Bariatric surgery FAQs


1. Does non-operative weight loss methods work?

Yes, all types of diet, exercise and non-operative temporary weight loss methods works, including the gastric balloon and endoscopic linear barrier.


However the body normal physiology, which aims to achieve homeostasis or maintains equilibrium, in this case a steady body weight, often compensates by increasing hunger and many patients will eventually regain most of the weight loss that was lost with time (months to a year). This often leads to failure of weight loss in the longer term, fluctuating body weight, a “yo-yo” weight or even worse, progressive weight gain over time, where people gain more weight than they lost over time, despite initial successful dieting attempts.


Non-operative weight loss methods has been reported to achieve roughly 5-10% total body weight but permanent weight loss is not possible with restriction of caloric intake alone. In contrast bariatric surgery (sleeve gastrectomy or gastric bypass) is reported to achieve over 50% excess weight loss over time (beyond 2 to 5 years) in over 75-80% of patients.


The ideal results would be selecting the appropriate patients for bariatric surgery, achieve over 60-70% excess weight loss in the first year or 50% excess weight loss in the longer term (remember weight regain is the norm after 1-2 years) and change eating behaviour and lifestyle for the better for the future.



2. Why is bariatric surgery necessary?

Bariatric surgery should be considered as complement to good diet and exercise, not a substitute. The differences compared to non-opertive weight loss method is that bariatric surgery, in particular the laparoscopic sleeve gastrectomy and gastric bypass, aims to achieve greater weight loss, sustained weight loss over longer periods of time, improvement in inflammatory states and (partial or complete) resolutions of medical conditions due to obesity.


For the majority of Caucasian patients with a BMI over 35 and associated medical or physical conditions, a more permanent solution is necessary to achieve not just a reduction in body weight but more importantly to halt the metabolic (chronic inflammatory) damage at a cellular level, reduce the cardio-vascular risk factors and improves medical co-morbidities, such as Type 2 diabetes, hypertension, elevated cholesterol or triglycerides, obstructive sleep apnoea, etc.


More importantly bariatric and metabolic surgery, either a sleeve gastrectomy or gastric bypass, is postulated to affect the neuro-hormonal axis, achieve satiation (neuroendocrine brake), lower the body weight set point (the new baseline), have positive incretin effects to improve Type 2 diabetes, as well as other possible mechanisms still undiscovered, which non operative weight loss methods does not offer.



3. What is the concept of metabolic surgery and body weight set point?

Normally the body become accustomed to a certain body weight set point and will always try to maintain this weight, an important homestostasis for survival, by increasing or decreasing appetite and counterbalance it with the metabolism, to achieve this steady state.


The aim of metabolic surgery is to get the body to reset to a new equilibrium at a lower body weight, so that your organ systems will try to achieve this new steady state, like a thermostat in your home where the house is constantly trying to adjust to the lower set temperature. For example instead of weighing 120kg, if the reset weight is 90kg, then the body will try to adjust the hunger, calorie intake and metabolism in order to achieve a constant body weight of 90kg.



4. What is the concept of lifestyle change or behavioural modification?

Unhealthy eating habits are a combination of large volume feeds, consisting of poor quality foods (high in calories, animal saturated fats, complex carbohydrates, sugars, salts, preservatives and chemicals) and eaten in quick time (forceful or binge eating).


Bariatric surgery assists patients to start the weight loss process, to help patients control their appetite and reduce caloric intake initially and more important is the long term, alters lifestyle and eating behaviour for the better and this is the responsibility of individual patients.


Most the weight loss occurs in the first 6 months. Beyond 1 year there will hardly be any additional weight loss. This is the time when the more important lifestyle and behaviour change needs to occur.


5. What is a poor diet or eating habit?

A poor diet or eating habit is a combination of:

  • Eating large portion food (supersized meals or second helpings).
  • Eating energy dense foods (high in fats, sugars and starch).
  • Eating processed or refined foods (which are full of chemicals and preservatives and often lacking in nutrient and vitamin).
  • Eating too quickly (forceful or binge eating behaviour). Similarly drinking excessive amounts of fluids in one attempt (eg. 650mls soft drinks) or guzzling down large volume of fluids and alcohol during meals is discouraged.
  • Eating meals at irregular times, often trying to fast or not eat during the day and binge during the evening. Often with weight loss attempts although significant weight loss can be achieved initially, the long term behaviour change is not and massive weight regain may occur, resulting in a wide fluctuating “yo-yo” weight, which in fact may be more harmful to the patient.
  • Emotional eating due to stress and anxiety.



6. What is proper eating behaviour?

Eating well is really a good eating habit. The advices are often:

  • Eat regularly 3 times a day, avoid skipping meals.
  • Good food portions without excess (especially during dinner time).
  • Good food choices and healthy meals.
  • Good eating habits (eat slowly and enjoy your meals, avoid binge eating).
  • Minimise sweet drinks (especially soft drinks and alcohol).

Remember food is not the enemy. Every one of us needs to eat a well portioned nutritious meal about three times a day, have adequate calories and proteins as well as all the recommended daily intake of vitamins and minerals.


Weight gain is excessive caloric intake, often consisting of poor quality meals and lack of physical activity. Obesity is poor eating behaviour (as described above) repeated many times and became a bad habit. Some common symptoms when patients come to see a bariatric surgeon are feeling hungry all the time, grazing through out the day or having a ravenous appetite leading to binge eating and lack of satiety after meals.


7. What should people be eating?

  • Have more vegetables, fruits, beans and nuts. These fresh foods are sometimes termed metabolic foods.
  • Have more fresh fish, chicken (preferably without the skin) and good quality cuts of meat. It is recommended that an average person have 50-60g of protein a day.
  • Good food portions, good food choices and good eating habits to avoid hunger and binge eating (over compensating).
  • Avoid sugars or artificially sweetened drinks, fruits or food.
  • Limit junk or fatty food (more home cooking or fine dining, less take away).
  • Have less starch (white bread, pasta, rice, potato).
  • Have less processed foods or food with added oil and salt.
  • Good food needs to be balanced with having a regular exercise program, to maintain a healthy basal metabolic rate.


As alluded above, weight loss tends to plateau after 1 year. Following this as the appetite suppression gets less and various environmental factors come into play (fast food, drinks, desserts, processed foods), some weight regain is inevitable.



8. What should people expect after successful bariatric surgery?

Initially in the first 12 months after a sleeve gastrectomy or gastric bypass, weight loss is very obvious with associated improvement in the physical status and resolution of some medical problems. The hunger is less and satiation is achieve early, with some patients reporting that they are not feeling hungry and sometimes even forget to eat or feeling full after small meals.


After the first year, the gastric pouch or sleeved remnant may have stretched a bit, there may be return of hunger or cravings, the ability to eat a large meal portion increased and some weight regain is expected. It is emphasized that this is the norm and expected with all types of bariatric surgery.


Beyond 2 to 5 years, the weight loss would have plateaued, the body weight fluctuation eventually will stabilize and a new set point is achieved. Hopefully the majority of patients would have managed to achieve close to 50% excess weight loss and learned the good eating habits, proper diet, nutrition and exercise balance.


9. What are the essential points to remember?

  • Bariatric surgery is only appropriate for patients who need to lose a significant amount of weight, improve the medical problems and physical status.
  • Sleeve gastrectomy and gastric bypass is sometimes considered as a metabolic surgery as well with good changes to the body’s physiology and balance (homeostasis).
  • Surgery will only work in conjunction with a permanent lifestyle and behaviour change, to achieve the best results in the long term.
  • Losing weight involves breaking bad habits or food additions to “Western diet” such as fatty meals, laden with calories, sugar and carbs. Less breakfast cereals or processed foods with added sugars and preservatives, less soft drinks (even those with artificaial sweeteners) and alcohol, which are calorie dense and may increase the addition lifestyle.
  • To help with maintaining a lower body weight set point after bariatric surgery, patients are encouraged to eat more, in particular fresh protein foods (sashimi, steamed fish, chicken or lean meat), more nuts, beans, fresh fruits and vegetables. These foods are good to improve the body metabolic rate (thermogenic effects of metabolic foods) and full of vitamins, trace minerals and anti-oxidants.
  • The other important point that is not mentioned above is that the weight loss journey is not always smooth or straightforward, the results often vary with different individuals with many factors to consider. The assistance from the local general practitioner, dietician and exercise physiologist are all very important.



The above is only a simple guide and for general information
. For any specific questions and for individual cases please consult a medical practitioner and a qualified bariatric dietician.