Obesity Management and Treatment

This page provides some information on Obesity, and how it can be managed in General Practice.  Click on any of the headings below to go to the relevant section:

Obesity and its implications
Management and Treatment of Obesity
Key steps for Obesity Treatment
Obstructive Sleep Apnoea and Anaesthesia (Surgery patients)
References
Resources

Obesity is defined as the excess accumulation of body fat, and is caused by a combination of genetic factors, inappropriate eating and reduced activity.

There may be 2 components to obesity:

1. Aetiology
   Fat is the major energy store of the body. An increase in fat stores can only occur with an increase in energy intake or a decrease in energy expenditure (although a number of factors or processes modify this simple equation).
2. Genes
   There is a genetic component to obesity - for example, the weight of adults who were adopted as children is related to that of their natural parents and not to that of their adoptive parents. The direct genetic effect on obesity is estimated to be 25-40% and consideration of indirect genetic factors raises the genetic effect to some 70% of the cause of obesity.#

How is Obesity assessed?

Obesity can be assessed by the body mass index (BMI), that is, weight in kilograms divided by the square of height in metres (click here to go to our user-friendly BMI Calculator).  The simplest and best measure of risky fat is a simple waist measurement (>88 cm for women and >102 cm for men).

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Risks Associated with Obesity

There is an increased risk of mortality, at any age, due to obesity alone. Obesity is also known to cause or contribute to many health problems, including: increased cardiovascular risk, impaired glucose tolerance and type 2 diabetes, hypertension, dyslipidaemia, sleep apnoea, non-alcoholic steatohepatitis, orthopaedic problems and polycystic ovary syndrome. (See table below on Complications of Obesity).  These risks have been proven to be significantly reduced by weight loss.

Why is obesity on the increase?

Obesity has now been classified as an epidemic, given that the number of obese adults appears to have more than doubled in Australian between 1980 to 2000*. Medical practitioners agree that the recent increase in obesity numbers is clearly due to the continuous availability of high-energy foods (such as 'fast food'), together with a major reduction in physical activity.*

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While management is difficult, it is possible and can be effective so long as appropriate goals are set. Treatment of obesity also has to be long term due to genetic predisposition, and the current environment (abundant food widely available, and a tendency for much less activity in daily living).

All treatment strategies involve lifestyle modification, with a reduction of energy intake (generally, a low fat diet and an increase in physical activity, and including, where appropriate, pharmacotherapy. Behaviour modification, with input from a dietician, helps both initial weight loss and maintenance.

Treatment of obesity is critical as there is a significant reduction of associated health problems once weight loss is achieved.#

The aim and benefits of treatment

The aim of treatment is not to achieve ideal weight, but is rather to reduce risk factors by a smaller, achievable loss.  Importantly, a weight loss of 5-10% is associated with useful changes such as:

• 5-10% lowering of blood pressure,
• 5% reduction in total cholesterol, and 10% reduction in triglycerides,
• 10-15% increase in HDL cholesterol, and
• Significant improvement in glycaemia control.

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The importance of goal-setting

From the outset of treatment, there are many other goals which could and should be set, including

• better mobility,
• lower risk factors,
• control of metabolic disease (non-insulin dependent diabetes mellitus, dyslipidaemia, hypertension),
• less medication and
• increased well-being.

Of course, there are often individual goals that a patient desires or needs, and they can be achieved with the ongoing support of a doctor (and other allied health professionals, where appropriate).

Our brief summary below provides 4 steps for the long-term treatment of overweight and obesity.  It is important to note that doctors recommend an initial intensive treatment phase (weeks to months) and then continuing follow-up and treatment (years) , in order to sustain a healthy weight loss, and to improve quality of life.

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Step 1 - Diagnosis

Patients need to meet with their doctor to discuss their history, have an examination, and investigate treatment for obesity, and to manage related health problems.

Step 2 - Weight Loss

A.  Lifestyle Modification (to decrease energy intake and increase physical activity):

• It is important that patients are ready and enthusiastic about attempting weight loss and set realistic goals,
• A negative energy balance must be established, by reducing energy intake and increasing energy expenditure,

B.  Diet:

• Low-fat, reduced-carbohydrate diet.  A reduction of 2500 kJ or 600 calories from the patient's normal food intake is generally prescribed (this should lead to weight loss of 0.6 kg per week).
• Calorie intake can be calculated using a diet diary, which can be commenced over a week before starting weight-loss treatment.  The advice of a trained nutritionist or dietitian will also be very useful.
• Limit fat intake and carbohydrates, especially those with a high glycaemic index (GI), which means rapidly digested and absorbed carbohydrates, because high insulin levels can encourage weight gain.
• Very low energy diet (VLED) (commercial, over-the-counter mixture of essential nutrients with defined energy content, usually supplied as a powder to be mixed with water and drunk three times daily),
• Meal replacement programs can be used to encourage weight loss - eg, commercial program that provides pre-prepared meals, or meal replacement shakes/drinks; and
• Commercial weight loss centres can provide an excellent .

C.  Physical Activity:

• As a start, patients should try to undertake 30 minutes of low to medium-intensity aerobic activity for 3-5 days a week, gradually building up to 80 minutes of moderate-intensity activity per day.
• Walking is one of the best forms of exercise - only a few minutes walking may be possible at first, but both the duration and intensity may be increased as the program proceeds and the patient loses weight.
• If a patient has difficulty because of arthritis, hydrotherapy (activity in water) may be of great benefit, and will help to get them get started.
• Walking for 30 minutes is OK - It is not necessary to walk for an extended period of time.
• The overall aim is to increase in the activities of daily living and variety in the activities undertaken.
• Creative Alternatives - where possible, a patient should choose an active alternative such as walking up stairs (rather than taking the lift or escalator), walking/cycling to work (instead of driving), and making small changes, such as getting up to change television channels.
• This increased activity will equal increased daily energy expenditure.
• For more information on exercise, please visit

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Step 5: Weight maintenance (lifelong)

• Lifestyle modification - maintaining a healthy diet (low-fat and low-carbohydrate), supplemented with a high level of physical activity.  This will also have broader benefits on well-being, including improved cardiovascular fitness.
• Cessation of smoking is also a critical aspect of lifestyle change - please visit Quit for more information - www.quit.org.au
• Pharmacotherapy (if required).

Step 4: Obesity / Bariatric surgery

Used for morbidly obese patients who have repeatedly failed medical therapy.

The surgery involves the suturing of an adjustable band around the very upper stomach. The restriction on the stomach can be modified by adding or removing saline from a reservoir on the rectus sheath (which can be performed periodically in the GP's office).  This type of surgery is the most effective long-term treatment for those with class III obesity.

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Patients with sleep apnoea (either obstructive sleep apnoea (OSA), central, or mixed sleep apnoea) require special care to be exercised when undergoing surgery that requires an anaesthetic. 

Airway maintenance issues and frequently associated cardiopulmonary abnormalities place OSA patients at risk for perioperative complications.

By ensuring thorough pre-operative assessment, a thoughtful and well-executed aesthetic plan, and vigilance which extends well into the postoperative period, practitioners can ensure safe anaesthesia for these patients.+

Pre-operative Assessment

• It is recommended that a thorough history and physical examination is undertaken in order to ascertain if the patient has Sleep Apnoea.  Physicians may refer to our OSA Criteria page as a resource - Click Here.
• Once the presence of sleep apnoea is suspected, the anaesthesiologist should determine if the patient has had a previous sleep study and, if so, review the results. If no sleep study has ever been conducted (or if a sleep study was done before significant weight gain or a similar potentially associated factor), a sleep study may be recommended.
• Further, the severity of OSA may be established by questioning the patient regarding the degree of night-time sleep disruption and daytime sleepiness (although patients are often unaware of their sleepiness or the extent of their night-time disruption, in which case, it may be beneficial to speak with their partner to ascertain witnesses apnoeas).

The importance of Continuous Positive Airways Pressure (CPAP)

Clinical experience confirms that anaesthesia can be problematic in OSA patients:

• OSA is characterized by repetitive episodes of upper airway obstruction during sleep - may be accompanied by sleep disruption and arterial oxygen desaturation.
• General anaesthesia suppresses upper airway muscle activity, and thereby impairing breathing by allowing the airway to close.
• Anaesthesia may increase the number of, and the duration of sleep apnoea episodes with a resultant drop in arterial oxygen saturation, and will inhibit the arousal mechanism which would naturally occur during unanaesthetised sleep.
• The period of awakening from anaesthesia after surgery can be problematic for OSA patients - lingering sedative and respiratory depressant effects of the anaesthetic (as well as post-operative narcotics use) suppress the upper airway muscle activity.
• During this period CPAP must be used and appropriate monitoring of oxygenation, ventilation, and cardiac rhythm should be employed.  Click Here to go to our Treatment of OSA information page, which explains how CPAP works.

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References

* Joseph Proietto and Louise A Baur "Obesity Management" MJA 2004; 180 (9): 474-480;

# Ian D. Caterson ""Obesity and Its Management" Aust Prescr 1999;22:12-16.

+ Ogan O. U, Plevak D. J. “Anesthesia safety is always an issue with obstructive sleep apnea” Anesthesia Patient Safety Foundation Newsletter 1997:12:14-15

Obesity Management in Adults:

• For Patients - make an appointment to see your doctor to discuss your concerns and to plan a successful obesity management program
• For General Practitioners - click here to download the NHMRC's Guidelines for Management of Obesity by GPs
• For All Doctors - click here to download the NHMRC's Clinical Practice Guidelines for Management of Obesity

Obesity Management in Children:

• For General Practitioners- click here to download the NHMRC's Guidelines for Management of Obesity in Children by GPs

Links to relevant websites

• Click Here to go to our Useful Links page

*Please Note: This information is intended to be used as a guide only and is not an authoritative statement. Please consult your family doctor or sleep  physician if you have further questions relating to the information provided here.

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