Bariatric surgery is one of the most effective long-term treatments for obesity. Most patients achieve significant weight loss in the first 12-18 months, however for some individuals, weight regain can occur in the years that follow. This can feel discouraging, particularly after the effort involved in surgery and recovery.

It is important to understand that weight regain is rarely about willpower. In most cases, it reflects biological adaptation, behavioural patterns and life circumstances.

What causes weight regain after bariatric surgery? 

Metabolic and Hormonal Adaptation

The body is designed to defend against weight loss. After significant weight reduction, resting metabolic rate can decrease and hunger hormones can increase. This is a normal physiological response and not a personal failure.

Procedures such as sleeve gastrectomy and gastric bypass alter gut hormones in ways that reduce appetite and improve blood sugar control, while reducing the amount of food a person can consume in one sitting. Over time, some of these effects can soften, leading to a gradual increase in hunger.

Anatomical or Medical Factors

In some cases, the stomach pouch or sleeve may stretch slightly over time. If weight regain is significant, an assessment can determine whether dietary adjustment, medication or revision surgery may be appropriate.

Weight regain after bariatric surgery is multifactorial. It is rarely due to lack of effort alone. Obesity is a chronic condition. Bariatric surgery is a powerful tool, but long-term success depends on ongoing support, monitoring and early intervention when changes occur.

If you are concerned about weight regain, early review with your team allows practical strategies to be implemented before the situation progresses further.

Weight loss injections have transformed public awareness of obesity treatment. Many patients now ask whether surgery is still necessary. Bariatric surgery still remains the most effective treatment for severe obesity. 

When Bariatric Surgery May Be More Appropriate

For people living with obesity, especially those with type 2 diabetes, high BMI or repeated cycles of weight regain, bariatric surgery continues to offer the most reliable long-term results. It is currently the only intervention with decades of data demonstrating sustained weight loss.

When Weight Loss Medication May Be Suitable

For some people, particularly those earlier in their weight journey or not ready to consider surgery, medication can be a reasonable starting point.

What Happens When Medication Stops

When a person stops taking weight loss medication, appetite signalling doesn’t return to baseline; in fact, a person often finds themselves hungrier than ever before. Without strong lifestyle strategies, increased hunger can lead to gradual weight regain and you end up back where you started or worse. 

How Bariatric Surgery Is Different

Procedures such as sleeve gastrectomy and gastric bypass alter gut hormone release and reduce ghrelin production, while reducing your stomach capacity. Weight management is not about willpower. It is about understanding physiology and choosing the approach that aligns with long-term health goals.

After bariatric surgery, every sip and bite counts. Your new stomach capacity is smaller, so the foods and drinks you choose need to be packed with nutrition, not empty calories. Milk can be a great source of protein and calcium, but not all milk is created equal. Understanding the differences can help you make choices that support your recovery and long-term health.

Comparing your options

Cow’s milk

Regular cow’s milk naturally contains protein, calcium and some natural milk sugars (lactose). Choose reduced-fat or skim milk to lower overall calories while still getting around 8 grams of protein per cup. It’s often fortified with vitamin D, which supports calcium absorption. For most bariatric patients, this remains the gold standard unless lactose intolerance or dietary preference suggests otherwise.

Lactose-free cow’s milk

If you experience bloating or discomfort from lactose, lactose-free milk can be a good alternative. It has the same nutrients and protein as regular milk, just with the lactose broken down for easier digestion.

Soy milk

Of the plant-based milks, unsweetened soy milk is the closest nutritionally to cow’s milk, offering around 7–8 grams of protein per cup. Make sure you choose one that’s unsweetened and calcium-fortified, as some flavoured or sweetened versions can contain up to 10 grams of added sugar per cup.

Almond, oat, coconut and other plant milks

These tend to be much lower in protein (often less than 1 gram per cup) and can contain added sugars to improve taste. Oat milk, for instance, is naturally higher in carbohydrates and often sweetened, making it a poor choice if you’re managing your sugar intake. Coconut milk is higher in fat and calories, with little protein benefit. If you prefer these milks, look for unsweetened and fortified versions and use them occasionally rather than as your main source of protein.

Protein-enriched or high-protein milks

Several brands now offer high-protein or “ultra-filtered” milk options. These can contain up to twice the protein of regular milk with less sugar, making them a smart choice for bariatric patients who struggle to meet daily protein goals.

A few final tips

• Always opt for unsweetened varieties – “original” or “barista” blends are often sweetened.
• Avoid milks marketed as “light” or “diet” unless you’ve checked the protein content. Some sacrifice protein for fewer calories.
• If you enjoy flavoured milk, treat it as an occasional indulgence – some contain as much sugar as a soft drink.
• If you’re struggling to meet protein goals, consider adding a spoonful of your approved protein powder to milk or a smoothie for an extra boost.

   

After bariatric surgery, your nutrition choices matter more than ever. Milk can be a valuable part of your diet, but it’s important to choose wisely. Go for options that are high in protein, low in added sugars, and enriched with calcium. Read labels carefully, and when in doubt, check with your dietitian about which milk best supports your stage of recovery.

Health, body and weight are deeply personal topics. Many people avoid talking about them – even health professionals struggle to do so well. But when someone you love is struggling with their weight, you might feel torn: you want to help, but fear causing shame, hurting the relationship, or being misunderstood. This guide is designed to help you approach the subject gently, respectfully, and in a way that builds connection rather than conflict.

Ask permission before you begin

One of the most respectful things you can do is to ask permission before raising the topic. You might say:

“Can I share something I’ve been worried about?”

“Would it be okay if I mentioned something I’ve noticed about your health?”

This simple act gives your loved one control. It signals that you respect their boundaries and it reduces the chance of defensiveness.

Share observations, not judgements

When you talk about what you’ve noticed rather than what you assume, it helps your loved one feel seen rather than attacked. For example:

“I’ve noticed you’ve been avoiding walks lately, and I wondered if your joints have been sore?”

That’s very different from: “You’ve gotten too heavy; you need to exercise.”

Describing behaviour rather than assigning blame creates space for honesty.

Listen more than you talk

Once you’ve opened the conversation, pause and give them space. You might discover things you didn’t know, such as underlying medical issues, emotional challenges, or past failed attempts at weight loss that left them disheartened. Listening shows respect and builds trust. It also helps you understand whether they want your help right now or whether they simply need to feel heard.

Offer to support, not to fix

Your role isn’t to prescribe or correct, it’s to support. You could offer to make small changes together, like cooking healthier meals, walking after dinner, or researching dietitians or support programs if they’re open to that. Statements like “We can figure this out together” or “Would you like me to help find someone you can talk to?” are far more effective than “You should…” Even if they’re not ready, knowing you’re there and non-judgmental makes a difference.

Acknowledge that change takes time

Behavioural change is rarely linear. There will be starts, stops, and moments of frustration. Be patient, especially if you’ve seen your loved one try before. The goal is not to rush them but to stay beside them.

Common fears (and how to manage them)

“They’ll feel judged or ashamed.” That’s a valid worry. This is why tone and timing are everything. Keep the conversation private, gentle and loving.

“What if they don’t want to talk?” If they say “not now,” respect that boundary. You’ve opened the door; they know they can come to you when they’re ready.

“I don’t want to make things worse.” You may stumble, but if your intent is genuine and you’re open to apologising if something lands wrong, your care will come through.

Why talking about weight the right way can help

When handled compassionately, these conversations can strengthen trust and connection, reduce feelings of isolation, encourage professional support (GP, psychologist, dietitian, or bariatric specialist), and reframe weight in terms of overall wellbeing rather than shame. Even if nothing changes straight away, showing that you care enough to have the conversation and that you’re a safe person to talk to can be life-changing.

Weight is a deeply personal subject surrounded by stigma and misunderstanding. But silence can also be isolating. When you approach the conversation with permission, empathy and respect, you send a powerful message: “I care about you, and I’m here to support your health, not to judge you.” You don’t need the perfect words; you just need kindness, patience and a willingness to listen. Over time, that can do far more than any single piece of advice.

Learning to recognise fullness after bariatric surgery is one of the most important parts of your new relationship with food. In the early weeks after surgery, your body’s hunger and fullness signals can feel unfamiliar, and that’s completely normal. With time and practice, you’ll learn to understand these new cues and respond before discomfort sets in.

Why does fullness feel different after bariatric surgery?

Your stomach is now smaller and while it empties more quickly, any food you eat will pass more slowly into the stomach; when it arrives there stomach pressure rises quickly to create “full” signals that then switch off hunger. This means it takes less food to feel satisfied, and the sensation of fullness arrives faster. Instead of the “stretched” feeling you may have noticed before surgery, fullness now tends to feel higher in the chest or throat, or as a subtle tightness beneath the sternum.

It’s also important to remember that true fullness can lag behind your last bite by a few minutes. Eating slowly gives your body time to send accurate signals to your brain.

Tips to help you recognise fullness sooner

• Put your fork down between bites. This simple act slows you down and allows signals to catch up.
• Pause mid-meal. Take a break after a few bites – you might realise you’re already satisfied.
• Avoid distractions. Turn off screens so you can pay attention to how your body feels.
• Use smaller plates and cutlery. This encourages portion control without relying on willpower.
• Reflect after eating. Ask yourself, “At what point did I feel comfortable?” Over time, this builds awareness.

Remember, fullness will evolve

As you progress through your recovery, your capacity and signals will change. Early on, fullness may come after a few spoonfuls; months later you’ll be able to enjoy small, balanced meals. The key is to always eat mindfully and stop before discomfort.

If you’re unsure whether you’re eating the right portions or recognising fullness correctly, reach out to your dietitian or bariatric team. They can help you fine-tune your portions and habits to suit your stage of recovery.

After bariatric surgery, your body needs protein to heal, maintain muscle mass and support weight loss. Many patients start with shakes and supplements in the early weeks, but over time, these shouldn’t be your main source of protein.

Protein + fibre = a powerful duo

Protein helps you feel full and preserve muscle, while fibre supports gut health, regulates digestion and keeps blood sugar steady. Combining both in your meals, for example, chicken with roasted vegetables or lentils with leafy greens, gives your body long-lasting energy and supports your recovery.

Ways to add more protein naturally:

• Include eggs, lean meats, poultry, or fish in every meal
  
• Choose dairy or dairy alternatives with higher protein content (e.g. Greek yoghurt)
  
• Add legumes such as lentils, chickpeas or beans to soups, salads, or stews
  
• Sprinkle nuts or seeds over salads, porridge or smoothies
• Use wholegrain bread or crackers with cottage cheese, tuna or boiled eggs

If you’ve had bariatric surgery, you’re already making big changes to your health. But rapid weight loss can also trigger side effects, and gallstones are one of the more common ones. While not every patient will have problems, some may need their gallbladder removed in the months or years that follow. Understanding why it happens, what to look out for, and how it’s treated could be useful for the future.

Why can gallstones develop after bariatric surgery?

Rapid weight loss after surgery changes the balance of cholesterol and bile salts in the gallbladder, making gallstones more likely to form. Eating smaller portions also means the gallbladder empties less often, giving bile more time to crystallise. In some procedures, like gastric bypass, there can also be changes to the nerve signals that control gallbladder contractions, which may further increase the risk.

How common is gallbladder removal?

While 10-20% of patients develop gallstones in the first year after bariatric surgery, only around 8% experience symptoms, and roughly 4% require gallbladder removal. The highest risk period is the first 6 – 18 months after surgery, when weight loss is at its fastest.

Recovery after gallbladder removal

Most gallbladder surgeries are performed laparoscopically, which means small incisions and a fast recovery. Patients are usually back to light activities within a week and fully recovered in two to four weeks. While the body can digest food without a gallbladder, some people may experience temporary changes in digestion. Eating smaller, more frequent meals and avoiding very high-fat foods in the early weeks can help.

Can gallstones be prevented?

Not all gallstones can be avoided, but following your bariatric team’s nutrition guidelines and staying hydrated may help. If patients are particularly worried about developing gallstones after bariatric surgery, they can ask to be prescribed a medication called ursodeoxycholic acid. This medication, which isn’t PBS subsidised, helps prevent the formation of gallstones but must be taken for 12 months or more following surgery. 

Gallbladder removal after bariatric surgery is not inevitable, but it’s worth knowing about, especially during the rapid weight loss phase. By understanding the risks, recognising symptoms early and seeking prompt medical advice, you can stay proactive in protecting your health.

So you’ve had your bariatric surgery and you’re ready to tackle your new journey ahead, lose the excess weight and make your way towards a healthier and happier life. At Upper GI Surgery we want to make this as easy for you as possible (because we know it can be tough) and like to provide useful information for our patients to help them along the way.

One of the major downfalls we see is that people aren’t actually aware of the essential nutrients in food. As a result they end up eating the wrong types of food and struggle to lose weight, or end up gaining weight further down the track. We have put together an easy guide of the essential nutrients that exist in food, to help you understand and make it easier for you to plan your meals.

Macro Nutrients

Water

About 50 per cent of the food we consume is made up of liquid. We need a minimum of one litre of water every day, but a lot of this will come from our food. People who are losing weight, people who have problems with constipation and those who are exercising will need to drink more. You need to avoid sweet and milky fluids. Most people who drink these things are not really thirsty – they are just filling in time.

Protein

Most of the protein we eat we get from meats, fish, eggs and dairy products. We absorb plant protein less efficiently than we absorb animal protein, and many supposedly high-protein plant foods contain less protein than we think. We need a minimum of 40 grams of protein per day, but it’s better to aim for 60 grams. The following calories and protein are provided by 100 grams of these foods:

Sugar: 390 calories; no protein

Cottage cheese: 100 calories; 11 grams protein

Yoghurt (Greek): 60 calories per 100 ml; 10 grams protein

Tofu: 75 calories; 8 grams protein

Baked beans: 150 calories; 6 grams protein

Bread: 290 calories (two-and-a-half slices of toast); 12 grams protein

Fibre

Deficiency in fibre is very common in patients after weight loss surgery. Unless you can get your bowels moving at least every two days you will develop debilitating and permanent constipation. Good sources of fibre include fresh fruits, vegetables and salads. Breakfast cereals with bran can be high in fibre. We recommend unprocessed bran (with breakfast cereal), or using supplements containing soluble fibre (Benefibre) or psyllium (which creates less gas) that you can put into water, such as Metamucil.

Carbohydrates

Carbohydrates are crucial for our day-to-day functioning, but they are the food group most commonly associated with the development of obesity and the recurrence of obesity after weight loss. Carbohydrates are the key ingredient in breads, snacks, potatoes, fruit juice, alcohol and sweets. Eating high GI carbohydrates or simple sugars promotes hunger, which promotes more carbohydrate eating – this includes foods like white bread, raw sugar, honey and rice malt ‘Low-carb’ versions of these foods are still just carbs. Our minimum requirement is about 50 grams of high fibre low GI carbohydrate per day which includes foods such as grainy bread, cereals and legumes. Most people should try to limit their intake to 60–100 grams per day, unless they are doing a lot of exercise. Carbohydrates are converted into sugar and eating sugar makes us produce the hormone insulin. For people needing to lose weight, their body needs to switch from using sugar as a fuel to using fat, this will occur if they limit their carbohydrate intake and start using stored fat for energy.

Folate

Folate is a vitamin found in fresh fruit, vegetables and salad. Patients who don’t get enough folate usually look and feel sickly. A daily multivitamin will provide sufficient folate for patients after surgery.

Thiamine

While present in many foods and all multivitamins, thiamine is a very important vitamin. Postoperative patients who experience vomiting and don’t take a multivitamin to supplement their thiamine levels are at very high risk of developing irreversible neurological injury and possibly dementia.

Vitamin B12

Vitamin B12 is the second most frequently deficient vitamin in Australia. It is only found in animal protein. If someone is developing a deficiency in B12, the only effective way to supplement it is via injections from your GP (every three to six months). All gastric bypass patients, many sleeve gastrectomy patients, and some lap band patients need these injections.

Iron

We get iron from meat proteins. There are small amounts in vegetable protein. Iron deficiency is quite common, and it is significant for two reasons:

• Iron deficiency can lead to a drop in blood production, which will lead to fatigue and reduced exercise capacity.
• Iron deficiency is the first sign of many bowel and stomach cancers.

Patients having gastric bypass often need iron supplements.

Other minerals: iodine, zinc, selenium, copper

In Australia our soils are deficient in iodine, so a multivitamin with iodine is advised. The other minerals are also important and a daily multivitamin will be sufficient for most patients. Patients who have diarrhoea, vomiting, poor diet, or who are considering pregnancy should probably take a multivitamin twice daily. Zinc, iron and silica may help reduce the risk of early hair loss after surgery.

At Upper GI Surgery we provide consultations with our dietician, both before and following your weight loss surgery. We believe this gives you the best chance of having the information you need in order to create a healthy balanced diet geared for weight loss.

You have probably heard the term BMI used before when relating to a person’s weight, but what is BMI?

BMI stands for Body Mass Index and is an estimation of a person’s body fat based on their height and weight. To calculate your BMI you first need to find out your weight and height, then you can enter this into our handy BMI calculator on our homepage and it will calculate your BMI. If you want to know how the calculator works:

With the metric system, the formula for BMI is weight in kilograms divided by height in meters squared.

What does this number mean?

It is important to remember that this number is simply a guide and isn’t the only factor to be taken into account when determining a healthy weight or lifestyle.

Below 18.5 – Underweight

18.5 – 24.9 – Normal Weight

25.0 – 29.9 – Overweight

30.0 – 39.9 – Obese

40.0 and Above – Morbidly Obese

As we have mentioned, your BMI gives an approximation of a person’s body fat; however other factors such as waist measurement and lifestyle need to be taken into consideration when determining whether your weight will have a negative effect on your health. For example a person’s age, race or even gender can mean BMI can be interpreted differently. A person may be very muscular resulting in a higher BMI, or body fat may be underestimated in an older person that has lost muscle mass.

My BMI says I am obese, am I eligible for weight loss surgery?

Although BMI is a useful guide for individuals and medical professionals, there are still many more considerations to be taken into account before you would be considered eligible for weight loss surgery. Again the first step to take would be to consult your GP or health professional for advice; often lifestyle changes such as improved diet and increased physical activity can result in long-term weight loss, reducing your BMI.