Bariatric Surgery (Metabolic & Weight-Loss Surgery)

Bariatric surgery (increasingly called metabolic and bariatric surgery, or MBS) is a group of operations that treat severe obesity and its related diseases by changing the stomach and, in some procedures, the small intestine. It is recognized as the most effective and durable treatment for obesity — a chronic, relapsing disease — producing far greater and longer-lasting weight loss than diet, exercise, or medication alone, along with remission or improvement of conditions such as type 2 diabetes, high blood pressure, high cholesterol, and sleep apnea (Scientific Reports, 2024; Lancet, 2024).

Find Your Path: Three Routes Through Bariatric Care

Where you start depends on where you are now. Choose the route that fits you.

Route 1: Choosing your first procedure

• Am I a candidate? Start with the candidacy guide and who qualifies under modern criteria.
• Comparing operations. The sleeve, gastric bypass, SADI-S, duodenal switch and one-anastomosis bypass each trade weight loss against nutrition demands and reflux risk. See sleeve vs. bypass vs. DS vs. SADI and how Dr. de la Cruz-Muñoz chooses.
• What changes the choice. Existing reflux usually favors bypass over sleeve; diabetes and higher BMI may favor a more powerful operation; and malabsorptive procedures require a lifelong commitment to vitamins and labs. See diabetes remission and reflux after bariatric surgery.
• Options without surgery. Endoscopic sleeve gastroplasty, the gastric balloon, and the medical weight loss program with GLP-1 medications. See GLP-1 medications vs. bariatric surgery.

Route 2: Getting help after a previous operation

• Weight regain. After a sleeve or after a bypass, options range from medication and endoscopic revision (TORe) to surgical revision.
• Reflux. Reflux after sleeve gastrectomy and bile reflux after a mini-bypass often need anatomic testing before treatment.
• Complications. Marginal ulcers, strictures, dumping syndrome, low blood sugar, malnutrition and chronic abdominal pain.
• Revision. Find the right operation for your problem in the revisional bariatric surgery hub.

Route 3: Preparing for surgery and long-term follow-up

• Before surgery. Insurance coverage, the pre-operative education guide, the pre-operative checklist and mental preparation.
• Recovery. The first 30 days, the recovery guide, and discharge warning signs.
• For life. Lifelong follow-up, vitamins, annual labs, protein and exercise.
• Traveling to Miami. Most of the evaluation happens from home, with approximately one week in Miami for surgery. See the out-of-town patient guide.

Your bariatric care team

Surgery is one day; the program is for life. Dr. de la Cruz-Muñoz’s patients are supported by:

• A bariatric coordinator who works both in the office and at HCA Florida Mercy Hospital, guiding you from first visit through surgery.
• A dedicated bariatric office team, all bilingual in English and Spanish.
• A nutritionist for pre-operative preparation and long-term eating plans.
• Body composition analysis at every visit, so progress is measured as fat lost and muscle preserved, not just pounds on a scale.
• Support groups online and in person, open to patients from more than 25 years of practice.
• Medical weight loss with GLP-1 medications when extra help is needed before or after surgery.

Modern bariatric surgery is almost always performed with minimally invasive (laparoscopic or robotic) techniques, which have largely replaced open surgery and reduced hospital stay and complications (The Obesity Society, 2025). The five most commonly used procedures in the United States are sleeve gastrectomy, Roux-en-Y gastric bypass, biliopancreatic diversion with duodenal switch (BPD/DS), single-anastomosis duodeno-ileal bypass with sleeve (SADI-S), and adjustable gastric banding — with sleeve gastrectomy and gastric bypass together accounting for more than 90% of operations (The Obesity Society, 2025; JAMA, 2023).

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For an overview of every bariatric option offered at the Miami practice, see Bariatric Surgery in Miami, FL. Patients coming from outside Florida can also review the Miami Bariatric Destination Program.

Although the exact mechanisms are still being clarified, bariatric surgery produces weight loss and metabolic improvement through three main mechanisms, which combine differently depending on the procedure (The Obesity Society, 2025):

• Restriction: Reducing the size of the stomach limits how much food can be eaten and promotes earlier, longer-lasting fullness (e.g., sleeve gastrectomy, gastric banding) (Heart Failure Reviews, 2022).

• Malabsorption: Rerouting the small intestine reduces how many calories and nutrients the body absorbs (e.g., duodenal switch, SADI-S) (Heart Failure Reviews, 2022).

• Hormonal and metabolic change: Altering the path of food changes gut hormones such as GLP-1 and ghrelin, which reduce appetite, increase satiety, and improve blood-sugar control — often before major weight loss occurs (The Obesity Society, 2025; Cochrane Database of Systematic Reviews, 2024).

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• Substantial, durable weight loss, typically 25–30% of total body weight for the most common procedures, sustained at 5–20 years (JAMA, 2023; New England Journal of Medicine, 2017).

• Type 2 diabetes remission in a large proportion of patients, with benefits most likely when surgery is performed before insulin is required (New England Journal of Medicine, 2017; JAMA, 2018).

• Improvement or resolution of high blood pressure, high cholesterol, obstructive sleep apnea, and fatty liver disease (JAMA, 2018; Lancet, 2024).

• Most effective treatment for obesity overall, outperforming lifestyle and medication alone for both weight loss and disease remission (Scientific Reports, 2024).

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Under the 2022 ASMBS/IFSO guidelines, bariatric surgery is recommended for (Scientific Reports, 2024; Obesity Surgery, 2026):

• Adults with a BMI ≥ 35 kg/m², regardless of whether obesity-related conditions are present.

• Adults with a BMI of 30–34.9 kg/m² who have metabolic disease such as type 2 diabetes.

• Asian patients at lower thresholds (obesity at BMI > 25, surgery considered at > 27.5 kg/m²).

Older (1991 NIH) criteria of BMI ≥ 40, or ≥ 35 with comorbidities, are still used by many insurers (Obesity Surgery, 2026). Candidacy also requires the ability to commit to lifelong dietary changes, supplementation, and follow-up, and is individualized after multidisciplinary evaluation (Lancet, 2024).

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Bariatric procedures are performed under general anesthesia, almost always laparoscopically or robotically through several small incisions. The specific steps depend on the operation chosen: sleeve gastrectomy removes most of the stomach; gastric bypass creates a small stomach pouch connected to the small intestine; and duodenal-switch-type procedures (BPD/DS, SADI-S) combine a sleeve with an intestinal bypass (JAMA, 2023; Diabetes, Obesity and Metabolism, 2025). Procedure selection is based on individualized goals, weight-loss targets, specific obesity-related conditions, surgical risk, local expertise, and patient preference (American Society for Metabolic and Bariatric Surgery, 2020).

Modern bariatric surgery is generally safe, with a perioperative mortality of roughly 0.03–0.2%, but as with any surgery there are risks that vary by procedure (Cochrane Database of Systematic Reviews, 2026).

• Early complications include anastomotic or staple-line leak, bleeding, stenosis, infection, and blood clots (venous thromboembolism) (JAMA, 2023; Cochrane Database of Systematic Reviews, 2026).

• Procedure-specific risk: Sleeve and gastric banding have the lowest serious-complication rates; bypass procedures carry more; BPD/DS has the highest (about 8%) (Cochrane Database of Systematic Reviews, 2026).

• Late complications can include acid reflux (especially after sleeve), marginal ulcer, internal hernia, bowel obstruction, dumping syndrome (after bypass), and gallstones (Cochrane Database of Systematic Reviews, 2026; Obesity Surgery, 2026).

• Nutritional deficiencies — of iron, vitamin B12, folate, vitamin D, calcium, and fat-soluble vitamins (A, E, K), zinc, and copper — can occur after all procedures and are greatest after malabsorptive operations, requiring lifelong supplementation and monitoring (Obesity Surgery, 2026; Cochrane Database of Systematic Reviews, 2024).

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Most patients go home within 1–3 days and resume normal activity within a few weeks. Diet advances in stages — clear liquids, full liquids, pureed foods, then solids — over several weeks under the guidance of the surgical team and a registered dietitian (American Society for Metabolic and Bariatric Surgery, 2020). Walking begins the day of surgery to reduce the risk of blood clots. Enhanced recovery after bariatric surgery (ERABS) pathways, including multimodal (opioid-sparing) pain control, are now standard and speed recovery (American Society for Metabolic and Bariatric Surgery, 2020).

Weight loss typically reaches its lowest point (nadir) at 1–2 years, followed by modest regain and then long-term stabilization. For gastric bypass, mean total weight loss is roughly 25–30% maintained out to 12–20 years, with durable comorbidity improvement (New England Journal of Medicine, 2017; Surgical Endoscopy, 2023). Some weight regain is common — over half of patients regain at least 20% of their lost weight after nadir — but most maintain substantial, clinically meaningful weight loss long term (International Journal of Obesity, 2026). Lifelong follow-up, including annual nutritional blood tests, is essential (Lancet, 2024).

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Explore Procedures by Category

Bariatric Surgery Procedures: Sleeve Gastrectomy, Gastric Bypass, One‑Anastomosis Gastric Bypass, SADI-S, Duodenal Switch, Magnetic Duodeno-Ileal Bypass with Sleeve, Adjustable Gastric Band Surgery, Medical Weight Loss Program.

Endoscopic Weight-Loss Procedures: Endoscopic Sleeve Gastroplasty, Gastric Balloon, Orbera Intragastric Balloon, Allurion Balloon, Endoscopic Balloon Removal, Transoral Outlet Reduction, Medical Weight Loss Program.

Sleeve Gastrectomy Revisions: Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion, Sleeve Gastrectomy to SADI-S Conversion, Sleeve Gastrectomy to Duodenal Switch Conversion, Sleeve to OAGB Conversion, Sleeve Gastrectomy to Magnetic Duodeno-Ileostomy Conversion, Re-Sleeve Gastrectomy, Hiatal Hernia Repair After Sleeve Gastrectomy, Gastric Sleeve Stricture Management.

Outcomes after bariatric surgery depend heavily on surgical experience, careful procedure selection, and a structured long-term follow-up program. Dr. de la Cruz-Muñoz offers comprehensive multidisciplinary evaluation, individualized procedure selection across the full range of modern operations — from sleeve gastrectomy to advanced duodenal-switch-type procedures — and a dedicated nutrition and monitoring program designed to maximize long-term success and safety.

Dr. de la Cruz-Muñoz has been performing bariatric surgery for over 25 years and has completed more than 9,000 bariatric operations — a volume few surgeons reach.

To learn how the process works locally, from your first visit to surgery and recovery, visit our bariatric surgery in Miami page.

Before choosing a surgeon, you may find our video 7 Questions That Predict Your Outcome helpful.

TBWL varies by procedure, generally increasing with the degree of intestinal rerouting:

• Sleeve gastrectomy: ~25% TBWL at 1 year (JAMA, 2023).

• Roux-en-Y gastric bypass: ~30% TBWL at 1 year; ~25–27% sustained at 12 years and beyond (JAMA, 2023; New England Journal of Medicine, 2017).

• SADI-S: ~38% TBWL at 5 years (Obesity Surgery, 2025).

• BPD/DS: the greatest and most durable, roughly 35–41% sustained long term (Surgical Endoscopy, 2022).

Individual results vary with procedure, starting weight, diet, activity, and adherence to follow-up.

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• Type 2 diabetes: Remission in roughly 60% at 7 years after gastric bypass, and higher after duodenal-switch-type procedures; best when performed before insulin dependence (JAMA, 2018; New England Journal of Medicine, 2017).

• High blood pressure and high cholesterol: Significant, sustained improvement or remission across procedures (JAMA, 2018).

• Obstructive sleep apnea and fatty liver disease: Frequent improvement or resolution (Lancet, 2024).

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Maintaining results depends on a high-protein diet, consistent daily supplementation, regular physical activity, behavioral support, and keeping all follow-up appointments so that weight and nutrition trends are caught early (Lancet, 2024; International Journal of Obesity, 2026). When significant regain occurs, options include intensified lifestyle and behavioral support, anti-obesity (GLP-1-based) medications, and revisional surgery (International Journal of Obesity, 2026).

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Acid reflux is an important consideration in procedure selection. Sleeve gastrectomy can cause or worsen reflux, whereas gastric bypass generally improves it and is often preferred for patients with significant GERD. Duodenal-switch-type procedures preserve the pylorus, which tends to limit reflux (Cochrane Database of Systematic Reviews, 2026). Patients with significant reflux require individualized evaluation.

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Revisional bariatric surgery may be considered for inadequate weight loss, significant weight regain, or complications such as severe reflux. Common pathways include converting a sleeve to a gastric bypass (often for reflux) or to a SADI-S/duodenal switch (for more weight loss) (Obesity Surgery, 2026). Procedure choice is individualized based on the original operation, the problem being addressed, and nutritional status.

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Rapid weight loss carries a risk of losing muscle along with fat. Adequate protein intake (generally at least 60 g/day, up to 1.5 g/kg of ideal body weight) combined with resistance exercise helps preserve lean muscle mass, and protein status is monitored at follow-up (American Association of Clinical Endocrinology, 2019).

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Most insurers require documentation of a qualifying BMI (commonly ≥ 40, or ≥ 35 with obesity-related conditions), a medically supervised weight-management program, and nutritional and psychological evaluations, along with specialist clearances (American Society for Metabolic and Bariatric Surgery, 2020; JAMA, 2023). Requirements vary by plan; our team verifies specific coverage before scheduling.

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• Comprehensive multidisciplinary evaluation — medical, nutritional, and psychological (American Society for Metabolic and Bariatric Surgery, 2020; Lancet, 2024).

• Baseline laboratory testing including a full nutritional/micronutrient panel, and usually an upper endoscopy (Surgical Endoscopy, 2022).

• A pre-operative liquid or reduced-calorie diet (often 2–6 weeks) to reduce liver size and surgical risk (Surgical Endoscopy, 2022).

• Smoking cessation, age-appropriate cancer screening, and arrangements for long-term supplements and follow-up (American Society for Metabolic and Bariatric Surgery, 2020).

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A staged diet progresses from clear liquids to full liquids, pureed foods, and then solids over several weeks, guided by a registered dietitian (American Association of Clinical Endocrinology, 2019). Lifelong supplementation is required and tailored to the procedure, typically including a multivitamin, calcium citrate with vitamin D, iron, and vitamin B12, with additional fat-soluble vitamins after malabsorptive operations. A minimum protein intake of about 60 g/day is recommended, with doses and labs adjusted over time (American Association of Clinical Endocrinology, 2019; JAMA, 2023).

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Walking begins the day of surgery. Light activity resumes within the first week or two, with a gradual return to full exercise over 4–6 weeks. Once cleared, a combination of regular aerobic activity and resistance training supports muscle preservation and long-term weight maintenance.

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International patients should plan to stay in Miami for approximately one week for bariatric surgery. Much of the evaluation, including the consultation, nutrition review and records, can be completed virtually before you arrive, and all follow-ups can be completed virtually. Miami's direct flights to Latin America, the Caribbean and Europe make travel straightforward for many patients.