While an important screening tool, BMI is not the only factor that determines whether you qualify for bariatric surgery. It is possible to have weight loss surgery even if you do not meet traditional BMI criteria.
Other considerations, such as obesity related comorbidities, have always been part of a bariatric evaluation. And in more recent years, the suggested BMI threshold itself has been lowered, further expanding eligibility criteria.
In this article, the expert bariatric surgical team at The Surgical Clinic in Middle TN explains what bariatric surgeons look for beyond BMI and how modern evidence-based standards are making it possible for more patients to qualify for bariatric surgery.
What is BMI and Other Terms to Understand
There are words you might not fully understand that will be used throughout this BMI criteria guide for bariatric surgery. Here are their simple definitions.
- Body Mass Index (BMI): BMI is a simple height and weight calculation that has been used for decades to estimate health risk. It does not measure body fat directly, but it is still the starting point for determining weight loss surgery eligibility.
- Comorbidities: These are health conditions that often occur with obesity. Examples include type 2 diabetes, high blood pressure, sleep apnea, high cholesterol, and joint problems.
- Metabolic Health: This refers to how well your body manages blood sugar, insulin, cholesterol, liver function, and inflammation. Even if your BMI is lower, metabolic issues can increase health risks.
- Bariatric Surgery: This is the medical term for all weight loss procedures like gastric bypass or sleeve gastrectomy. These surgeries change the size or function of the stomach to support long-term weight loss and metabolic improvement.
- Medical Weight Management: A non-surgical option that includes prescription medications, nutrition guidance, and ongoing medical supervision.
What are the Requirements for Bariatric Surgery in 2025?
To be eligible for bariatric surgery, such as a vertical sleeve gastrectomy or gastric bypass, there are BMI requirements. However, BMI is not the only deciding factor. Surgeons also consider your metabolic health and obesity related comorbidities.
Additionally, in 2025, BMI thresholds are lower than they once were. Decades of research, reflecting significant advancements in modern bariatric surgery and a better understanding of obesity as a complex chronic disease, resulted in new guidelines being established a few years ago that lower BMI ranges and broaden patient eligibility.
While some doctors and insurance companies still reference older standards in determining weight loss surgery eligibility, many bariatric surgeons follow the newer weight loss surgery guidelines established in 2022, rather than the outdated standards set over 30 years ago by the National Institutes of Health, which set the original BMI thresholds of 40 or 35 with a qualifying health condition.
Outdated Bariatric Surgery Requirements
In 1991, the National Institutes of Health established a BMI-based framework for bariatric surgery qualification. According to those recommendations, bariatric surgery was only advised for patients with:
- A BMI of 40 or higher
- Or a BMI of 35 or higher with at least one significant obesity related health condition, such as type 2 diabetes, sleep apnea, high blood pressure, or debilitating joint disease.
For more than thirty years, these standards shaped how many bariatric surgeons evaluated candidacy and whether or not an insurance company would cover a weight loss surgery. However, they were created under very different surgical conditions and clinical understandings than we have today.
Back then, bariatric surgery was more invasive and carried higher risks. Therefore, the NIH deemed it necessary to establish strict BMI thresholds to ensure that the potential benefits clearly outweighed the surgical risk.
Additionally, at that time, the medical community lacked the long-term clinical research that is now available, which demonstrates the benefits of earlier intervention.
While well-intentioned, these rigid cutoffs left many patients who could have benefited from bariatric surgery as a weight loss solution unqualified because they did not meet what the NIH considered a high enough level of obesity.
That’s not to say BMI isn’t an important criterion for weight loss surgery. BMI helps classify obesity-related health risks and provides a measurable starting point for determining who may benefit from metabolic and bariatric interventions.
It is often necessary to lower your BMI before surgery. However, we now know that BMI by itself does not always reflect a patient’s metabolic risk and does not always show how excess weight is affecting overall health.
This deeper understanding, combined with improved surgical safety, led major metabolic health organizations to update the guidelines and adjust BMI thresholds to include more patients who may benefit from bariatric surgery.
Updated Bariatric Surgery Guidelines
The NIH Consensus Development Program, which created the 1991 BMI recommendations for weight-loss surgery, no longer issues official statements or clinical practice guidelines for obesity treatment. As a result, the responsibility shifted to professional medical societies specializing in obesity and metabolic diseases.
Two of the world’s leading authorities, the American Society for Metabolic and Bariatric Surgery and the International Federation for the Surgery of Obesity and Metabolic Disorders, released new evidence-based guidelines in 2022 that reflect current scientific understanding of obesity and modern bariatric surgery practices.
The updated guidelines state a person should qualify for bariatric surgery if they meet the following criteria:
- BMI of 35 or higher: Recommended for bariatric surgery, even without other health conditions.
- BMI of 30 to 34.9: Recommended for bariatric surgery if a patient has a related metabolic disease, such as type 2 diabetes.
- BMI of 30 or higher: Should be considered for bariatric surgery if the patient has been unable to achieve meaningful or lasting weight loss through non-surgical methods.
The agencies developed these recommendations based on three decades of data showing the safety and long-term effectiveness of modern bariatric procedures. This updated approach also takes into consideration modern data, which shows that earlier treatment can reduce long-term health risks, prevent further metabolic damage, and improve overall outcomes.
While many bariatric surgeons now follow these updated guidelines, it’s important to note that some doctors and many insurance companies still reference the older NIH standards. This can lead to situations where a patient qualifies medically under current guidelines but still faces being told they do not meet BMI criteria.
Why Some Providers and Insurance Plans Still Use the Old BMI Guidelines
It is possible to qualify medically under the updated bariatric surgery guidelines, yet still be told you do not meet the insurance requirements for coverage.
Although the 2022 guidelines reflect the most current medical evidence, not all providers or insurance companies have adopted them. Some insurance plans still rely on the older 1991 NIH criteria when deciding what they will cover, and some medical practices continue to reference those same standards.
Professional societies, such as the ASMBS, are actively working to advocate for change, urging insurers and policymakers to adopt the current, evidence-based recommendations to ensure patients have access to the most effective treatments for obesity and related conditions.
In 2025, Bariatric Surgeons Consider More Than BMI Criteria
BMI can be a helpful screening tool, but it is not a perfect measure of health. It is a simple height and weight calculation that does not distinguish between fat and muscle, and it does not account for how your weight affects daily function or metabolic health.
Many bariatric surgeons now recognize that a true evaluation extends far beyond a single number. They may assess multiple factors that offer far more insight than BMI alone, such as:
- Metabolic Health: You may not have type 2 diabetes, but you might be insulin-resistant or pre-diabetic. You may have high cholesterol or fatty liver disease. These metabolic issues are early warning signs that your weight is affecting your health on a deeper level and can be a compelling reason to intervene sooner.
- Serious Comorbidities: Obesity related health conditions have always mattered, but surgeons now evaluate them more closely. Conditions such as severe sleep apnea, significant joint pain, hypertension, and GERD can reduce your quality of life and increase long-term risks, even when BMI is below 35.
- Quality of Life: Feeling exhausted when playing with your children or grandchildren, avoiding activities because of chronic pain, or struggling emotionally because of weight-related challenges are meaningful indicators of health impact. A lower BMI does not make these issues insignificant, and should be part of your overall assessment.
What If I Still Don’t Qualify for Weight-Loss Surgery? Exploring Non-Surgical Weight Loss Options
If your bariatric surgeon does not feel that surgery is the most appropriate choice or your insurance company has denied coverage for weight loss surgery, you still have effective and medically supported weight loss options, including non-surgical procedures and medically supervised weight loss programs that include prescription medications.
Non-Surgical and Minimally Invasive Procedures
There are non-surgical and minimally invasive procedures that can be highly effective for individuals who may not qualify for weight loss surgery or who are not ready to take that step.
These procedures offer an alternative to traditional surgery for individuals with obesity or weight-related health problems, with benefits like no external incisions, faster recovery, and fewer complications.
Some of the most common and effective alternatives include:
- Endoscopic Sleeve Gastroplasty (ESG): A minimally invasive incisionless procedure where a doctor uses an endoscope (a thin, flexible tube with a camera) to place sutures inside the stomach, reducing its size by about seventy to eighty percent. This limits the amount of food the stomach can hold, which helps you feel full faster.
- Intragastric Balloon: A minimally invasive, incisionless technique where a soft balloon, or sometimes two, is endoscopically placed in the stomach. The balloon takes up space in the stomach and limits how much you can comfortably eat. It is usually removed after about six months. This approach helps initiate significant early weight loss and supports the development of lasting nutrition and exercise habits.
Aspiration therapy is another minimally invasive weight loss solution you might hear about when searching for bariatric surgery alternatives. However, it is not commonly used and requires a small incision in the abdomen. Unlike ESG and intragastric balloons that physically alter the stomach’s size or capacity to restrict intake, aspiration therapy works by removing calories after a meal and can drain up to about 30 percent of ingested calories before the body digests them.
Medically Supervised Weight Loss Programs
If surgery is not recommended, you are not ready for an operation, or you do not want to explore endoscopic weight loss procedures, many bariatric centers offer comprehensive weight loss programs designed for individuals who need to lose a significant amount of weight.
These programs go beyond providing a simple diet and exercise plan and often include:
- Prescription Weight Loss Medications: Weight loss drugs have advanced significantly over the last few years. There are now safer and more effective FDA-approved GLP-1 agonists, such as semaglutide (available as Wegovy for weight management and Ozempic for type 2 diabetes) and tirzepatide (available as Zepbound for weight management), that are used for chronic weight management. Several newer GLP-1-based medications are also in development.
- Personalized Nutrition and Exercise Plans: The foundation for weight loss has always been, and will always be, living a healthy lifestyle. Registered dietitians, exercise specialists, and bariatric-trained clinicians can create a personalized nutrition and exercise plan tailored to your body, schedule, and long-term goals.
- Behavioral and Mental Health Support: Emotional eating, stress, past trauma, and mood disorders can all influence weight and overall health. Many medically supervised programs include behavioral therapy or mental health support to help you build long-lasting habits and address the emotional side of weight management.
In addition to being used as an alternative to weight loss surgery, medical weight management programs that incorporate GLP-1S are also commonly used to help patients reach a BMI that qualifies them for bariatric surgery, when weight loss is necessary to reduce surgical risk, or after bariatric surgery when patients experience insufficient weight loss or weight regain.
To learn more, read “Can You Take Ozempic if You Had Weight Loss Surgery?”
Your Next Step: A Conversation with a Bariatric Specialist
If you have read information suggesting that you do not meet the BMI criteria for weight loss surgery, have been told in the past that you are not a candidate because of your BMI, or your insurance has denied coverage, it is possible that with the updated BMI guidelines and a more comprehensive evaluation, your situation may now be different.
The only way to know if you qualify for weight loss surgery today is to book a consultation with a bariatric surgeon near you.
A bariatric surgery consultation is a conversation, not a commitment. It provides you with the opportunity to discuss your goals, challenges, and past attempts to lose weight. It also allows a bariatric surgeon to review your full health picture and explain every option that may be appropriate for you, including bariatric surgery, endoscopic procedures, or a medically supervised weight loss program.
If you are looking for a bariatric surgeon in Nashville or the greater Middle Tennessee area, at The Surgical Clinic, our team takes a personalized and evidence-based approach to determining whether weight loss surgery is the right choice for you. We guide our patients using the most current medical standards, with clarity, compassion, and practical next steps.
Your health journey is personal. Contact our bariatric team today to schedule a consultation, and let us help you determine your next step together.
Other Frequently Asked Questions About Bariatric Surgery and BMI Requirements
Can I get bariatric surgery with a BMI of 30?
Patients with a BMI of 30 or higher may qualify under the 2022 ASMBS and IFSO guidelines, especially if they have a metabolic condition like type 2 diabetes or have been unable to lose weight through non-surgical methods.
This does not guarantee that a surgeon will recommend surgery or that insurance will cover it. If you were previously told you did not qualify, a comprehensive evaluation or a second opinion with an experienced bariatric surgeon is the best next step.
How do I know if I’m a candidate for endoscopic procedures instead of surgery?
Endoscopic procedures like ESG and intragastric balloons are typically recommended for patients with a BMI between 30 and 40 who may not yet need or want traditional bariatric surgery. These procedures are also options for patients who wish to try a less invasive approach first.
Will I be required to try other weight loss methods before I can have surgery?
Many insurance companies require documentation of supervised weight loss attempts, but requirements vary widely.
Is bariatric surgery safe for people with a lower BMI?
Whether or not bariatric surgery is safe for individuals with a lower BMI depends on how one defines ‘low’. For bariatric surgery, a lower BMI typically indicates a value between 30 and 35. Research suggests that patients within this range often achieve excellent outcomes and may experience fewer complications compared to patients with a very high BMI. Working with a board-certified bariatric surgeon is the best way to determine the safest option for your individual needs.
For more FAQ and answers from bariatric experts, click here.