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.

If you are considering bariatric surgery it is important to first discuss this with your doctor and/or specialist so they can provide you with guidance on the best treatment for your individual circumstance. In the meantime we have listed some basic benefits and drawbacks of the different weight loss surgery options offered here at Upper GI Surgery.

As with any major surgery your individual circumstances needs to be taken into consideration, these are discussed during your specialist consultations and interactions with our team. If you would like more information on any of these surgery options, or would like to discuss whether you are eligible for weight loss surgery, please contact us and we would be happy to discuss this further with you.

Weight loss surgery is major surgery requiring a general anaesthetic, therefore it carries a risk of complications. If you are considering weight loss surgery and want to be more aware of the potential risks involved, then this is the article for you. We have categorised the risks into 5 categories:

Anaesthetic Risks

Anaesthesia is very safe in Australia. Despite people’s fears, patients do not die on the operating table, except in extremely unusual circumstances. The risk is so low it is very hard to measure, but is about 1 in 40,000 operations.

General Risks

There are always risks involved during and after surgery, please see below:

• Operations involve incisions, which may become infected or heal poorly.
• Hernias and other wound complications are the most common problems after gastric surgery.
• Operations also involve changes in bodily functions that put people at risk of chest infections (pneumonia), urine infections and blood clots.

These are the risks that pose the greatest threat to life after major surgery. There is also a risk of bleeding during the operation or immediately following it, so occasionally patients may require blood transfusions or even re-operation.

Death

Just as driving to work involves the remote risk of a fatal car accident, any operation carries a small risk. Most people decide to undergo an operation with this expectation and accept the possibility that things may not go as planned. The risks depend on the type of surgery you are having and your age, weight and health, so your overall risk of death may vary from one in 200 to one in 3000.

Disability

While recovering from an operation a person is, in effect, disabled. If they have complications the duration of their disability can be prolonged. Some disabilities may be permanent and some permanent disabilities occur even if no obvious complications have arisen. This is because the effects of any operation vary from person to person. As these operations affect the way your body functions, if a complication affects your quality of life it may be difficult to remedy.

Disability may take the form of prolonged tiredness, abdominal pain, difficulty eating, vomiting, or nutritional deficiencies. Most of the operations for obesity are to some extent reversible or modifiable, but attempting to fix or reverse the operation may not fix an established problem. What makes these risks acceptable is the fact that obesity causes disability, psychological distress and risk to life.

If you are considering weight loss surgery as an option and would like to discuss your personal potential risks, please book an appointment online or call our clinic to have a consultation with one of our specialists who will be able to give you more information relating to you specifically. You can call us on 02 9553 1120 or use the Hotdoc link. 

We are often asked if somebody is too young or too old for bariatric surgery because of concerns about fairly major surgery for themselves or their family members if they are they are below 20 or above age 65. When somebody presents with obesity at the extremes of age it is very important to individualise their care and make very considered decisions.  Below we will discuss some of the issues we examine while making management decisions for these patients. 

Bariatric Surgery for patients under the age of 20

There are very few topics that create more controversy than the prospect of bariatric surgery in young people.  In general, in order to make decisions easier, we break young people into 3 different groups because each of these groups has their own issues. 

Younger patients do need to be aware of the requirement for longer-term follow-up especially to reduce the risks of weight regain which would clearly be a disappointment for anyone but especially so in a younger person.  

The teenage years are tough on all of us and they are especially tough on very overweight kids who feel discrimination and social isolation far more acutely than adults do because they haven’t yet developed the life skills to manage themselves in difficult social circumstances.  While the number of people in this situation is thankfully small it is very good to know that the published results from this type of surgery are very good as long as the individual is appropriately supported by a range of specialists before and after the procedure including paediatricians, endocrinologists, psychologists and dietitians.  In general patients of this age having surgery should be under the care of a paediatrician before considering this option.

Group 3 – Childhood obesity surgery 

It seems that there is nothing media likes more than the spectre of children having obesity surgery.  This type of option is very uncommonly considered and only as part of a multidisciplinary specialist management plan.  The rare children who do end up being considered for this surgery usually have marked biologically based abnormalities in their growth, sometimes with genetic conditions that predispose them to obesity.  While the numbers of surgery in this age group worldwide are very low the results once again seem sufficiently safe to be a valid option for this rare group of patients. 

Safety of Bariatric Surgery for older patients

There are always concerns about medical fitness for surgery in people over the age of 65.  Cardiology and lung assessments will usually determine if an individual is a high risk or not. 

Putting things in perspective our weight loss operations are less likely to lead to a complication leading to either death or a major injury than knee or hip replacement, hysterectomy or other reasonably routine procedures such as angiography.  Because weight loss surgery is elective surgery, we are able to take the time to identify and correct any risk factors that might be at increased risk of harm in somebody having surgery.   

At St George Hospital we’ve looked at the safety profile of over 400 patients who have had bariatric surgery aged over 65 and haven’t had an increase in complication or re-admission compared with the younger patients.   

The weight loss goals we have for older patients are a little different than younger patients, in this group we are not aiming to get people down to an ideal body weight of BMI 25 but prefer them to get down closer to a BMI of 30 so they have a couple of extra kilograms in reserve.  There is a concern that excessive weight loss in older people can lead to loss of bone and muscle tissue which is very important for maintaining mobility, day-to-day activities and immunity. 

Surgery between the ages of 65 and 70 is reasonably common however it is uncommon for patients over the age of 70 to consider this as an option however there is no doubt that the rare individual may consider this as a reasonable option even out up to the age of 80. 

Weight loss and metabolic surgery in younger and older Australians are appropriately less commonly performed than in patients in the middle years of their life.  By carefully selecting patients who are heavy enough to benefit but well enough and supported enough to have the procedure safely we can ensure that benefits from surgery outweigh any risks. 

A question we are often asked by our patients is whether or not they need to go on a diet before they have bariatric surgery. So today we thought we would explain the pre-surgery diet that we recommend to our patients and why. 

Why do I need a special diet pre-bariatric surgery? 

Although bariatric surgery is a very safe procedure, it is still major surgery and with all surgery, there are risks involved. The pre-bariatric surgery diet is designed to assist in making your surgery as safe as possible by increasing the amount of space in your abdomen to allow easier laparoscopic surgery.

When someone goes on a high protein Very Low Energy Diet (VLED) ½ the weight they lose comes from their abdomen. A 6kg weight loss will lead to an increase of 3 litres of intra-abdominal space for surgery to occur for example. This leads to less pain and faster recovery for you as internal cuts and bruising is less.

Other benefits;

1. Patients with bad diabetes will get a reduction in their blood sugars which significantly reduces their risk of post-operative infections.
2. Patients with sleep apnoea will reduce their risk of post-op breathing complications by over 50%
3. Weight loss improves overall immunity
4. Weight loss softens the abdominal wall, so if other issues such as hernias are found during surgery, they can be fixed without needing further surgery down the track.
5. This diet allows people to try different formulations of VLED that they can use for the post-op diet.

How much weight someone “needs” to lose before surgery is different from person to person, however for many, 2 weeks on a VLED pre-op is sufficient to do the job. This equates to 4-8 kg for most people.

Special Cases

People with a BMI over 50 or weighing over 160-200 kg, those with significant and poorly controlled medical problems, and people who have had complex abdominal surgery before may need to lose a greater amount of weight before they can safely have surgery. In these circumstances we may set a specific weight target before surgery, with a plan to delay the procedure until the goals are met.

These goals may include, for example, achieving a 10% bodyweight reduction or getting to a certain nominated weight. In these circumstances the pre-op diet may need to be extended out to 4-12 weeks, depending on the goal.

What is the pre-bariatric surgery diet? 

Our patients are asked to follow an intensive phase of VLED (very-low-energy-diet) or VLCD (very-low-calorie-diet), of three meal replacements and two cups of vegetables (sometimes an additional protein serve to ensure protein requirements are met if BMI is too high) for 2 weeks. Additional fibre and plenty of water are also advised during this VLED period. 

The meal replacement that we often recommend to our patients is Optifast. It is a low carbohydrate, total diet replacement consisting of three Optifast products (meal replacement shakes or bars) that total 600-800 calories per day. Another really good product that we also recommend is Formulite, however any commercially available VLED will be OK as long as it has the protein and nutrients you need.

This diet puts patients into mild ketosis to help them lose weight rapidly, yet safely (on average 1.5 – 2.5kg per week). The low-carb nature is critical to success. Being in Ketosis forces us to burn glycogen and fat, but also suppresses hunger. Most other low energy diets promote hunger which isn’t very tolerated by most of us for more than a day or two.

It is important before you start on any diet to ensure that you have the approval of your doctor or dietitian, to avoid any nutritional deficits and to make sure you are losing weight safely. 

Pre-op Diet Troubleshooting.

VLED’s or “diet shakes” are formulated foods. This means they have a number of natural and synthetic ingredients, and not everyone tolerates them or likes the flavours. It’s worthwhile for people to try different varieties before committing to the diet, not just to make the pre-op diet easier but also to make the post-op diet easier as well.

Common issues include

1. Lactose intolerance which leads to wind and diarrhea in some people. There are lactose-free variants available (Tony Ferguson and some Vegan Shakes) however Lacteze tablets taken with the VLED will sort out most symptoms.
2. Optifast Bars are an alternate for people who want a solid VLED or are lactose intolerant.
3. Soy intolerance and artificial sweetener intolerance is an issue for some patients, in which case an individualised pre-op high-protein and low carb diet can be worked out with our dietician.
4. Headaches/crankiness/hunger. The most difficult time of the diet is the first 24-48 hours when ketosis is “switching on”. Taking regular Panadol and avoiding stressful work over this time will help.

If you are considering bariatric surgery and would like to know more then contact our practice on (02) 9553 1120 or you can

Book an appointment online