Weight Loss Surgery for Low BMI Patients (BMI 30-35)

In previous posts we have discussed why weight loss surgery works (it changes the body weight set-point!) and why diets don’t work (they don’t change the body weight set-point), and we have shown that weight loss surgery is safe.

If all this is true why is it that patients are often told they have to be at least 75-100 pounds overweight (body mass index (BMI) >35) to have bariatric surgery?

Mild obesity, also know as class 1 obesity, or low BMI obesity (BMI 30-35, typically 50-75 pounds over ideal weight), can lead to serious medical problems, hinder quality of life, and shorten lifespan. Shouldn’t weight loss surgery, the only obesity treatment shown to be effective long-term, be attainable for the millions of people with low BMI obesity? We think so!

NIH Guidelines for Weight Loss Surgery

The NIH guidelines for weight loss surgery, which insurance companies follow, were proposed more than 20 years ago and are now outdated. Those guidelines state that bariatric surgery can be considered for patients who have: a BMI > 40, or a BMI >35 with major weight related medical problems such as diabetes.

Since those guidelines were proposed in 1991, new bariatric procedures have been introduced (LAP-BAND®, sleeve gastrectomy), the laparoscopic approach has replaced the open approach, bariatric surgery outcomes have greatly improved, and we have a better understanding of the significant danger of obesity.

Weight Loss Surgery for Low BMI Patients (BMI 30-35) is Reasonable

The American Society for Metabolic and Bariatric Surgery (ASMBS) recently published a low BMI position statement on the use of bariatric surgery for low BMI patients (BMI 30-35). BMI 30-35 corresponds to roughly 50-75 pounds overweight.

The summary and recommendations from the ASMBS position statement on weight loss surgery for low BMI patients are as follows:

  • Class I obesity (BMI 30-35) is a well-defined disease that causes or exacerbates multiple other diseases, decreases the duration of life, and decreases the quality of life. The patient with Class I obesity should be recognized as deserving treatment for this disease.
  • Current options of non-surgical treatment for Class I obesity are not generally effective in achieving a substantial and durable weight reduction.
  • For patients with BMI 30-35 who do not achieve substantial and durable weight and comorbidity improvement with non-surgical methods, bariatric surgery should be an available option for suitable individuals. The existing cut-off of BMI which excludes those with Class 1 obesity was established arbitrarily nearly 20 years ago. There is no current justification on grounds of evidence of clinical effectiveness, cost-effectiveness, ethics or equity that this group should be excluded from life-saving treatment.
  • Gastric banding, sleeve gastrectomy, and gastric bypass have been shown in randomized, controlled trials to be safe and effective treatment for patients with BMI 30-35 in the short and medium term.

Read the entire ASMBS position statement on bariatric surgery for low BMI patients: Bariatric Surgery in Class 1 Obesity (BMI 30-35)

The International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) has also endorsed weight loss surgery in a position statement for low BMI patients (BMI 30-35).

Recent Published Studies on Weight Loss Surgery for Low BMI Patients

Results of Laparoscopic Sleeve Gastrectomy in 541 Patients with Low BMI (30-35)
This is a large study (541 patients) that shows excellent average weight loss results (78% excess weight loss at 1 year) and low complication rates (leak 0%, bleeding 1.2%) in low BMI patients who underwent sleeve gastrectomy surgery.*
Bariatric Surgery in Moderately Obese Patients
This is an older, smaller study (25 patients) that shows good outcomes in low BMI patients who underwent either gastric bypass surgery or gastric sleeve surgery.*
Gastric Bypass Surgery in Patients with Diabetes and Only Mild Obesity
This study (66 patients) showed that diabetes went into remission in 88% of low BMI patients with diabetes who underwent gastric bypass surgery.*
Sleeve Gastrectomy for Patients with Class 1 Obesity (BMI 30-35)
This is an early study (2009) that showed good short term outcomes in 23 low BMI patients who underwent sleeve gastrectomy surgery.*
Diabetes in Patients with BMI 30-35: Sleeve Gastrectomy vs. Medical Treatment
This is a small study that showed 89% remission of diabetes in 9 diabetic low BMI patients who underwent gastric sleeve surgery.*

Our Experience with Weight Loss Surgery for Low BMI Patients

We have been performing weight loss surgery for low BMI patients since 2003. We have operated on 260 low BMI patients – 19 gastric bypass, 166 gastric banding (none since 2013), and 75 sleeve gastrectomy. Currently we mostly do sleeve gastrectomy for low BMI patients, but we also occasionally do gastric bypass for low BMI patients with diabetes.

Our experience with sleeve gastrectomy for low BMI patients is similar to the experience reported in the first study quoted above – Results of Laparoscopic Sleeve Gastrectomy in 541 Patients with Low BMI (30-35). Our weight loss results have been excellent in our low BMI gastric sleeve patients (average 87% EWL at 1 year postop, 82% EWL at 2 years postop, and 78% EWL at 3 years postop), and our complication rates have also been low (leak rate 0%, bleeding 0%).*

* Patient outcomes vary after weight loss surgery. Patients can do better or worse than the averages reported above.

Learn More

Learn more about Orange County bariatric surgeon Dr. Oliak and his Orange County weight loss surgery program.


Contact Us

If you are interested in learning more about weight loss surgery and our program, call our office at (714) 582-2530, or send us your contact information using the form below, and we will contact you.

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