desired a larger body size—which he described as “having more of a presence,” “filling out my space,” and “going from invisible to visible”—when he decided to transition.46 Although clinicians would label his body as obese, his larger body size was an expression of his masculinity.46 Importantly, emerging research suggests that prescribing weight loss for patients seeking GAS is not only ineffective but also may cause harm by propagating weight cycling and weight stigma.2,47 Thus, while many patients with overweight or obesity may genuinely desire a smaller body size, the reflexive assumption that all patients are dissatisfied with their body size lacks sensitivity to patients' goals and gender expression.

A patient-centered approach to assessing GAS eligibility with respect to BMI would be empirically driven and center on the patient's goals for their body. Toward this end, clinicians can employ the strategies depicted in the Figure.Quiz Ref ID

Figure. Patient-Centered Approach to Use of Body Mass Index in Evaluating Gender-Affirming Surgery Eligibility

The use of BMI cutoffs to determine GAS eligibility is an oversimplified and unsubstantiated practice. Given that transgender individuals are disproportionately affected by obesity, strict BMI requirements for GAS are likely to harm a significant number of patients by delaying or denying the benefits of GAS. A patient-centered approach to assessing GAS eligibility with respect to BMI would utilize reliable predictors of surgical outcomes specific to each gender-affirming surgery, include measures of body composition and body fat distribution rather than BMI alone, center on the patient's desires for their body size, and emphasize collaboration and support if the patient genuinely desires weight loss. Further research is needed to determine reliable predictors of various GAS.

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The AMA Journal of Ethics exists to help medical students, physicians and all health care professionals navigate ethical decisions in service to patients and society. The journal publishes cases and expert commentary, medical education articles, policy discussions, peer-reviewed articles for journal-based, video CME, audio CME, visuals, and more. Learn more

Article Information

AMA Journal of Ethics

AMA J Ethics. 2023;25(6):E398-406

AMA CME Accreditation Information

Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships.

If applicable, all relevant financial relationships have been mitigated.

Conflict of Interest Disclosure: The author(s) had no conflicts of interest to disclose.

The viewpoints expressed in this article are those of the author(s) and do not necessarily reflect the views and policies of the AMA.

Author Information:

  • Whitney Riley Linsenmeyer, PhD, RD, LD is an assistant professor of nutrition at Saint Louis University in St Louis, Missouri, and a spokesperson for the Academy of Nutrition and Dietetics. Her research and clinical practice center on nutrition care for the transgender population; Sarah Garwood, MD is an associate professor of pediatrics at Washington University School of Medicine's Division of Adolescent Medicine and co-director of the Washington University Transgender Center at St Louis Children's Hospital in Missouri. She also serves as medical director of The SPOT at Jennings High School, the first comprehensive school-based health center in St Louis County.

Scott  KB, Thuman  J, Jain  A, Gregoski  M, Herrera  F.  Gender-affirming surgeries: a national surgical quality improvement project database analyzing demographics, trends, and outcomes.  Ann Plast Surg. 2022;88(5)(suppl 5):S501–S507.Google Scholar
Brownstone  LM, DeRieux  J, Kelly  DA, Sumlin  LJ, Gaudiani  JL.  Body mass index requirements for gender-affirming surgeries are not empirically based.  Transgend Health. 2021;6(3):121–124.Google ScholarCrossref
Chen  ML, Reyblat  P, Poh  MM, Chi  AC.  Overview of surgical techniques in gender-affirming genital surgery.  Transl Andol Urol. 2019;8(30):191–208.Google Scholar
Van der Sluis  WB, de Bruin  RJM, Steensma  TD, Bouman  MB.  Gender-affirmation surgery and bariatric surgery in transgender individuals in The Netherlands: considerations, surgical techniques and outcomes.  Int J Transgend Health. 2021;23(3):355–361.Google ScholarCrossref
Tsai  A, Schumann  R.  Morbid obesity and perioperative complications.  Curr Opin Anaesthesiol. 2016;29(1):103–108.Google ScholarCrossref
Sood  A, Abdollah  F, Sammon  JD,  et al.  The effect of body mass index on perioperative outcomes after major surgery: results from the National Surgical Quality Improvement Program (ACS-NSQIP) 2005-2011.  World J Surg. 2015;39(1):2376–2385.Google Scholar
Bailey  L, Ellis  SJ, McNeil  J.  Suicide risk in the UK trans population and the role of gender transition in decreasing suicidal ideation and suicide attempt.  Ment Health Rev. 2014;19(4):209–220.Google ScholarCrossref
Heylens  G, Verroken  C, De Cock  S, T'Sjoen  G, De Cuypere  G.  Effects of different steps in gender reassignment therapy on psychopathology: a prospective study of persons with a gender identity disorder.  J Sex Med. 2014;11(1):119–126.Google ScholarCrossref
Nibili  A, Glazebrook  C, Arcelus  J.  Quality of life in treatment-seeking transgender adults: a systematic review and meta-analysis.  Rev Endocr Metab Disord. 2018;19(3):199–220.Google ScholarCrossref
Coleman  E, Radix  AE, Bouman  WP,  et al.  Standards of Care for the Health of Transgender and Gender Diverse People, version 8.  Int J Transgend Health. 2022;23(suppl 1):S1–S259.Google Scholar
Grant  MJ, Booth  A.  A typology of reviews: an analysis of 14 review types and associated methodologies.  Health Info Libr J. 2009;26(2):81–108.Google Scholar
Cuccolo  NG, Kang  CO, Boskey  ER,  et al.  Masculinizing chest reconstruction in transgender and nonbinary individuals: an analysis of epidemiology, surgical technique, and postoperative outcomes.  Aesthetic Plast Surg. 2019;43(6):1575–1585.Google Scholar
Knox  AD, Ho  AL, Leung  L,  et al.  A review of 101 consecutive subcutaneous mastectomies and male chest contouring using concentric circular and free nipple graft technique in female-to-male transgender patients.  Plast Reconstr Surg. 2017;139(6):1260e–1272e.Google Scholar
Pittelkow  EM, Duquette  SP, Rhamani  F, Rogers  C, Gallagher  S.  Female-to-male gender-confirming drainless mastectomy may be safe in obese males.  Aesthet Surg J. 2020;40(3):NP85–NP93.Google Scholar
Rothenberg  KA, Gologorsky  RC, Hojilla  JC, Cohan  CM, Beattie  G, Yokoo  KM.  Gender-affirming mastectomy in transmasculine patients: does obesity increase complications or revisions?  Ann Plast Surg. 2021;87(1):24–30.Google Scholar
Stein  JM, Grigor  E, Hardy  J, Jarmuske  M.  Surgical and patient-reported outcomes following double incision and free nipple grafting for female to male gender affirmation: does obesity make a difference?  J Plast Reconstr Aesthet Surg. 2021;74(8):1743–1751.Google Scholar
Ferrando  CA, Chapman  G, Pollard  R.  Preoperative pain symptoms and the incidence of endometriosis in transgender men undergoing hysterectomy for gender affirmation.  J Minim Invasive Gynecol. 2021;28(9):1579–1584.Google Scholar
Waterschoot  M, Hoebeke  P, Verla  W,  et al.  Urethral complications after metoidioplasty for genital gender affirming surgery.  J Sex Med. 2021;18(7):1271–1279.Google Scholar
Buncamper  ME, van der Sluis  WB, van der Pas  RSD,  et al.  Surgical outcome after penile inversion vaginoplasty: a retrospective study of 475 transgender women.  Plast Reconstr Surg. 2016;138(5):999–1007.Google Scholar
Gaither  TW, Awad  MA, Osterberg  EC,  et al.  Postoperative complications following primary penile inversion vaginoplasty among 330 male-to-female transgender patients.  J Urol. 2018;199(3):760–765.Google Scholar
Ives  GC, Rein  LA, Finch  L,  et al.  Evaluation of BMI as a risk factor for complications following gender-affirming penile inversion vaginoplasty.  Plast Reconstr Surg Glob Open. 2019;13(7):e2097.Google Scholar
Warren  JC, Smalley  KB, Barefoot  KN.  Differences in psychosocial predictors of obesity among LGBT subgroups.  LGBT Health. 2016;4(3):283–291.Google Scholar
Linsenmeyer  WR, Katz  IM, Reed  JL, Giedinghagen  AM, Lewis  CB, Garwood  SK.  Disordered eating, food insecurity, and weight status among transgender and gender nonbinary youth and young adults: a cross-sectional study using a nutrition screening protocol.  LGBT Health. 2021;8(5):359–366.Google ScholarCrossref
Bishop  A, Overcash  F, McGuire  J, Reicks  M.  Diet and physical activity behaviors among adolescent transgender students: school survey results.  J Adolesc Health. 2020;66(4):484–490.Google ScholarCrossref
 Causes of obesity.  Centers for Disease Control and Prevention. Updated March 21, 2022. Accessed July 5, 2022. https://www.cdc.gov/obesity/basics/causes.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fobesity%2Fadult%2Fcauses.html
Klaver  M, Dekker  MJHJ, de Mutsert  R, Twisk  JWR, den Heijer  M.  Cross-sex hormone therapy in transgender persons affects total body weight, body fat and lean body mass: a meta-analysis.  Andrologia. 2017;49(5):1–11.Google ScholarCrossref
Linsenmeyer  W, Drallmeier  T, Thomure  M.  Towards gender-affirming nutrition assessment: a case series of adult transgender men with distinct nutrition considerations.  Nutr J. 2020;19(1):1–18.Google Scholar
Conron  KJ, O'Neill  KK.  Food insufficiency among transgender adults during the COVID-19 pandemic.  Williams Institute, UCLA School of Law; 2022. Accessed July 5, 2022. https://williamsinstitute.law.ucla.edu/wp-content/uploads/Trans-Food-Insufficiency-Update-Apr-2022.pdf
Russomano  J, Patterson  JG, Jabson  JM.  Food insecurity among transgender and gender nonconforming individuals in the Southeast United States: a qualitative study.  Transgend Health. 2019;4(1):89–99.Google Scholar
Diemer  EW, Grant  JD, Munn-Chernoff  MA, Patterson  DA, Duncan  AE.  Gender identity, sexual orientation, and eating-related pathology in a national sample of college students.  J Adolesc Health. 2015;57(2):144–149.Google Scholar
Parker  LL, Harriger  JA.  Eating disorders and disordered eating behaviors in the LGBT population: a review of the literature.  J Eat Disord. 2020;8:1–20.Google Scholar
Simone  M, Hazzard  VM, Askew  AJ, Tebbe  EA, Lipson  SK, Pisetsky  EM.  Variability in eating disorder risk and diagnosis in transgender and gender diverse college students.  Ann Epidemiol. 2022;70:53–60.Google Scholar
Hernandez  DC, Reesor  LM, Murillo  R.  Food insecurity and adult overweight/obesity: gender and race/ethnic disparities.  Appetite. 2017;117:373–378.Google Scholar
Barnes  RD, Blomquist  KK, Grilo  CM.  Exploring pretreatment weight trajectories in obese patients with binge eating disorder.  Compr Psychiatry. 2011;52(3):312–318.Google Scholar
Appolinario  JC, Sichieri  R, Lopes  CS,  et al.  Correlates and impact of DSM-5 binge eating disorder, bulimia nervosa and recurrent binge eating: a representative population survey in a middle-income country.  Soc Psychiatry Psychiatr Epidemiol. 2022;57(7):1491–1503.Google Scholar
Jones  BA, Haycraft  E, Bouman  WP, Arcelus  J.  The levels and predictors of physical activity engagement within the treatment-seeking transgender population: a matched control study.  J Phys Act Health. 2018;15(2):99–107.Google Scholar
Lucassen  MFG, Guntupalli  AM, Clark  T,  et al.  Body size and weight, and the nutrition and activity behaviours of sexual and gender minority youth: findings and implications from New Zealand.  Public Health Nutr. 2019;22(13):2346–2356.Google Scholar
Muchicko  MM, Lepp  A, Barkley  JE.  Peer victimization, social support and leisure-time physical activity in transgender and cisgender individuals.  Leisure. 2014;38(3-4):295–308.Google ScholarCrossref
 About adult BMI.  Centers for Disease Control and Prevention. Reviewed June 3 , 2022. Accessed June 30, 2022. https://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/index.html#Used
Elling-Machartzi  A.  Extraordinary body-self narratives: sport and physical activity in the lives of transgender people.  Leisure Stud. 2015;36(2):256–268.Google ScholarCrossref
Hargie  ODW, Mitchell  DH, Somerville  IJA.  “People have a knack of making you feel excluded if they catch on to your difference”: transgender experiences of exclusion in sport.  Int Rev Sociol Sport. 2017;52(2):223–239.Google ScholarCrossref
Jones  BA, Arcelus  J, Bouman  WP, Haycraft  E.  Barriers and facilitators of physical activity and sport participation among young transgender adults who are medically transitioning.  Int J Transgend. 2017;18(2):227–238.Google ScholarCrossref
López-Cañada  E, Devís-Devís  J, Pereira-García  S, Pérez-Samaniego  V.  Socio-ecological analysis of trans people's participation in physical activity and sport.  Int Rev Sociol Sport. 2021;56(1):62–80.Google ScholarCrossref
Pérez-Samaniego  V, Fuentes-Miguel  J, Pereira-García  S, López-Cañada  E, Devís-Devís  E.  Experiences of trans persons in physical activity and sport: a qualitative meta-synthesis.  Sport Manage Rev. 2019;22(4):439–451.Google Scholar
Burkhauser  RV, Cawley  J.  Beyond BMI: the value of more accurate measures of fatness and obesity in social science research.  J Health Econ. 2008;27(2):519–529.Google Scholar
Linsenmeyer  W, Coffey  M.  “Going from invisible to visible”: challenging the “normal” ranges, cut-offs and labels used to describe the sizes and shapes of transgender and gender diverse bodies.  In: Joy  P, Aston  M, eds.  Queering Dietetics. Routledge. Forthcoming 2022.Google Scholar
Martinson  TG, Ramachandran  S, Lindner  R, Reisman  T, Safer  JD.  Higher body mass index is a significant barrier to gender-confirmation surgery for transgender and non-binary individuals.  Endocr Pract. 2020;26(1):6–15.Google Scholar
Deutsch  MB, ed.  Guidelines for the Primary and Gender-Affirming Care of Transgender and Gender Nonbinary People. 2nd ed. University of California San Francisco Gender Affirming Health Program; 2016. Accessed July 5, 2022. https://transcare.ucsf.edu/guidelines
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Credit Designation Statement: The American Medical Association designates this Journal-based CME activity activity for a maximum of 1.00  AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:

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