What Is Bariatric Surgery? Types, Benefits, and Risks Explained

April 28, 2025

Bariatric surgery refers to various surgical procedures that alter your digestive system to promote weight loss. Read more here.

Bariatric surgery has become one of the most effective long-term solutions for severe obesity, with studies showing it can help patients lose 50-80% of their excess weight and maintain this loss for over a decade (1). But what exactly does this life-changing procedure entail?

Understanding Bariatric Surgery

Bariatric surgery refers to various surgical procedures that alter your digestive system to promote weight loss. These operations work through two primary mechanisms:

Restriction – Reducing stomach size to limit food intake
Malabsorption – Bypassing parts of the small intestine to decrease calorie absorption

According to the American Society for Metabolic and Bariatric Surgery (ASMBS), these procedures are typically recommended for:

Individuals with a BMI ≥40
Those with BMI ≥35 who have obesity-related conditions like:
- Type 2 diabetes
- Hypertension
- Sleep apnea
- Severe joint problems (2)

The 4 Main Types of Bariatric Surgery

1. Gastric Sleeve (Sleeve Gastrectomy)

How it works: Surgeons remove about 80% of the stomach, leaving a banana-shaped “sleeve”

Pros:

No intestinal rerouting
Lower risk of nutritional deficiencies
Effective for most patients (50-60% excess weight loss)

Cons:

Irreversible
May worsen acid reflux

Ideal for: First-time patients with BMI 35-50

2. Gastric Bypass (Roux-en-Y)

How it works: Creates a small stomach pouch and reroutes the small intestine

Pros:

Faster initial weight loss
Excellent for diabetes remission
Long-term success (60-70% excess weight loss)

Cons:

More complex procedure
Higher risk of dumping syndrome

Ideal for: Patients with severe GERD or type 2 diabetes

3. Adjustable Gastric Band

How it works: Places an inflatable silicone band around the upper stomach

Pros:

Reversible
No cutting/stapling of stomach

Cons:

Lower weight loss results (40-50%)
Frequent follow-ups needed for adjustments

Ideal for: Patients wanting least invasive option

4. Biliopancreatic Diversion with Duodenal Switch (BPD/DS)

How it works: Combines sleeve gastrectomy with intestinal bypass

Pros:

Most effective for super obesity (BMI >50)
Highest long-term weight loss (70-80%)

Cons:

Highest complication risk
Requires strict vitamin compliance

Ideal for: Patients with BMI >50 who commit to lifelong follow-up

Comparative Results: Weight Loss Surgery Types

Procedure	Avg. Excess Weight Loss (1 Yr)	Hospital Stay	Recovery Time	Complication Rate
Gastric Sleeve	60%	1-2 days	2-3 weeks	5-10%
Gastric Bypass	70%	2-3 days	3-4 weeks	10-15%
Gastric Band	40%	Outpatient	1-2 weeks	15-20%
BPD/DS	80%	3-4 days	4-6 weeks	15-25%

Data from ASMBS 2022 Clinical Guidelines (3)

Health Benefits Beyond Weight Loss

Bariatric surgery patients often experience remarkable improvements in obesity-related conditions:

Type 2 Diabetes: 80% achieve remission or significant improvement (4)
Hypertension: 60-70% reduce or eliminate medications
Sleep Apnea: 85% see resolution of symptoms
Joint Pain: 70% report reduced pain and increased mobility
Fertility: PCOS symptoms improve in 90% of women (5)

Potential Risks and Complications

While modern bariatric surgery is safer than ever (mortality rate <0.3%), patients should understand potential risks:

Short-term (≤30 days post-op):

Bleeding (2-4% of cases)
Blood clots (1-2%)
Leaks at surgical connections (1-3%)

Long-term:

Nutritional deficiencies (iron, B12, calcium)
Dumping syndrome (especially with bypass)
Gallstones (30% of patients)
Need for revision surgery (5-10% at 10 years)

The Bariatric Surgery Process: What to Expect

Pre-Op Evaluation (3-6 months)
- Medical clearance
- Nutritional counseling
- Psychological assessment
Surgery Day
- Most procedures take 1-3 hours
- Typically laparoscopic (small incisions)
- 1-3 night hospital stay
Recovery Timeline
- Return to work: 2-4 weeks
- Full recovery: 6-8 weeks
- Most weight loss occurs in first year

Life After Surgery: Long-Term Success Factors

Diet:

Progressive stages (liquids → purees → solids)
Focus on protein (60-80g daily)
Avoid sugary/fatty foods

Exercise:

Start walking immediately post-op
Build to 150+ minutes/week
Strength training preserves muscle

Follow-Up Care:

Monthly visits first year
Quarterly years 2-5
Annual visits lifelong

Frequently Asked Questions

Q: How much weight will I lose?
A: Most patients lose:

1 month: 15-20 lbs
6 months: 50-80 lbs
1 year: 70-100+ lbs

Q: Will my insurance cover it?
A: Most plans cover if you meet NIH criteria. Medicare/Medicaid typically approve with proper documentation.

Q: Can the weight come back?
A: About 20% regain significant weight by 5 years, usually due to:

Not following diet
Lack of exercise
Missing follow-ups

Q: Will I need plastic surgery after?
A: About 30% choose body contouring procedures for excess skin after losing 100+ lbs.

Is Bariatric Surgery Right for You?

While highly effective, bariatric surgery requires lifelong commitment to:

Dietary changes
Vitamin supplementation
Regular exercise
Medical follow-up

The best candidates are:

Motivated to change lifestyle
Free from uncontrolled mental health issues
Committed to long-term care

Next Steps:

Calculate your BMI
Document weight loss attempts
Schedule consultation with bariatric specialist

Citations:

Sjöström L. (2013). New England Journal of Medicine
ASMBS Guidelines (2022)
Aminian A, et al. (2021). JAMA
Arterburn DE, et al. (2020). Diabetes Care
Teitelman M, et al. (2016). Fertility and Sterility

Internal Links:

Although bariatric surgery is an excellent treatment for weight loss, it requires a significant lifelong commitment to diet and physical activity changes to be effective in the long term.

When more calories are consumed than the body needs to function, body fat begins to accumulate and causes weight gain. Environmental, hormonal, metabolic, surgical, behavioral, and anatomical causes can contribute to excess calorie intake, also known as metabolic overeating.

Read More: What Is Bariatric Surgery? Types, Benefits, and Risks Explained

Weight gain after bariatric surgery

Weight relapse is primarily a physiological phenomenon, not a failure of willpower. Comorbidities before weight loss are likely to return when the weight returns. Within 2-5 years after surgery, almost a third of people gain more than 25% of their original weight. According to one study, more than 40% of patients who underwent bariatric surgery in the 10 years prior gained weight. Detecting weight gain early enough to take steps to reverse or limit weight gain is the best way to prevent the return of comorbidities.

From MVSA’s clinical experience, patients who visit the clinic regularly tend to gain less weight than those who do not return for follow-up.

Reasons For Weight Regain Post Bariatric Surgery

The chronic nature of obesity and the tendency of patients to slip back into their old habits are the main causes of weight gain in the vast majority of patients. Other causes include:

Stretching of the gastric sac (pouch dilatation).
Stretching of the intestinal pouch connection (stoma dilatation).
Problems with the adjustable gastric band system (hole in the tube, balloon leak, detached port, etc.).
Improper connection (gastric-gastric fistula due to broken staple suture).

In rare cases, medical circumstances such as pregnancy, thyroid, and adrenal problems, and new medications can cause weight gain.

Talk to your doctor if you start to gain weight after bariatric surgery. You may be able to determine the cause of the weight gain. To pinpoint the causes of weight gain—medical, psychological, or lifestyle—you may need a more thorough assessment.

Lifestyle Changes to Avoid Weight Regain

Your overall health depends on whether you eat enough healthy proteins. Your body uses protein to develop skin, muscles, bones, and blood. Protein makes you feel full faster and for a longer period of time, which helps you lose and maintain weight.

Track Your Protein Intake

According to research, tracking your diet can help you lose twice as much weight as people who don’t. Protein tracking is simple with an app. The app will calculate the amount of protein you eat after finding the food. This is useful, especially when you’re dining out (more on that in a bit).

Then how much protein should you consume? According to the CDC, protein should make up 10% to 35% of your daily calories. This is about 56 grams of protein for adult men compared to 46 grams for women.

Stay Away from Milk Products

If after bariatric surgery, you may find that you are lactose intolerant. As a result, your bariatric surgeon may advise you to replace milk with soy milk and low-lactose milk substitutes such as Lactaid.

Fruits

Eat high-fiber fruits such as blackberries, raspberries, apples, avocados, blueberries, strawberries, pears, and oranges with or between meals. Try pairing one serving of fresh fruit with a serving of protein-rich Greek yogurt or cottage cheese for a nutritious, fiber and protein-rich snack.

Vegetables

Stick to low-carb vegetables rich in fiber, flavonoids, and antioxidants. You will eat more food while consuming fewer calories if you put these vegetables on your plates. Green beans, broccoli, tomatoes, asparagus, cauliflower, spinach, and bell peppers are delicious vegetables to put on your plate.

Eat Smaller Meals More Often

Stick to mini meals rather than three large meals a day. You will feel full all day if you eat these small meals more often. Eating actual food instead of just snacking will make you less prone to overeating!

Don’t Drink Too Many Calories

Your doctor will set a daily calorie restriction for you after bariatric surgery. Once again, the app can make sure you stick to your calorie budget. If you are using a calorie-counting app, you will find that some drinks are high in calories. For example, a 12-ounce bottle or can of soda contains 150 or more calories. So that you can use your calories for high-calorie foods like protein, vegetables, and fresh fruits, you would be much better off drinking calorie-free drinks or, better yet, plain water.

Avoid Sugary Foods

If you’re worried about gaining weight again, you should avoid foods high in fat or sugar. When presented with junk food options such as cake, ice cream, candies, or bakery items, take them off the table for the best weight loss results.

Explore remedies for weight gain after Bariatric Surgery

MVSA professionals may recommend a bariatric revision if the cause of your weight gain is outlet dilation. Transoral gastric outlet reduction, called bariatric revision, is used to treat outlet dilatation.

The hole is returned to its preoperative size with a few sutures. You feel more satisfied after eating when the size of the outlet is changed.

The endoscope is used in bariatric revision and non-surgical treatment to apply several sutures in the required places. Since no incisions are made, the process is less invasive and takes much less time because it is non-surgical. In addition, you lose weight at the same rate as before the initial treatment.

Find the Best Bariatric Surgeon for Best Solution

With these lifestyle choices and other tips, you can lose a lot of weight and keep it off forever. Weight gain is possible, but following your bariatric surgeon’s advice on proper healing after weight loss surgery can minimize or avoid the problem entirely.

By choosing the best bariatric surgeon you can find, you can guarantee long-term success before, during, and after your procedure. Sleeve gastrostomy, gastric bypass, and non-surgical gastric balloon are some of the common bariatric surgeries that MVSA surgeons have a proven track record of performing.

The surgical staff at MVSA can help you achieve your surgical weight loss and overall physical health goals. Call now to schedule a consultation and get started with bariatric surgery on the road to healthier living.