What Is Bariatric Surgery?

Bariatric surgery, also known as metabolic surgery, is a medical treatment used to support people living with obesity, a chronic health condition influenced by biology, genetics, environment, and metabolism. These procedures work by changing how the body regulates hunger, fullness, and blood sugar — not simply by restricting food intake.

Depending on the procedure, surgery may:

• reduce stomach size so smaller meals feel satisfying
• change gut hormones that influence appetite and cravings
• improve blood sugar regulation
• reduce calorie absorption

Many people notice that food noise quiets, fullness lasts longer, and eating feels more manageable after surgery.

Who Might Benefit?

Metabolic surgery may be considered for individuals:

• living with obesity-related health conditions (such as type 2 diabetes, sleep apnea, or hypertension)
• whose weight significantly impacts daily life or long-term health when evidence-based treatments, including nutrition therapy, behavioural support, and/or medications have not provided enough benefit

Surgery is not a failure of lifestyle change. Most people pursuing surgery have already made substantial efforts to improve their health.

Typical Referral Criteria in Canada

While criteria vary slightly by province, common eligibility includes:

• Age 18 years or older
• BMI ≥ 40 or a BMI ≥ 35 with conditions such as: type 2 diabetes, hypertension, sleep apnea, coronary heart disease and GERD

If you would like to know the exact referral criteria in your location, your doctor can help determine eligibility and referral pathways.

Types of Bariatric Surgery in Canada

Sleeve Gastrectomy

A large portion of the stomach is removed, creating a smaller sleeve-shaped stomach.

• Smaller portions feel satisfying
• Hunger hormones decrease
• Nutrient absorption largely unchanged

This video provides a brief overview of the surgery: https://myhealth.alberta.ca/Health/pages/conditions.aspx?hwid=abq5755

Roux-en-Y Gastric Bypass

A small stomach pouch is created and part of the small intestine is bypassed.

• Reduces intake
• Changes hunger and fullness hormones
• Improves blood sugar regulation
• Reduces absorption of some nutrients
• This video provides a brief overview of the surgery: https://myhealth.alberta.ca/Health/pages/conditions.aspx?hwid=abq5755

Duodenal Switch

A sleeve procedure combined with a larger intestinal bypass.

• Greater average weight loss
• Higher risk of nutritional deficiencies
• Requires closer lifelong monitoring

How Effective Is Surgery?

Bariatric surgery is currently one of the most effective long-term treatments for people living with obesity.

Average total body weight loss (outcomes vary between individuals):

• Sleeve gastrectomy: ~20–30% (For example, a person starting at 300 lbs might typically lose around 60–90 lbs, meaning their weight after recovery may fall somewhere between 210 and 240 lbs)
• Gastric bypass: ~25–35%
• Duodenal switch: ~30–40%

Research shows surgery can:

✓ induce remission of type 2 diabetes, or reduce blood sugar levels often resulting in needing less diabetes medications

✓ improve sleep apnea

✓ lower blood pressure and cholesterol

✓ reduce cardiovascular risk

✓ improve mobility and quality of life

Surgery is a powerful tool, but it is not a cure. Obesity is a chronic condition, and the body naturally adapts over time. Some weight regain is common and expected. This reflects normal biology, not a lack of effort or success.

Long-term health outcomes are supported by:

• Structured eating patterns
• Adequate protein intake
• Strength-based movement
• Ongoing medical follow-up

Lifelong Care After Surgery

Because surgery permanently changes digestion, ongoing care is essential for health and safety.

This includes:

• daily vitamin and mineral supplementation
• regular bloodwork (at least annually)
• prioritising protein intake
• resistance training to preserve muscle mass

These steps help prevent nutritional deficiencies and support long-term wellbeing.

Possible Side Effects and Risks

All surgeries carry risks. Experiences vary, but some people may notice:

• Changes in food tolerance (certain breads or dense foods may feel uncomfortable)
• Dumping syndrome after sugary or fatty foods (more common after bypass)
• Constipation, especially early after surgery
• Hair thinning during periods of rapid weight loss
• Loose skin following significant weight loss
• Nutrient deficiencies without proper supplementation

Alcohol Use After Surgery - Alcohol impacts the body differently after bariatric surgery. It is absorbed more quickly and can reach higher levels in the bloodstream with smaller amounts. Hormonal and brain reward changes may also increase sensitivity to alcohol’s effects. Because of this, people who have had bariatric surgery have a higher risk of developing alcohol-related problems.

Is Surgery Right for Me?

There is no single “right” choice, only the choice that best aligns with your health needs, goals, and preferences.

Questions to consider:

• How is my weight affecting my health or daily life?
• What treatments have I already explored?
• Am I prepared for lifelong follow-up and supplementation?
• Do I feel informed about both benefits and risks? - For many people, bariatric surgery can be life-changing. For others, different treatments may feel more appropriate.

Next Steps

• If you are curious about bariatric surgery:
• Speak with your Constant Health dietitian
• Discuss referral options with your physician
• Ask questions! Understanding your options is an important first step

You do not need to decide everything at once. Learning more is simply part of exploring what care may best support your long-term health.

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