Overview

Overlake Medical Clinics Metabolic + Bariatric Services

Our dedicated team provides comprehensive, personalized treatment to help you reach your weight-loss goals. Whether through our state-of-the-art metabolic and bariatric surgery options or our medical weight management program, Overlake has the tools to help you reach your ideal weight.

Metabolic + Bariatric Surgery

Obesity is the second leading cause of preventable death in the United States, following smoking. However, less than five percent of people with severe obesity (80 to 100 pounds or more overweight) are able to lose this weight through exercise and dieting. When these efforts have failed, you and your doctor should discuss weight loss (bariatric) surgery, and whether it is right for you.

Medical Weight Management

More than two-thirds of American adults are considered overweight or obese. Weight may be the result of many factors, including genetics, lifestyle choices, metabolic conditions and medications. 

Obesity is a complex disease that requires medical management from a care team with skill, experience and compassion.

Our program for medical weight management is about improving your health and well-being, not just focusing on the scale. We can help you navigate the often confusing, conflicting data and misinformation about diet. Our comprehensive, personalized approach is based on scientific research in weight management and years of experience. Our program includes:

  • Physical exam
  • Review of medical history and available lab
  • Monthly follow-up with a multidisciplinary team, which includes: a weigh in, review of progress and challenges, plan adaptations as needed, addressing challenges together, support and encouragement, and medications as needed.

Support Groups for Surgery Patients

Support Groups

Our support group meetings are moderated by health care professionals and are an excellent resource for information. You’ll find people who have similar wellness goals, who want to celebrate your successes and who support you in challenging times. This is a drop-in support group no registration required.

Overlake Medical Center
PACCAR Education Center
1035 116th Avenue NE
Bellevue, WA 98004

For more information, call 425.467.3957.

Click here for 2018 support group's times and dates.

In the News

Overlake Bariatric Surgeon Thien Nguyen, MD, with Patient Chris Zito on KING5's Facebook Live | KING5 NEWS

Watch the KING5 Facebook Live video on Zito's journey.


Bariatric surgery addresses obesity and is also a promising treatment for diabetes | Healthy Outlook

Obesity is a leading cause of preventable death in the United States, but fewer than five percent of people with severe obesity are able to shed their excess weight with diet and exercise. Metabolic and bariatric surgery — which can improve sugar metabolism and cause dramatic weight loss — offers hope.

Overlake Medical Center offers leading-edge surgery within a comprehensive program that gives patients the tools and support they need. As a result, Overlake patients experience fewer problems — such as infections, readmissions and lengthy hospital stays — than the national rates.

Read more.


Husband and wife undergo bypass surgery at Overlake Medical Center | Q13 FOX NEWS

Kelly and Jason Guffin each lost 250 pounds in a single year. See their amazing transformation.

Watch the Q13 Fox News report on the Guffin’s experience.


Bellevue physician sees weight-loss surgery as life-saving effort | Bellevue Reporter

At the age of 36, Dr. Thien Nguyen has already lived a full life and overcome challenging obstacles. Today, the Medical Director for the Weight Loss Surgery Program at Overlake Hospital Medical Center in Bellevue uses his past experiences to teach his patients about perseverance and quality of life.

Read more.


Robotic Weight Loss Surgery: Thanks to advanced technology, one overweight family finally shed excess pounds | Healthy Outlook

In May of this year, three members of an Auburn family — all more than 300 pounds in weight — changed their lives.

That’s when Kelly and her husband, Jason, underwent robotic weight loss (bariatric) surgery at Overlake Medical Center, as did the oldest of the couple’s four children, Cory.

Read more.

Map + Directions

Map + Directions (PDF)

Meet Our Team

Carmela Pontillo, RN, MSN, CBN — Bariatric Program Manager

Carmela has been working at Overlake since 2011 as the bariatric program manager and in the field of bariatric surgery since 2004. She was certified by the ASMBS as a Bariatric Nurse in 2008, and holds a degree in psychology and a master’s degree in nursing from McGill University in Montreal, Canada.

Although she has worked as a registered nurse for more than 30 years in many different areas, Carmela feels that working in metabolic and bariatric surgery has been by far the most rewarding. She considers it a great privilege to be granted the opportunity to share in our patients’ remarkable journeys towards health and wellness

Shiree Harsh — Clinic Supervisor

Shiree has been with the clinic since 2011. For her, being able to share in the journey of the patients as they work toward their goal of weight loss is most rewarding. Shiree believes it is important for patients to feel confident that she and the rest of Overlake’s staff are committed to working just as hard as the patient to make sure that their goal of weight loss and a healthier lifestyle is reached. The relationship created between patient, staff and physician during this process is a very special one, where everyone shares in the journey and everyone celebrates together each step toward a healthier life style.

Carrie Tollefson — Outpatient and Clinical Dietician

Carrie has worked for Overlake Medical Center since 2006 and with the bariatric program since 2010. She enjoys being part of bariatric patients’ journey to make significant changes in their lifestyle, eating and fitness habits. It is exciting for her to see their motivation and enthusiasm as they transform their way to better health. She is inspired by patients’ courage and dedication. Carrie co-facilitates the weight loss surgery support group with Randy Brandeis and Carmela Pontillo. Together with the patients, all three clinic staff share special moments together where they laugh, cry, grow and change. Carrie is very proud of the patients in this group.

Randy Brandeis, MSW, CSW — Clinical Social Worker

Randy co-facilitates the bimonthly support groups at Overlake, provides psychological evaluations for pre-surgery patients and sees individuals in his clinic practice. Randy has worked in multidisciplinary settings for 25 years and is committed to the Overlake concept that the best patient outcomes are the result of diverse professional disciplines working together.

Randy Brandeis is a board-certified clinical social worker who received his Masters degree in 1976 from the University of Illinois Jane Addams School of Social Work. Randy has worked since 1987 on the cognitive and behavioral treatment of obesity and other chronic medical conditions. He has worked with bariatric surgery patients since 2006.

Patient Forms: Initial Consultation Forms

Patient Forms: Pre-Op Forms

Surgical Options

Am I Candidate?

National Institutes of Health Guidelines for Bariatric Surgery
  • Body Mass Index (BMI) of 40 or greater
  • Body Mass Index (BMI) of greater than 35 with an obesity related health problem
  • Dietary attempts at weight control have been ineffective
  • Psychological stability
  • Knowledgeable about the operation (risks, benefits, long-term consequences)
  • Motivated
  • Existing medical problems do not preclude likely survival from surgery
Body Mass Index (BMI)

Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to both adult men and women. BMI does not differentiate between body fat and muscle mass. Therefore, body builders and people who have a lot of muscle bulk will have a high BMI but are not overweight or obese.

Fat predominantly distributed around the waist is also a risk factor for health complications such as cardiovascular disease and Type 2 diabetes. Fat predominantly deposited around the hips and buttocks doesn’t have this same risk.

BMI Calculator

BMI Calculator

Body mass index (BMI) is a person's weight in kilograms divided by the square of height in meters. According to the Centers for Disease Control and Prevention, "BMI does not measure body fat directly, but research shows that BMI is moderately correlated with more direct measures of body fat obtained from skinfold thickness measurements, bioelectrical impedance, densitometry (underwater weighing), dual energy X-ray absorptiometry (DEXA) and other methods. Furthermore, BMI appears to be as strongly correlated with various metabolic and disease outcome as are these more direct measures of body fatness.  In general, BMI is an inexpensive and easy-to-perform method of screening for weight category, for example underweight, normal or healthy weight, overweight, and obesity."

Visit the Centers for Disease Control and Prevention site to calculator your BMI.

Sleeve Gastrectomy

Sleeve Gastrectomy

The Sleeve Gastrectomy has become the most commonly performed bariatric surgery in the U.S. With this procedure, two-thirds of the stomach is removed using a stapling device. The new stomach is roughly the size of a banana, capable of holding approximately 150 mL. There is no rerouting of the gastrointestinal tract in this procedure.

Roux-en-Y Gastric Bypass

Roux-en-Y Gastric Bypass

The Roux en Y Gastric Bypass is considered the gold standard bariatric procedure. In this procedure, a small stomach pouch is created from the stomach. The new stomach pouch is capable of holding approximately 15 to 30 mL. Although the old remaining stomach no longer stores food, it continues to function and secrete digestive juices. The small intestine is divided into two sections. The lower section (Roux limb) is connected to the newly created stomach pouch. The upper section of the intestine (Biliopancreatic limb) is connected further downstream on the small intestine.

Robotic da Vinci® Bariatric Surgery

Robotic da Vinci® Bariatric Surgery

Overlake Medical Center first established its robotic surgery program in 2010. Since then, it has become a regional leader in the field and now offers robotic assisted procedures in urology, gynecology, general surgery and bariatric surgery.

Thien K. Nguyen, MD, performs robotic surgery.

Thien K. Nguyen, MD, performs robotic surgery

Visit the da Vinci website

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