# Understanding Weight-Loss Surgery Worldwide: The 2019 IFSO Global Registry Report Explained This report analyzes data from 833,687 bariatric (weight-loss) and metabolic surgeries performed across 61 countries and submitted to the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) Global Registry. The key finding: one year after surgery, patients lost an average of 31.1% of their body weight, and 64.2% of patients taking diabetes medication no longer needed it, with similar dramatic improvements in high blood pressure and cholesterol. The report also reveals significant global variations in who gets surgery, which procedures are used, and the burden of obesity-related diseases, highlighting both the power and the limitations of real-world surgical data. # Understanding Weight-Loss Surgery Worldwide: The 2019 IFSO Global Registry Report Explained ## Table of Contents - Key Points - Why This Registry Matters - The Scope of the Registry: 833,687 Operations - How the Research Was Conducted - Patient Demographics: Age, Gender, and BMI - Obesity-Related Diseases Before Surgery - Types of Surgery Performed - Immediate Outcomes: Hospital Stay and Recovery - One-Year Results: Weight Loss and Disease Remission - What This Means for Patients - What This Study Could Not Show - Recommendations for Patients and Providers - Frequently Asked Questions - Source Information ## Key Points - The 2019 IFSO Global Registry report analyzed 833,687 bariatric surgeries from 61 countries. - One year after surgery, patients lost 31.1% of total body weight; 64.2% stopped diabetes medication. - Sleeve gastrectomy was the most common procedure (47%), with 99.1% performed laparoscopically. - Typical patients were 43 years old, had a BMI of 44.3, and were female (77.1%). - Only 30.1% of patients had follow-up data, so one-year results may not represent everyone. ## Why This Registry Matters Obesity is a global health crisis with devastating consequences, and surgical treatment — known as bariatric or metabolic surgery — is one of the most powerful tools available to fight it. But until recently, there was no comprehensive way to understand how this surgery is being used worldwide, who is receiving it, and how well it actually works in everyday practice (as opposed to controlled clinical trials). The IFSO Global Registry was created to fill that gap. It is a collaborative project run by the International Federation for the Surgery of Obesity and Metabolic Disorders, in partnership with Dendrite Clinical Systems, a UK-based company that builds and maintains the web-based registry. This Fifth Report, published in September 2019, represents the largest database of bariatric/metabolic surgery ever assembled. As IFSO President Almino Ramos wrote in the report's preface: "Real and true data is the only way for convincing our peer specialties, governments, insurers, health care companies and the general community about the benefits of bariatric/metabolic surgery." He emphasized that the ultimate goal is simple: **"improve the outcomes offered to our patients."** ## The Scope of the Registry: 833,687 Operations The numbers in this report are staggering. A total of **833,687 bariatric operation records** were submitted from **61 countries**, representing some **14.6 million individual baseline data-items**. Well over **1,000 hospitals** contributed data, either directly or through their national registry submissions. The volume of data nearly doubled compared to the previous year's report. The number of records submitted per country ranged from a single entry from one center, to over **335,000 records submitted for the very first time by the national registry from the United States of America** — by far the largest tranche of data from a single country, roughly four times larger than any other contributor. This means that any headline figures in the report are heavily influenced by data from the USA. The report also notes that most records fell in the period **2012–2019 (86.3%)**, with **594,235 operations (71.3%) dated in the calendar years 2015–2018**. ## How the Research Was Conducted The registry uses a standardized dataset containing **41 variables**: 28 in the baseline record (collected before surgery) and 13 in the follow-up section (collected after surgery). Data were submitted by national registries, regional systems, and individual hospitals from around the world. Overall, **78.3% of the baseline records were more than 70% complete** for operations dated 2015–2018, indicating generally good data quality. The report used the same dataset as the Fourth Report (2018) to ensure consistency across editions. The analysis was organized according to the IFSO Chapter to which each contributing country belongs — these are regional groupings: Asia-Pacific (APC), European (EC), Latin American (LAC), Middle East/North Africa/Cyprus (MENAC), and North American (NAC). Notably, the Fifth Report includes a large tranche of data from North America for the first time. The researchers deliberately did **not** perform statistical comparisons between countries or attempt to analyze complications or mortality data, because the data have not been validated for those purposes. As the introduction states, they "steered well clear of attempting to make statistical comparisons based on these unvalidated data." ## Patient Demographics: Age, Gender, and BMI ### Gender Inequality in Access to Surgery Overall, **77.1% of patients were female** (95% CI: 76.9–77.2%). But this varied enormously by country. The proportion of female patients ranged from **43.3% in Belgium** to **93.1% in Guadeloupe**. This wide variation suggests significant differences in access to surgery for men across different health systems, a finding the authors flag as an important issue. ### Age at Time of Surgery The median age of patients at the time of primary surgery was **43.0 years** (inter-quartile range: 34.0–52.0 years). In other words, half of all patients were between 34 and 52 years old. ### Body Mass Index (BMI) Body mass index (BMI) is a measure of body fat based on height and weight. The median BMI before surgery was **44.3 kg/m²** (inter-quartile range: 40.4–49.8 kg/m²). For context, a BMI of 30 or above is considered obese, and 40 or above is classified as severe (or "morbid") obesity. So the typical patient in this registry had severe obesity. There was a very wide variation in BMI between countries. The lowest median pre-surgery BMI was **36.4 kg/m² in Chile**, and the highest was **52.9 kg/m² in Bulgaria**. This may reflect differences in referral criteria, health system policies, or the underlying obesity burden in each population. ## Obesity-Related Diseases Before Surgery The registry collected detailed information on obesity-related conditions (comorbidities) present before surgery. The following figures represent patients who were on medication for these conditions or had the diagnosis, based on countries contributing more than 100 records: - **Type 2 diabetes:** 23.3% of patients were on medication (inter-country variation: 8.7–93.9%) - **Hypertension (high blood pressure):** 41.0% were on medication (inter-country variation: 15.5–90.4%) - **Depression:** 16.5% were on medication (inter-country variation: 0.2–77.4%) - **Musculoskeletal pain:** 12.0% were on medication (inter-country variation: 0.0–64.7%) - **Sleep apnea:** 18.9% had the condition (inter-country variation: 0.0–74.4%) - **Gastro-esophageal reflux disorder (GERD, chronic acid reflux):** 25.1% had the condition (inter-country variation: 0.0–54.8%) These wide variations (for example, from less than 1% to over 93% for diabetes medication use) likely reflect a combination of genuine population differences, differing diagnostic practices, and variations in how completely data were recorded in different countries. ## Types of Surgery Performed Bariatric surgery includes several different procedures. This report tracked the four most common ones, and found wide variation in practice around the world: - **Sleeve gastrectomy** (stomach reduction to a tube/sleeve shape): **391,423 procedures (47.0% of all records)** — the most common operation overall - **Roux-en-Y gastric bypass** (stomach pouch creation with intestinal rerouting): **294,530 procedures (35.3%)** - **Gastric banding** (an adjustable band placed around the stomach): **70,085 procedures (8.4%)** - **One anastomosis gastric bypass (OAGB/MGB, mini-gastric bypass):** **30,914 procedures (3.7%)** Some countries reported only sleeve gastrectomy — Australia (a multi-centre contributor), Guadeloupe, and Peru each reported **100% sleeve gastrectomy** (though Guadeloupe and Peru were each represented by a single hospital). At the other extreme, some countries reported almost 85% Roux-en-Y gastric bypass. The highest proportions of Roux-en-Y gastric bypass were in **Canada (84.3%), Colombia (80.7%), and Brazil (76.6%)**. One country reported almost all its operations as one anastomosis gastric bypass (OAGB/MGB). One of the most striking findings: **99.1% of all operations were performed laparoscopically** (minimally invasive, "keyhole" surgery), reflecting a major technological shift in how these procedures are delivered. ## Immediate Outcomes: Hospital Stay and Recovery The report examined how long patients stayed in hospital after surgery. Patterns were generally similar across most IFSO Chapters, with one exception: patients in the Asia-Pacific Chapter tended to stay a little longer in hospital. The authors note that the reasons are "not clear from the data, but are more likely to be driven by organisational issues than anything to do with the quality of surgery." Average (and median) hospital stays by procedure type were: - **Gastric banding:** average 1.0 days; median 1.0 days - **Sleeve gastrectomy:** average 1.9 days; median 2.0 days - **Roux-en-Y gastric bypass:** average 2.1 days; median 2.0 days - **One anastomosis gastric bypass (OAGB/MGB):** average 2.8 days; median 2.0 days These short hospital stays confirm that modern bariatric surgery is generally performed as a minimally invasive procedure with a quick recovery in the hospital setting. The longer average stay for OAGB/MGB (2.8 days vs. 2.0 median) suggests that some patients in that group required additional recovery time. ## One-Year Results: Weight Loss and Disease Remission The most important question for any patient considering bariatric surgery is: **Does it work?** The registry data provide a powerful answer, though with an important caveat about follow-up rates. For primary (first-time) operations performed in **2012–2017**, there were **559,256 operation records**. Of these, **168,580 had one or more follow-up records (30.1%)**, totaling **509,999 separate follow-up records**. This means about 70% of patients did not have follow-up data recorded — a significant limitation discussed below. Among patients with follow-up data, the results were striking: - **Average weight loss of 31.1%** of total body weight at one year after surgery - **64.2% of patients taking medication for type 2 diabetes no longer needed it** — and this was directly correlated with the amount of weight loss achieved - **45.4% of patients taking medication for hypertension no longer required it** - **51.8% of patients on cholesterol-lowering medication (for dyslipidemia) were able to stop it** Patients also saw improvement in other obesity-related conditions, including **sleep apnea** and **gastro-esophageal reflux disorder (GERD)**, though the extent of these improvements varied from one operation type to another. These findings align with the report's conclusion that "this Report demonstrates the profound positive treatment-effects of bariatric and metabolic surgery." ## Surgical Risk Stratification The report also examined the risk profile of patients undergoing surgery using the **Obesity Surgery Mortality Risk Score (OSMRS)**, a scoring system that helps predict the risk of death after bariatric surgery based on factors like age, BMI, blood pressure, and known risk conditions (such as previous blood clots, pulmonary embolism, and inability to walk). The distribution of risk scores varied widely by country. The countries with the **highest-risk patient populations** (combined OSMRS groups B & C, indicating elevated risk) were: - **Georgia: 88.1%** of patients in the higher-risk groups - **Hong Kong: 68.2%** - **Mexico: 57.7%** The countries with the **lowest-risk patient populations** were: - **Qatar: 15.3%** - **Kuwait: 21.8%** - **United Arab Emirates: 23.2%** These differences may reflect varying referral practices, differences in the underlying health of patient populations, or differences in how the risk factors were recorded. Understanding local risk profiles matters for patients when discussing surgical options with their care team. ## What This Means for Patients For patients considering bariatric surgery, the implications of this report are encouraging: - **Surgery is highly effective for weight loss.** The average 31.1% total body weight loss at one year is consistent with findings from many individual studies and confirms that real-world results match clinical trial results. - **Diabetes often goes into remission.** Nearly two-thirds of patients (64.2%) were able to stop their diabetes medication within a year — a life-changing outcome. The correlation with weight loss underscores the fundamental role that weight plays in metabolic health. - **Blood pressure and cholesterol improve dramatically.** Roughly half of patients came off their medications for these conditions. - **Surgery is minimally invasive.** With 99.1% of procedures performed laparoscopically and typical hospital stays of just 1–3 days, the surgical experience today is very different from the open surgeries of decades past. - **But access is uneven.** The wide gender gap (77.1% female overall) and the huge country-by-country variation in who gets surgery suggest that many people — especially men — face barriers to accessing surgical treatment. The report's preface also highlights a sobering reality: surgical treatment is "under-provided relative to the extent of disease" worldwide. Many people who could benefit from bariatric surgery are not receiving it. The registry's mission, as stated by Registry Chair Wendy Brown, is to provide "the most credible and transparent information available on bariatric/metabolic surgery" so that patients, doctors, insurers, and governments can make better decisions. ## What This Study Could Not Show It is important to understand the limitations of registry data, and the authors are transparent about them: - **Follow-up rates were low.** Only 30.1% of eligible patients had follow-up data recorded. If the patients lost to follow-up had different outcomes than those who were tracked, the results could be biased (in either direction). - **No statistical comparisons between countries were made.** The data are described but not used to declare one country or technique "better" than another, because the data have not been validated for that purpose. - **Complications and mortality were not analyzed.** The report explicitly states that no attempt was made to analyze these outcomes. - **The registry is not comprehensive.** Not all countries are included, and not all surgeries in participating countries were necessarily captured. The report's foreword calls the registry "still in its infancy." - **Data quality varies.** While 78.3% of baseline records were more than 70% complete, that means more than one-fifth of records had significant missing data. - **US data dominated the headline figures.** Since the US contributed roughly 335,000 of 833,687 records (about 40%), overall averages are heavily weighted toward American practice and patients. ## Recommendations for Patients and Providers Based on the report's findings and stated goals, here are practical takeaways for patients and the broader community: 1. **If you are considering bariatric surgery, know that the evidence is strong.** This registry, representing more than 800,000 real-world operations, confirms that weight-loss surgery produces substantial, sustained weight loss and major improvements in diabetes, blood pressure, and cholesterol. 1. **Ask your surgeon about expected outcomes and risks.** Your personal risk profile (using tools like the OSMRS score) can help you and your surgeon discuss the balance of benefits and risks in your individual case. 1. **Discuss which procedure is right for you.** With major variation in practice between countries and even between centers — from sleeve gastrectomy to Roux-en-Y gastric bypass to OAGB/MGB — it's worth understanding why your surgeon recommends the approach they do. 1. **Commit to follow-up care.** The low follow-up rate in this registry (30.1%) is a reminder that follow-up after surgery is just as important as the surgery itself. Regular check-ups help ensure the best long-term outcomes. 1. **Advocate for access.** The gender gap and under-provision of surgery worldwide suggest that many people who could benefit are not being offered surgery. If you or someone you know has severe obesity and related health conditions, it is worth having an informed conversation with a healthcare provider about whether surgery might be appropriate. The IFSO Global Registry Committee continues to work on improving the registry, with plans to identify **5–6 core outcome measures** (including patient-reported outcome measures, or PROMs), to develop a template protocol for new national registries, and to encourage national registries to capture at least 80% of all procedures performed in their countries. These improvements will make future reports even more useful for patients and clinicians alike. ## Frequently Asked Questions ### How much weight can I expect to lose one year after bariatric surgery? In a registry of 833,687 operations from 61 countries, patients with follow-up data lost an average of 31.1% of their total body weight one year after surgery. Two-thirds of patients taking diabetes medication no longer needed it. The weight loss was directly related to improvements in diabetes. ### Will I still need diabetes medication after weight-loss surgery? Across 833,687 surgeries recorded worldwide, 64.2% of patients taking diabetes medication no longer needed it one year after surgery. The chance of stopping medication increased with greater weight loss. Blood pressure and cholesterol medications were also stopped in about half of patients. ### How long is the hospital stay for bariatric surgery? Average hospital stay was about one day for gastric banding, two days for sleeve gastrectomy, and two days for gastric bypass. One anastomosis gastric bypass averaged 2.8 days. Almost all surgeries (99.1%) were performed laparoscopically, so recovery in the hospital is typically quick. ### What were the limitations of this bariatric surgery registry report? The report noted that only 30.1% of eligible patients had follow-up data, so results might be biased. Complications and mortality were not analyzed. No statistical comparisons between countries were made because the data were not validated. US data made up about 40% of all records, heavily influencing overall averages. ### Does bariatric surgery improve high blood pressure and cholesterol? Yes. In the registry, 45.4% of patients taking high blood pressure medication no longer needed it one year after surgery, and 51.8% stopped cholesterol medication. Improvement in sleep apnea and acid reflux was also seen, though the degree varied by surgery type. ## Source Information **Original Report Title:** Fifth IFSO Global Registry Report 2019 (5th IFSO Global Registry Report, September 2019) **Authors/Preparers:** Almino Ramos MD MSc PhD FACS FASMBS; Lilian Kow BMBS PhD FRACS; Wendy Brown MBBS PhD FACS FRACS; Richard Welbourn MD FRCS; John Dixon PhD FRACGP FRCP Edin; Robin Kinsman BSc PhD; Peter Walton MA MB BChir MBA FRCP **Publisher:** IFSO (International Federation for the Surgery of Obesity and Metabolic Disorders) and Dendrite Clinical Systems Ltd, September 2019. ISBN 978-1-9160207-3-3. **Related peer-reviewed publications cited in the report:** - Welbourn R, Pournaras DJ, Dixon J, et al. "Bariatric Surgery Worldwide: Baseline Demographic Description and One-Year Outcomes from the Second IFSO Global Registry Report 2013–2015." *Obesity Surgery*. 2018; 28(2): 313–322. - Welbourn R, Hollyman M, Kinsman R, et al. "Bariatric Surgery Worldwide: Baseline Demographic Description and One-Year Outcomes from the Fourth IFSO Global Registry Report 2018." *Obesity Surgery*. 2019; 29(3): 782–795. *Note: This patient-friendly article is based on a published registry report containing peer-reviewed research. It is intended for informational purposes and is not a substitute for professional medical advice. Always consult a qualified healthcare provider regarding your individual medical situation.* --- Publisher: Diagnostic Detectives Network (https://diagnosticdetectives.com) — independent multi-expert medical second opinions, worldwide, private-pay. Author byline: Anton Titov, MD, PhD. Contact: https://diagnosticdetectives.com/pages/contact Canonical page: https://diagnosticdetectives.com/products/understanding-weight-loss-surgery-worldwide-the-2019-ifso-global-registry-report-explained