Western Zone Obesity Network · Patient Guide
Understanding weight-loss surgery: how it works, who it’s for, the benefits and risks, and what to expect before and after.
Welcome
If you are reading this, you or someone you love may be thinking about bariatric surgery. It’s an important step, and we’re here to help you understand your options. The most important thing to know is this: struggling with your weight is not your fault. Obesity is a medical condition, not a choice. Your body has powerful systems that control hunger, cravings, and how it stores fat, and they can make managing weight very hard, no matter how hard you try.
Bariatric surgery is not “taking the easy way out.” It is a real medical treatment for a real medical condition, and it changes your body’s biology to help you lose weight and improve your health.
About the Network
The Western Zone Obesity Network (WZON) was created to improve obesity care in Nova Scotia. We bring together patients, doctors, nurses, dietitians, and other healthcare providers to give you the best possible care. We believe the best care happens close to home, and your family doctor will be your main point of contact throughout your journey.
Understanding Bariatric Surgery
Many people think bariatric surgery simply makes your stomach smaller so you eat less. It does much more than that. Bariatric surgery is really a metabolic treatment: it changes how your body and brain communicate about hunger, fullness, and energy.
Bariatric surgery works with your biology instead of against it. It changes the automatic, unconscious systems that drive hunger and weight gain.
Types of Surgery
Both procedures are done using laparoscopic (keyhole) surgery through small incisions.
“Gastric sleeve” or “the sleeve”
The surgeon removes about 80% of the stomach, leaving a thin, banana-shaped stomach.
“Gastric bypass”
The surgeon creates a small pouch (about the size of an egg), then reconnects the small intestine in a “Y” shape, so food bypasses most of the stomach and the first part of the intestine.
Bypass may be recommended if you have severe acid reflux (GERD) that hasn’t responded to other treatments, type 2 diabetes that needs better control, or a previous sleeve with weight regain.
| Sleeve Gastrectomy | Gastric Bypass (RYGB) | |
|---|---|---|
| The surgery | 80% of stomach removed; irreversible | Small pouch + rerouted intestine; potentially reversible |
| Average weight loss | 20–25% of total body weight | 25–30% of total body weight |
| Surgery time | About 1 hour | About 1.5–2 hours |
| Vitamin needs | Daily multivitamin, B12, vitamin D, calcium | More supplements, due to less absorption |
| Often best for | Most patients; simpler procedure; those needing NSAIDs, prior surgeries, higher starting weight, IBD or cirrhosis | Severe diabetes/metabolic disease and severe acid reflux (GERD) |
Some problems can develop months or years after surgery. This table shows which are more associated with each procedure (more plus signs = more associated).
| Late complication | Sleeve | Bypass |
|---|---|---|
| Anastomotic (marginal) ulcer | — | + + |
| Stenosis / narrowing | + | + |
| Incisional hernia | + | + |
| Internal hernia | — | + |
| Gallstones & kidney stones | + | + |
| Dumping syndrome | — | + |
| Vitamin deficiency / malnutrition | + | + + |
| Chronic abdominal pain | + | + + |
| Low blood sugars | + | + + |
| Nausea / vomiting | + | + |
Your surgeon will recommend the best option for you based on your health conditions, not just which one has more weight loss.
Eligibility
To be considered for bariatric surgery in Nova Scotia, you must meet certain requirements.
There is no strict age or upper-weight limit, though your team will assess your individual situation (special assessment is needed for BMI over 60).
You must be smoke-free (no cigarettes, vaping, or cannabis) for at least 6 months before surgery. This is a safety requirement, not optional. Smoking greatly increases the risk of serious complications.
Surgery may not be right for you if you are currently smoking or using cannabis, have current problems with alcohol or drug use, have an untreated eating disorder, have severe mental-health problems that are not stable, or have medical conditions that make surgery too risky.
Bariatric surgery is covered by the Nova Scotia provincial health plan. You don’t pay for the surgery itself, but you will need to pay for meal replacement before surgery and multivitamins for life.
Benefits & Risks
| Complication | How often |
|---|---|
| Bleeding | 1–5 in 100 patients |
| Leak from a surgical connection | 1–3 in 100 patients |
| Blood clot in the legs | 1–2 in 100 patients |
| Blood clot in the lungs | About 1 in 200 patients |
| Death from surgery | Less than 1 in 100–1,000 patients |
The overall chance of having any complication is about 10%, and most complications can be treated successfully. Longer-term considerations include gallstones (from rapid weight loss), nutritional deficiencies (why vitamins are lifelong), marginal or internal hernias, dumping syndrome and low blood sugars (more common after bypass), and an increased risk of problems with alcohol in some people.
For most patients, the health risks of living with severe obesity are greater than the risks of surgery. Your healthcare team will help you understand your personal risk level.
What to Expect
These are averages. Some people lose more, some less, depending on genes, age, starting weight, hormones, and how you follow the program. Results that differ from average are not a “failure”; they are your biology.
The goal of bariatric surgery is to improve your health, not to reach a specific number on the scale. Many patients remain in the “obese” BMI category afterward yet see major gains in health, mobility, energy, and quality of life. That is success. Health improvements matter more than any number on a scale.
Knowing what to expect month by month can help you stay motivated:
| When | What usually happens |
|---|---|
| Months 1–3 | Weight loss is usually rapid, often 15–25% of your eventual total. Your body is adjusting to eating much less. |
| Months 3–6 | Loss continues steadily. You’ll notice real changes in how clothes fit, how you move, and how you feel. |
| Months 6–12 | Loss begins to slow. This is normal; your body is finding a new equilibrium. |
| Months 12–18 | Most patients reach their lowest weight somewhere in this window. The rate of loss tapers off significantly. |
| 18–24 months+ | Weight typically stabilizes. A small amount of regain (5–10%) is a normal biological response, not a failure. |
Throughout this journey, the most important thing is to focus on healthy habits, not the number on the scale.
Getting Ready
Preparation takes time and effort. It matters for two reasons: it makes the surgery safer, and it builds the skills you need for long-term success.
Step 1: Referral and initial assessment (weeks 1–4). After your doctor sends a referral, our team reviews it and contacts you to schedule your first appointment, where you’ll review your health history and goals and learn what lies ahead.
Step 2: Medical assessments (months 1–4). Your team arranges testing to make sure surgery is safe for you. This may include:
Step 3: Working with a dietitian (ongoing). A dietitian who specializes in bariatric surgery helps you learn the post-surgery diet stages, practise eating slowly and recognizing fullness, understand your protein and fluid goals, cut back on ultra-processed foods and sugary drinks, and start your supplements. This is one of the most important parts of your preparation.
Step 4: Surgeon consultation and booking. Once assessments are complete, your surgeon reviews your results, recommends the best procedure for you and explains why, discusses your specific risks, answers your questions, and books your date.
Step 5: Final preparation (2–4 weeks before). You’ll attend a pre-operative education session, start the pre-surgery diet, stop certain medications as directed, and arrange time off work and support at home.
For two to four weeks before surgery, you’ll follow a special liver-shrinking diet, one of the most important steps in your preparation.
Your liver sits right next to your stomach. Extra weight makes it store fat and enlarge, which makes surgery technically harder and riskier. The pre-surgery diet shrinks your liver, giving the surgeon better access and making the procedure safer.
The first 2–3 days are usually the hardest, and you may feel hungry, irritable, or have headaches as your body adjusts. These symptoms typically improve, and many people report more energy after the first few days. This diet is mandatory; if your surgeon feels you haven’t followed it, surgery may be postponed for your safety.
Some medications need to be adjusted or stopped. Your team reviews your full list, but common changes include:
Do not stop any medication without talking to your healthcare team first.
Surgery changes more than your body. Begin developing coping strategies other than food now, set realistic expectations (surgery is a powerful tool, not a fix for every problem), and tell the people closest to you so you have support. At home, stock approved clear fluids and protein shakes, set up a comfortable resting area, arrange a driver and someone to stay with you for the first few days, and plan 2–4 weeks off work. The day before, follow your surgeon’s eating instructions (usually nothing after midnight), shower with the antibacterial wash provided, remove nail polish and jewellery, and lay out loose clothing.
Knowledge: understand obesity as a medical condition, the risks and benefits, realistic expectations, and life after surgery. Nutrition: work with a dietitian, know the post-surgery diet stages, get enough protein, reduce ultra-processed foods, take supplements. Lifestyle: smoke- and cannabis-free for at least 6 months, regular activity, behaviour-change support if needed. Medical: established primary care, blood work done, sleep-apnea test done (CPAP if needed), mental health stable, cancer screening current, medications reviewed, NSAIDs avoided. Support: a support person for recovery and a plan for follow-up.
After Surgery
Most patients stay in hospital for 1–2 nights. You’ll start sipping clear fluids, be encouraged to walk the same day (this helps prevent blood clots), and be monitored for early complications. The first 4–6 weeks at home are for healing; feeling tired is normal, so rest as needed and walk as much as you can.
Your stomach needs time to heal, so you’ll advance through a careful diet progression. Your dietitian guides each stage, so don’t skip stages or advance faster than recommended.
This is a summary. For the complete picture (the bariatric plate, protein targets, food lists, sample meals, and each eating stage in detail), see the Nutrition Guide for Bariatric Surgery.
| Stage | Timing | What it looks like |
|---|---|---|
| 1. Clear fluids | Days 1–2 (hospital) | Water, clear broth, sugar-free gelatin and popsicles, herbal tea. Small sips (about 1 tbsp at a time), no straws. Aim for ~1 cup per hour while awake. |
| 2. Full fluids | Weeks 1–2 | Protein shakes (aim for 60 g protein/day), skim/1% or unsweetened plant milk, strained cream soups, smooth sugar-free yogurt. At least 1.5 L fluid daily. |
| 3. Pureed foods | Weeks 3–4 | Baby-food / smooth-pudding texture: pureed lean meats, beans and lentils, mashed banana, applesauce, smooth hummus, soft scrambled eggs. Meals take 20–30 min; stop at first fullness. |
| 4. Soft foods | Weeks 5–8 | Moist, tender, easy to chew: baked fish, canned tuna/salmon, soft chicken or ground meat, soft-cooked vegetables, ripe or canned fruit, cottage cheese, oatmeal. Protein first; chew 20–30 times. |
| 5. Regular foods | Week 9 onward | Wider variety in small portions, protein first, one new food at a time. Bread, pasta, rice, tough meats, and raw vegetables may not sit well. Keep avoiding sugary foods, carbonated drinks, and fried foods. |
Staying hydrated takes real effort because your stomach is small. Aim for at least 1.5 litres (6 cups) a day, sip constantly (carry a water bottle), and don’t drink during meals or for 30 minutes after eating, because drinking with meals flushes food through too quickly. Watch for dark urine, dizziness, dry mouth, headache, or fatigue. If plain water is hard to tolerate, try lemon, cucumber, or herbal tea.
After surgery your body absorbs fewer nutrients, so daily vitamins and minerals are a lifelong requirement, not optional. Chewable, liquid, or sublingual forms are easiest for the first few months. Buy them before surgery, set a daily routine, and never stop, because deficiencies develop slowly and silently.
| Supplement | Daily dose | Notes |
|---|---|---|
| Bariatric multivitamin (with minerals) | 1 complete multivitamin | Chewable/liquid for the first 3 months, then tablets |
| Calcium citrate | 1200–1500 mg, in divided doses | Split into 2–3 doses (~500 mg absorbed at a time). Must be citrate, not carbonate |
| Vitamin D3 | 2000–3000 IU | Often taken with calcium; adjusted to blood levels |
| Vitamin B12 | 1000 mcg sublingual, or injection | Sublingual absorbs more reliably than a swallowed tablet |
| Iron | As recommended by blood work | Menstruating women often need it; take 2+ hours apart from calcium |
All of the above, with higher doses because bypass patients absorb less:
| Supplement | Daily dose | Notes |
|---|---|---|
| Bariatric multivitamin | 2 per day (or 1 high-potency) | Higher doses needed |
| Calcium citrate | 1500–2000 mg, in divided doses | The calcium-absorbing part of the intestine is bypassed |
| Vitamin B12 | 1000 mcg sublingual, or monthly injection | Absorption is more affected after bypass |
| Iron | Often 45–60 mg | Take with vitamin C, away from calcium |
| Vitamin D3 | 3000+ IU | Higher doses often needed |
| Thiamine (B1) | In multivitamin; more if deficiency suspected | Report persistent vomiting, which raises the risk |
| Problem | What to do |
|---|---|
| Constipation | Drink more fluids, stay active, try a stool softener |
| Diarrhea | Stick to clear fluids for 24 hours; avoid sugar-free products with sorbitol |
| Gas and bloating | Walk often; try simethicone (Gas-X) |
| Nausea or vomiting | Sip fluids slowly; don’t eat and drink at the same time; return to liquids if needed |
| Dehydration | Sip fluids all day; watch for dark urine, dizziness, dry mouth |
| Heartburn | Raise the head of the bed; don’t eat before bed; take medications as directed |
| Hair loss | Common at 3–6 months and usually temporary; ensure enough protein and vitamins |
| Feeling cold | With less insulation and fewer calories, dress in layers |
A wide range of emotions is normal: relief and excitement, but also frustration with the liquid diet, mood swings from rapid hormonal change, grief over losing food as comfort, and even brief “buyer’s remorse” that usually passes as the benefits arrive. Talk to someone, keep moving, and stay connected with your team. If sadness or anxiety persists beyond the first few weeks or interferes with daily life, reach out, because post-surgery depression is treatable. Most people return to desk work in 2–3 weeks, light physical work in 3–4 weeks, and heavy labour in 6 weeks or more.
Contact your surgeon or go to the emergency room for: vomiting lasting more than 24 hours; being unable to keep fluids down; severe stomach pain; fever over 38.5°C (101°F); signs of infection (redness, warmth, or drainage from incisions); chest pain or trouble breathing; or dehydration that doesn’t improve. In an emergency, call 911.
For Life
Bariatric surgery is a powerful tool, but it is not a cure. Long-term success depends on lifelong commitments:
Missing follow-up can lead to serious problems that develop silently. Nutritional deficiencies can cause nerve damage, bone loss, and other harm if not caught early. Your commitment to lifelong follow-up is as important as the surgery itself.
Your body processes alcohol differently now: you feel the effects faster, your blood alcohol rises higher for the same amount, effects last longer, and the risk of alcohol use disorder increases, and is highest 2–3 years after surgery, especially after bypass. Avoid alcohol completely for at least the first year. After that, be very cautious (one drink may affect you like two or three did before), never drink and drive, and tell your team if you notice yourself drinking more or relying on it to cope.
Surgery can improve fertility, especially with PCOS. Wait at least 12–18 months before becoming pregnant so your body can stabilize, and use reliable contraception in the meantime; oral pills may be less effective after bypass, so ask about an IUD or injection. When you’re ready, tell your team: you’ll need closer nutritional monitoring, and your vitamin doses may be adjusted. With proper planning, outcomes are excellent.
Surgery changes how you absorb medications. Avoid NSAIDs permanently after a bypass (use acetaminophen instead), watch for extended-release forms that may not absorb properly, and expect that diabetes, blood-pressure, and psychiatric medications may need dose changes under supervision. Always tell every doctor, dentist, and pharmacist that you’ve had bariatric surgery.
Dumping syndrome, more common after bypass, happens when sugary or high-fat food moves too quickly into the intestine. Early dumping (within 30 min) causes nausea, cramping, diarrhea, sweating, and a rapid heart rate; late dumping (1–3 hours) causes low-blood-sugar symptoms. Prevent it by avoiding sugary foods, eating small protein- and fibre-rich meals, and not drinking with meals. It’s unpleasant but not dangerous, and often reinforces healthier eating.
Some weight regain over time is normal and does not mean you have failed. It can come from your unique biology, the brain defending against weight loss, the stomach stretching slightly over years, a return of old habits, life stresses, or weight-promoting medications. If you notice regain, don’t give up, and reach out early. Options include reviewing your eating with a dietitian, adding weight-management medication, support for emotional eating, and, in some cases, revision surgery.
Resources & Contacts
Obesity is a medical condition, not a personal failure. Surgery changes your biology to help you succeed, and every step forward, no matter how small, is progress.
This guide is for educational purposes only and does not replace advice from your healthcare provider. It is based on guidelines from Obesity Canada. Last updated: April 2026.
Keep Going
Learn how to eat before and after surgery, understand obesity as a chronic disease, or take the free Empowered Health Course.
Get in Touch
Questions about surgery, eligibility, or referral? Reach out, we’d love to hear from you.