Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults ppt

ENDORSED 18 SEPTEMBER 2003
Clinical Practice Guidelines for the Management
of Overweight and Obesity in Adults
© Commonwealth of Australia 2003
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Disclaimer
This document is a general guide to appropriate practice, to be followed only subject to the clinician’s
judgement in each individual case.
The guidelines are designed to provide information to assist decision-making and are based on the best
information available at the date of compilation.
It is planned to review this Guideline in 2006. For further information regarding the status of this
document, please refer to the NHMRC web address:
For copies of this document contact:
Phone: 1800 020 103 extension 8654 (toll free number)
Email:
Website: www.obesityguidelines.gov.au
C O N T E N T S
Preface vii

Summary ix
Evidence-based statements and recommendations xv
1 Setting the scene 1
1.1 The obesity epidemic 1
1.2 The health burden 2
1.3 The nancial burden 7
1.4 The benets of weight loss 7
1.5 Possible detrimental effects of weight loss 8
1.6 Normal regulation of body weight 8
1.7 Abnormal regulation of body weight and the 10
aetiology of obesity
1.8 At-risk groups 11
1.9 Obesity and eating disorders 12
2 Assessment 21
2.1 How is energy balance disturbed? 21
2.2 Why is energy balance disturbed? 22
2.3 Other considerations 31
3 Measuring overweight and obesity 43
3.1 'Gold standard' measures 43
3.2 Anthropometric measures 44
4 Treatment: general 53
4.1 A global approach to treatment and prevention 53
4.2 A treatment model 54
4.3 Treatment expectations 55
4.4 Treatment goals 56
4.5 Treatment duration 58
4.6 Treatment providers 58
4.7 Treatment emphasis 59
4.8 Selection of patients for treatment 60
4.9 The quality of obesity treatment studies 60

CONTENTS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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CONTENTS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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CONTENTS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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5 Treatment: energy intake 65
5.1 Existing evidence of the effectiveness of diet therapy 66
5.2 Recent evidence on dietary therapy 67
5.3 Types of dietary approaches 67
5.4 Summary 80
5.5 Gaps in knowledge 80
6 Treatment: physical activity 91
6.1 Secular changes in obesity and physical activity 92
6.2 Recent ndings on physical activity 94
6.3 Summary 109
6.4 Gaps in knowledge 109
7 Treatment: behavioural therapy 119
7.1 Approaches to behavioural therapy 119
7.2 Behavioural treatment outcomes 121
7.3 Behavioural-drug combination therapy 129
7.4 Other psychological factors 129
7.5 Gaps in knowledge 131
8 Treatment: pharmacotherapy 137
8.1 Who should be treated with pharmacotherapy? 139
8.2 Pharmacotherapy treatment options 139
8.3 Drugs that inhibit nutrient absorption 145

8.4 Combined drug therapy 148
8.5 Potential new compounds 148
8.6 The ability of drugs to sustain weight loss 149
8.7 Cost-effectiveness of weight-loss drugs 150
8.8 Summary 150
8.9 Gaps in knowledge 151
9 Treatment: surgery 157
9.1 Who should be treated with surgery? 157
9.2 The effectiveness of bariatric surgery 158
9.3 Types of procedures 158
9.4 Benets of surgical intervention 168
9.5 Risks of surgical intervention 169
9.6 Summary 170
9.7 Gaps in knowledge 170
10 Weight-loss supplements and alternative treatments 177
10.1 Weight-loss supplements 177
10.2 Commercial weight-loss programs 188
10.3 Gaps in knowledge 188

CONTENTS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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CONTENTS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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Appendix A The guideline-development methodology 197
Appendix B Diet therapy evidence (1997-2001) 206
Appendix C Physical activity evidence (1996-2001) 220
Appendix D Behavioural therapy evidence 228
Appendix E Sibutramine therapy evidence 234

Appendix F Orlistat therapy evidence 238
Appendix G Surgical treatment evidence 246
Appendix H Sources for appendixes 258
PREFACE
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
vii
P R E FA C E
In recent decades the number of Australians who are overweight or obese has
continued to increase: in 1999-2000 an estimated 67 per cent of adult males and
52 per cent of adult females were classied as overweight or obese. In 1992-93,
it was estimated that obesity was costing Australia $840 million a year, of which
about 63 per cent was being directly borne by the health care system.
In 1997 the National Health and Medical Research Council’s Expert Panel on
Prevention of Obesity and Overweight prepared Acting on Australia’s Weight: a
strategic plan for the prevention of overweight and obesity. The primary outcomes
of that plan were the goals to ‘prevent further weight gain in adults and eventually
reduce the proportion of the adult population that is overweight or obese; and to
ensure healthy growth of children’.
Undoubtedly, most of the work required to tackle overweight and obesity in
Australia will take the form of population-wide strategies seeking to modify the
‘obesogenic’ modern social environment. However, during the development of Acting
on Australia’s Weight and the subsequent strategy, the need for clinical practice
guidelines for the management of overweight and obesity in Australian adults and
children became apparent. So, in 2000, in collaboration with the Population Health
Division of the Commonwealth Department of Health and Ageing, the NHMRC
initiated the development of the guidelines.
In working on the project, and having determined that separate guidelines were
required for adults and for children and adolescents, the NHMRC researched
practices for managing overweight and obesity and ensured that the practices
identied were multi-faceted—for example, strategies that span physical activity,

diet and self-esteem.
These guidelines for adults are the result of a comprehensive assessment of the
current scientic evidence. They provide detailed evidence-based guidance for
assessing and managing overweight and obesity in Australia. They also highlight
important health concerns associated with overweight and obesity and, through the
provision of clinical practice information for at-risk groups, aim to improve health
outcomes for people with conditions such as diabetes, cardiovascular disease and
some cancers. The evidence has been reviewed in detail up to January 2002. After
review of the document by stakeholders, only key additional references to March
2003 have been added, in order to expedite the process of publication.
The guidelines focus primarily on the majority population in Australia. It should be
recognised that the problem among specic groups, and Aboriginal and Torres Strait
Islander peoples in particular, has distinct characteristics that are currently less well
understood and need urgent, detailed examination.
The guidelines are designed for use by general practitioners and allied health
professionals when providing advice to patients in the clinical setting. Information for
consumers is also being developed. It is stressed that the guidelines are for clinical
practice. They do not represent a comprehensive population-based approach to
overweight and obesity in adults: that was the task of Acting on Australia’s Weight,
and it will be addressed again in future NHMRC publications.
It is recommended that these guidelines be updated and revised by 2006.
PREFACE
Clinical Practice Guidelines for Management of Overweight and Obesity in Adults
viii
S U M M A RY
B ACK G RO U N D
Overweight and obesity are in epidemic proportions throughout Australia: it is
estimated that 67 per cent of adult males and 52 per cent of adult females were
overweight or obese in 1999-2000. The gures are even higher for some ethnic
and age groups.

This epidemic of overweight and obesity is part of a worldwide trend, and it is
contributing to increasing levels of non-communicable metabolic and mechanically
induced disorders such as diabetes, cardiovascular disease, joint problems,
obstructive sleep apnoea, and some cancers.
While the causes of the problem are diverse, it is the interaction between humans’
varying levels of genetic, cultural and socio-economic predisposition to weight
gain, and an increasingly ‘obesogenic’ modern environment, that is propelling the
epidemic and explains the inter-individual differences in response.
A SS E S S ME N T
As well as the assessment of weight related co-morbidities (such as dislipidaemia,
hypertension and hyperglycaemia), clinical assessment of overweight and obesity
requires two other important aspects: examining energy intake and physical activity
levels to assess how energy imbalance has occurred; and considering the nature
of the environment, personal reasons and other factors to understand why it has
occurred.
Clinicians should take into account a person’s weight history, background, family,
work and social environments, the presence of medical co-morbidities, motivation
and readiness to change, and the costs and benets of weight loss before prescribing
any treatment.
M EA S U R EM E N T
There are no perfect measures of overweight and obesity in the clinical situation.
The most useful absolute indicator of risk and relative change is a combination
of anthropometric measures such as body mass index (BMI) or weight and waist
circumference.
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SUMMARY
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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T RE AT ME N T: G E NE RA L
Obesity is a chronic problem. There is no single, effective treatment for all
overweight and obese people, and the problem tends to recur after weight loss.
Some treatments (such as surgery) may be more effective than others in terms
of total weight loss in certain circumstances.
People’s expectations of weight loss often exceed the capabilities of available
programs, making successful treatment more difcult. However, weight loss has a
strongly benecial effect on the co-morbidities of obesity, with the degree of benet
usually related to the amount of weight loss. Even a modest loss of 5 to 10 per cent
of starting weight can result in signicant health benets.
All successful treatments involve some form of lifestyle change affecting energy
intake (food) or energy expenditure (physical activity), or both. Among the aids to
treatment are behaviour modication, some medications, low-energy or very low
energy diets, and surgery.
Treatment can be considered in a step-wise fashion, as shown in the following gure.
The bottom steps suggest that that the clinical role must be supported by public
health measures for an integrated approach to the problem.
A stepped model for clinical management of overweight and obesity
Source: Reproduced with permission—reference 10, Chapter 4.
Individual education and skills training
Behaviour modication
Medical surgical Rx
Population education and awareness raisingGeneral population
Overweight/obese
Overweight/obese
(with disordered eating patterns or cognitions)
Obese or overweight with risk factors

(BMI >30 or BMI >27 with risk factors)
InterventionTarget population
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T RE AT ME N T: E N ER GY I N TA K E
The effectiveness of any diet depends on the energy imbalance produced by a
reduction in energy intake in relation to energy expenditure. This can be done in
many ways, but some methods are more effective and have less deleterious effects
than others.
A variety of diets involving a reduction in energy intake lead to short-term weight
loss. The current evidence base indicates that low-fat ad libitum eating plans,
resulting in a daily energy reduction of 2 to 4 megajoules a day, in combination with
increased physical activity, appear to be the most effective for long-term weight loss.
It is possible that the primary mechanism through which low-fat diets exert their
inuence is reduction of energy density. Other forms of low-energy density diets
are being researched and may prove equally effective. However, the evidence
is not currently available.
Low-energy (that is, 4 to 5 megajoules a day) and very low energy (1.7 to 3.3 megajoules
a day) formula diets can lead to signicant weight loss in the short term in motivated
people under strict supervision. In the long term (say, ve years), however, they
result in no greater weight losses than an ad libitum low-fat eating plan.
T RE AT ME N T: E N ER GY E X PE ND I T U RE
It is more difcult to cause an energy imbalance leading to short-term weight loss
through physical activity than it is through dietary restriction. A regular pattern
of physical activity is, however, one of the key factors involved in long-term
maintenance of weight loss.

Lifestyle-based changes that increase the volume of physical activity (where
volume = frequency x duration x time) signicantly above the baseline level
are likely to be best for long-term weight loss.
Regular, weight-bearing exercise (for example, walking) that the person enjoys
is most effective for weight loss. A non-weight bearing form of activity (such as
swimming, walking in water or cycling) may, however, be best for very immobile,
obese patients until their level of tness increases and weight-bearing activities
can be more easily carried out.
T RE AT ME N T: B E HAV I O UR A L TR E ATM EN T S
Behavioural therapy can increase the effectiveness of other weight-loss treatments,
and the duration of the therapy inuences the ability to maintain the weight loss.
No single behavioural therapy strategy appears to be superior for long-term
weight loss.
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T RE AT ME N T: P H AR MACOT HE R A P Y
There are currently four prescription medications that have been approved by the
Therapeutic Goods Administration for use in Australia—phentermine, diethylpropion,
orlistat and sibutramine—and may offer benets as adjunct therapy for weight loss in
people with a BMI greater than 30 or greater than 27 with co-morbidities. Of these,
phentermine and diethylpropion are indicated only for short-term use.
Some antidepressant medications help some people lose weight.
T RE AT ME N T: S U RG ERY
Surgery—mainly of the types that restrict the intake or absorption of food—is the
most effective weight-loss treatment in severely obese patients. In general, surgery
is indicated for patients with a BMI greater than 40 or with a BMI greater than

35 and serious medical co-morbidities, although it is increasingly being used
in patients with BMIs lower than this.
Surgically induced weight loss results in a marked reduction in some of the
co-morbidities associated with obesity (particularly diabetes) and an improvement
in quality of life.
Although it may appear expensive relative to other treatments, obesity surgery
is one of the most cost-effective treatments available.
A LT ER NAT I VE T R EAT M EN TS
At present no herbal or other over-the-counter supplements demonstrate sufcient
evidence of long-term weight loss and lack of signicant side effects.
D EA L I N G W I T H C O - MO RB I D I TI ES
The severity of a co-morbidity will determine the type of treatment, but weight loss
should nevertheless be a primary consideration when dealing with all co-morbidities
related to obesity.
In cases of moderately elevated risk factors (such as raised blood sugars or
cholesterol), attempts should be made to manage weight through lifestyle change
before resorting to more intensive treatments.
S UM M A RY O F T R E AT M E N TS
The following table summarises the effect of weight-loss treatments in overweight or
obese adults.
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The effects of weight-loss treatments in overweight or obese adults: a summary
Treatment Weight loss/gain (kg) Weight loss/gain (kg) Ability to prevent regain?
over 1-2 years
a

over >2 years
a

No treatment
b
-0.2 +1.9 over 3-6 years No
Diet
Ad lib low-fat diet -3.9 (-2.3 to -6.1) -2.7 (-3.6 to -1.8) over 3-6 years Yes, to some degree
-4.4%
Low-energy diet -6.7 (-12.2 to +0.4) -1.1 (-4.1 to +2.7) over 4-5 years No
-6.9%
Very low energy diet -16.3 (-8.6 to 25.6)
c
-4.1 (-7.9 to +1.0) over 3-5 years Yes, to some degree in
-14.7%
c
some individuals if
-4.2 (-8.6 to +0.5)
d
combined with a lifestyle-
-4.0%
d
modication program
-11.8 (-9.2 to -14.2)
e
-11.0%
e

Meal replacement

-5.5 (-3.0 to -7.7) -6.5 (-4.2 to -9.5) over 4-5 years Yes, based on limited
-6.0% evidence
Low-glycaemic index, Not known Not known Not known
high-protein or high-
mono-unsaturated
fatty acid diets
Physical activity -1.8 (-5.8 to +0.7) -1.3 (-3.1 to +1.0) over 2-6 years Yes, if 80 minutes or more
-2.1%
f
of daily activity
Diet plus activity -7.5 (-15.2 to -4.2) -3.1 (-9.9 to 0) over 2-6 years Yes, to some degree
-8.1%
Behaviour -4.7 (-12.9 to -0.2) -2.8 (-9.6 to-0.2) over 3-5 years Yes, to some degree
-5.1%
Pharmacological
Diethylpropion -6.5 (-1.9 to -13.1) Not known Yes, while drug is taken
Phentermine -6.3 (-3.6 to -8.8) Not known Yes, while drug is taken
Sibutramine -5.6 (-7.9 to -3.8) Not known Yes, while drug is taken
6.0%
Sibutramine plus -10.8 (-16.6 to -5.2) Not known Yes, while drug is taken
lifestyle modication 10.7%
Orlistat plus a mildly -8.4 (-13.1 to -6.2)
g
-6.9
h
Yes, while drug is taken
hypocaloric diet -8.6% with a normal energy diet
Surgery
Gastric bypass -46 (-53 to -35) -42 (-62 to -29) over 3-14 years Yes
-36%

Biliopancreatic bypass -53 (-62 to -42) -54 (-84 to -37) over 3-8 years Yes
-38%
Non-adjustable -41 (-63 to -25) -25 (-39 to -17) over 3-8 years Some weight regain
gastroplasty -32%
Adjustable gastric -31 (-46 to -22) -34 (-43 to -28) over 3-4 years Yes
banding -24%
a. Results expressed as mean weight loss, with range of weight loss in parentheses and % weight loss in italics.
b. Based on the placebo arms of 31 treatment studies lasting 1-2 years and 8 studies lasting more than 2 years.
c. After 4-20 weeks.
d. After 1-2 years without diet or behavioural therapy.
e. After 1-2 years with diet or behavioural therapy.
f. With 3-5 hours of moderate or vigorous activity per week.
g. Weight loss due to orlistat alone is 2.8 kilograms.
h. Not yet published in peer-reviewed literature (abstract only)
Note:
Most treatment studies have been carried out on people of European descent, predominantly female. Many
obesity treatment studies report high attrition rates (see Appendixes B to G). These high attrition rates are
not associated with any particular intervention. They diminish the effectiveness of weight-reduction programs
and suggest caution in the interpretation of data based on the weight losses of people who remain in the
programs.
Source:
Randomised controlled trials reported in the literature cited throughout this publication.
EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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E V I D E N C E - B A S E D S TAT E M E N T S A N D
R E C O M M E N DAT I O N S
The information in this publication is summarised in two formats, as shown in
Appendix A. The evidence-based statements are founded on the levels of evidence
for clinical interventions set by the National Health and Medical Research Council.

The grades of recommendation are less formally determined, being based on
previous guidelines.
B AC K G RO UN D
Overweight and obesity are becoming an increasingly serious problem in Australia,
causing more and more, and graver, ill-health. This is part of a worldwide trend
towards obesity, and it is associated with modernisation and changing lifestyles.

Evidence-based statements Evidence level
Overweight and obesity are present in epidemic proportions throughout III-2
Australia: it is estimated that over 67 per cent of adult males and
52 per cent of adult females were overweight or obese in 1999–2000
Overweight poses a health burden at all ages, being associated with a III-2
number of diseases caused by metabolic complications or the excess
weight itself, or both.
A modest weight loss of 5 to 10 per cent of starting body weight III-2
is sufficient to achieve clinically relevant health benefits.
A SS E S S ME N T
Clinical assessment involves two aspects: examining energy intake and expenditure
to determine how energy imbalance has occurred; and considering the nature of
the environment and personal and other factors to understand why it has occurred.
Factors such as a person’s motivation, co-morbidities, and the costs and benets of
weight loss also need to be considered.
Evidence-based statement Evidence level
Food intake and levels of physical activity can be estimated only III-2
approximately in a clinical setting.
Recommendation: level B
• Although it may be necessary to evaluate food intake and energy expenditure in the
clinical situation, the currently available measures should be interpreted with caution.
EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults

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EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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Evidence level
The modern environment is a potent stimulus for obesity. III-2
Some rare cases of single-gene mutations cause severe obesity III-2
disorders, which are usually manifest early in life.
Recommendations: level B
• Before initiating treatment, known single-gene mutations should be considered
in early-onset cases of severe obesity.
• When single-gene mutation obesity is confirmed, the patient should be referred
to a specialist who deals with these problems.
Statement
In general, cases of severe obesity are more likely to have Expert opinion
basis than cases of overweight, which may result from
environmental influences alone.
Recommendations: level D
• A different, more intensive care strategy may be needed when dealing with cases
of severe obesity compared with cases of overweight.
• Information about the age of onset and the presence of parental obesity may help
clinicians identify people with a genetic predisposition to excessive weight gain.
Evidence-based statement Evidence level
Psychological stress can have variable effects on a person’s III-3
body weight.
Recommendation: level C
• Stress may need to be considered as a factor in obesity.
Evidence-based statement Evidence level
Several prescription medications can cause weight gain. II
Recommendation: level B

• A person’s current medication use should be assessed as a potential
cause of weight gain or failure to lose weight.
EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
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EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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Evidence-based statements Evidence level
Obesity in childhood and adolescence is a risk factor for III-2
obesity later in life.
The tracking of childhood obesity into adult obesity is stronger III-2
for older children than for younger ones.
Recommendation: level B
• When treating adults for overweight or obesity, the past history should
include height and weight in childhood.
Evidence-based statements Evidence level
Pregnancy and menopause are critical periods for weight gain III-2
in women.
It appears that a change in weight at menopause can be prevented II
by lifestyle change.
Hormone replacement therapy after menopause can result in II
reduced body-fat gain (particularly on the upper body)
when compared with a placebo.
Certain life events—for example, marriage, holidays, and giving IV
up sport—can have an influence on body fatness.
Quitting smoking can cause significant weight gain—on I
average 5 to 6 kilograms in the first year.
Recommendation: level B
• Instituting a weight-loss program at the time of quitting smoking may

help attenuate the weight gain that usually occurs after quitting.
Evidence-based statements Evidence level
Lack of motivation and a history of failed attempts to lose III-3
weight may make it more difficult to maintain a low body weight.
Psychological factors—including early life experiences—can IV
play an important part in the development of overweight or obesity.
Recommendation: level C
• Case histories for weight management should include an assessment of life
events, past history of weight-loss attempts, and psychological factors.
EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
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EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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M EA S U R EM E N T
There are no perfect clinical measures of overweight and obesity, and in some
cases there may be counter-productive effects of measurement on people who
are clearly overweight. For adults, a combination of waist circumference and BMI
is recommended for the clinical measurement of overweight and obesity. A BMI
above 25 or a waist circumference above 80 centimetres in women or 94 centimetres
in men is regarded as overweight. A BMI above 30 or a waist circumference above
88 centimetres in women or 102 centimetres in men is regarded as obesity. It
should be noted, however, that these cut-offs for overweight and obesity have
been derived in predominantly Caucasian populations and are likely to vary in
other population groups.
At present there are no data on the best measures to use for Aboriginal and
Torres Strait Islander peoples.
Evidence-based statement Evidence level
BMI is an acceptable approximation of total body fat at III-2

the population level and can be used to estimate the relative
risk of disease in most people. However, it is not always an
accurate predictor of body fat or fat distribution, particularly
in muscular individuals, because of differences in body-fat
proportions and distribution.
Recommendation: level B
• Interpret BMI with caution when this is the only measure of body fatness
in a person, particularly when measuring older people and muscular,
mesomorphic individuals such as athletes.
Evidence-based statement Evidence level
Waist circumference is a valid measure of abdominal fat III-2
mass and disease risk in individuals with a BMI less than 35.
If BMI is 35 or more, waist circumference adds little to the
absolute measure of risk provided by BMI.
Recommendations: level B
• To reduce the risk of disease, Caucasian men should aim for a waist circumference
of less than 102 centimetres and women less than 88 centimetres. In Asians and
Indians the target could be 10 centimetres lower, and in Pacic Islanders it could
be signicantly higher.
• If patients wish to be measured, a combination of BMI and waist circumference,
or weight and waist circumference, should be used.
EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
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EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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Recommendations: level D
• Both weight and waist circumference should be used to assess relative changes
in body fatness over time.

• For some obese patients measurement may be counter-productive; these
patients should be allowed to choose whether to have their fat mass measured.
Other patients may prefer not to know the results of measurement.
T RE AT ME N T: G E NE RA L
Obesity is a chronic problem. There is no single, effective treatment, and the problem
tends to recur after weight loss. People’s expectations of weight loss are often
unrealistic, but even a modest loss of 5 to 10 per cent of starting weight can result
in signicant health benets. At present, most research focuses on weight loss rather
than end-point diseases.
Statement
There is a range of treatment options for overweight and Expert opinion
obesity. The choice of treatment should be based on individual
considerations such as the severity of the problem and any
associated complications.
Evidence-based statement Evidence level
People’s expectations of weight-loss programs IV
are often unrealistic.
Recommendation: level D
• Efforts should be made to moderate people’s unrealistic expectations
of weight-loss programs.
Evidence-based statement Evidence level
Obesity is a chronic disorder that tends to recur IV
after weight loss.
Recommendation: level C
• People suffering from obesity should have long-term contact with, and
support from, health professionals.
EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS
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EVIDENCE-BASED STATEMENTS AND RECOMMENDATIONS

Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults
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Statement
As a complex disorder with multiple causes, obesity often Expert opinion
calls for multi-disciplinary attention.
Recommendations: level D
• If needed, clinicians should seek assistance from health professionals in other
disciplines with specialist knowledge in obesity management.
• The health benets and personal costs involved in weight loss vary considerably
between individuals, so consideration of treatment should take into account the
number of quality life-years to be gained, co-morbidities, the potential for successful
change, and the patient’s motivation.
Statement
There is no single effective treatment for long-term Expert opinion
weight loss. Lifestyle changes underlie all currently
effective treatments and should be emphasised.
T RE AT ME N T: E N ER GY I N TA K E
The effectiveness of any changes to eating behaviour depends on the
energy imbalance produced by a reduction in energy intake relative
to energy expenditure. There are many ways of achieving this, although
some of them are potentially dangerous.
Evidence-based statement Evidence level
The main requirement of a dietary approach to weight I
loss is a reduction in total energy intake.
Recommendation: level A
• A reduction in total energy intake remains the basic mechanism whereby all dietary
weight loss occurs. Evidence to date shows that low-fat ad libitum diets can result
in long-term weight loss. Other strategies have shown short-term effectiveness but
have not yet been assessed for long-term effect.
Evidence-based statements Evidence level

Low-fat ad libitum diets that reduce daily energy intake by I
2 to 4 megajoules can lead to a weight loss of 2 to 6 kilograms
and a waist-circumference loss of 2 to 5 centimetres after
one year of treatment.
There is some evidence that these diets, if intensively monitored, may II
be more effective in maintaining weight loss than more restrictive
prescriptive, low energy diets.
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Recommendation: level B
• Patients can benefit from being taught how to recognise and reduce fat in their diet
in such a way as to maintain the micronutrient integrity of the diet.
Evidence-based statement Evidence level
Nutritionally balanced low-energy diets of 4 to 5 megajoules a I
day can result in weight losses of 7 to 13 kilograms and significant
decreases in abdominal fat after six months’ treatment. But this
weight loss is not sustained: half of the weight lost is regained after
one to two years of treatment.
Recommendation: level B
• Low-energy diets should not be considered for continuous long-term treatment
of overweight and obesity. When they are used, close supervision is essential.
Evidence-based statement Evidence level
Very low energy diets produce greater initial weight loss I
than other forms of energy restriction (9 to 26 kilograms
over four to 20 weeks). Long-term maintenance of this weight
loss over one to two years is variable (–14 to 0 kilograms),

and success is more likely if behavioural or drug therapy is
used as a follow-up.
Recommendation: level B
• Very low energy diets can result in quick, short-term weight losses, but they
should be closely monitored and should not be used for extended periods.
Behavioural or drug therapy as a follow-up increases the likelihood of maintaining
some of the weight loss.
Evidence-based statement Evidence level
Use of meal replacements for one to five years can II
produce weight losses of 3.0 to 9.5 kilograms and significant
improvements in several co-morbid factors in overweight
and obese people.
Recommendation: level B
• Clinically significant weight loss can be achieved using meal-replacement programs.
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Statement Evidence level
There is curently no long-term evidence supporting the use Long-term
of 'popular'diets (for example, low-carbohydrate diets and evidence
single-food diets). Some diets—such as those involving modified not available
fats, increased protein and a low glycaemic index—show
promise in short-term studies. No long-term data are available.
Although epidemiological studies show little relationship between III-I
alcohol intake and BMI in men, and even an inverse relationship
in women, experimental studies suggest that alcohol energy
is additive to the normal diet, and that it contributes

to excess energy intake and fat storage.
T RE AT ME N T: E N ER GY E X PE ND I T U RE
In the short term it is more difcult to cause an energy imbalance that leads
to weight loss through physical activity than it is through dietary restriction.
A regular pattern of daily activity is, however, one of the keys to long-term
maintenance of weight loss.
Evidence-based statements Evidence level
In modern societies there is an association between III-3
low levels of physical activity and obesity.
In the absence of dietary change, moderate to vigorous I
exercise at the level usually prescribed—three to five hours
a week—produces a modest weight loss (about 2 kilograms)
over one year.
Physical activity appears to be associated with a reduction III-2
in abdominal fat.
Physical activity as part of a weight-loss program can help II
decrease total body fat while generally preserving fat-free mass.
Weight loss can be expected to occur in a dose-response III-2
fashion, increasing with an increasing volume of physical activity.
Recommendation: level B
• Recommendations for physical activity for weight loss should be based on activity
volume, where volume is dened by frequency, duration and intensity.
Recommendations: level D
• When overweight or obesity is associated with low cardiovascular tness, the volume
of physical activity should be based on frequency and duration but not intensity.
• When a person’s cardiovascular fitness is high but overweight or obesity
persists, more intense levels of activity may be considered.
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Evidence-based statement Evidence level
Lifestyle-based increases in physical activity—as opposed II
to a structured exercise program—are likely to be more
successful for weight loss in the long term.
Recommendation: level B
• Patients should be advised to comply with the National Physical Activity Guidelines
and the National Dietary Guidelines as a minimum requirement for body-weight
maintenance.
Recommendations: level C
• Lifestyle-based changes that increase the physical activity volume signicantly above
the baseline level are likely to be the most successful for long-term weight loss.
• Patients should be encouraged to increase their physical activity level in order to gain
associated health benefits, even in the absence of significant losses in body weight.
Evidence-based statement Evidence level
There is no single ‘best’ exercise for weight loss. Resistance III-1
training may provide benefits in terms of retention of lean body
mass, but it offers no apparent extra advantages, for either
weight loss or fat loss, over accumulated aerobic activity.
Recommendations: level D
• Depending on initial tness, health status, personal preferences, and lifestyle, any
of several types of physical activity may be the right one for a particular individual.
• It is important to prescribe physical activity that a patient prefers and is therefore
likely to maintain in the long term.
• For very immobile obese patients, a reduced weight-bearing form of activity
(such as swimming, walking in water, or cycling) may be best in the early stages
of a weight-loss program, until their fitness increases and weight-bearing activities
(such as walking) can be more easily carried out.

Evidence-based statements Evidence level
There can be significant individual differences in the weight-loss II
response to a set amount of physical activity.
Even in the absence of weight loss, increases in physical activity III-2
can improve metabolic health and may protect against certain
diseases (diabetes and cardiovascular disease, for example)
and early mortality.
Long-term (more than two years) studies have demonstrated II
that physical activity can limit fat mass and weight regain more
effectively than diet.
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There is an inverse relationship between the volume of physical III-1
activity carried out and weight regain.
Weight regain after one year is likely to be up to 40 per cent with II
30 minutes of moderate activity daily but less than 15 per cent with
80 minutes or more of daily activity. Therefore, an activity level equivalent
to about 45 kilojoules per kilogram per day (about 80 minutes a day)
is probably the minimum required for effective weight maintenance.
Physical activity is likely to be more effective when combined with II
energy restriction, leading to a further 3 to 6 kilograms of weight
loss and greater loss of abdominal fat than ad lib low-fat diets or
physical activity alone over one year.
A mean weight loss of 7.5 kilograms observed one year after II
diet-plus-physical activity therapy falls to 3.1 kilograms with longer
treatment, although this remains a significantly better outcome than

that associated with no treatment at all.
Recommendation: level B
• Physical activity should be a component of any weight-loss program, particularly for
improving the effectiveness of weight maintenance.
T RE AT ME N T: B E HAV I O UR A L TH E R A PY
Behavioural therapy can increase the effectiveness of other weight-loss treatments;
the duration of the therapy is related to the extent of weight-loss maintenance.
Evidence level
Overall, behavioural therapy used in combination with II
other weight-loss approaches can induce a mean weight
loss of about 5 kilograms, although this is variable
(0 to 13 kilograms). Three to five years after intervention
ceases, weight loss falls to about 3 kilograms (0 to 10 kilograms).
Recommendation: level B
• For optimal results, aspects of behavioural therapy should be combined
with nutrition and physical activity.
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Evidence-based statements Evidence level
Long-term (more than a year) behavioural therapy used in II
combination with other weight-loss interventions can be
associated with reductions in abdominal fat, even in the absence
of weight loss.
Behavioural therapy can
• improve compliance with dietary and physical activity requirements II
• reduce blood pressure II

• improve psychological function. III-3
No single behavioural therapy strategy appears to be superior II
to any other in the population as a whole.
Increased duration of behavioural treatment increases the II
likelihood of maintaining weight loss; in the absence of continued
behavioural intervention, a return to baseline weight occurs in the
great majority of subjects.
Behavioural therapy adds to the benefits associated with all other II
forms of weight-loss treatment.
Recommendation: level B
• Consideration should be given to making aspects of behavioural therapy—
for example, self-monitoring, social support and stimulus control—a part
of all weight-loss interventions.
T RE AT ME N T: P H AR MAC OT H E RA P Y
Research into new anti-obesity drugs is moving quickly, and recommendations may
need to be updated. The four medications currently available in Australia—orlistat,
sibutramine, phentermine, and diethylpropion—appear to be effective for continued
weight loss, although phentermine and diethylpropion are indicated only for short-
term use. Because there is no long-term (over two years) information published in
the peer-reviewed literature on the potential harmful effects of these medications,
it is incumbent on the practitioner to prescribe with caution.
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Evidence-based statements Evidence level
The dopaminergic agents phentermine and diethylpropion can II
produce effective weight losses of 6 to 7 kilograms (3 to 3.6

kilogram more than placebo), but are currently indicated only
for short-term use.
Some SSRI (selective serotonin re-uptake inhibitor) II
antidepressant medications can result in weight loss in some
people under well-controlled conditions, although the effect
may be transient despite continued use of drugs.
Sibutramine can lead to a weight loss of 5.6 kilograms or about I
6 per cent (4.3 kilogram more placebo), and improve some co-morbid
factors after one to two years of treatment. If it is preceded by, or
combined with, lifestyle and dietary modifications, weight loss in some
individuals can almost double, to 10.8 kilograms, ranging from 5 to
17 kilograms (4 to 5 kilogram above placebo), or about 10.7 per cent.
The safety of prolonged (more than two years) therapeutic
use of sibutramine has, however, not been demonstrated.
The medication should be used with caution in patients
with a history of hypertension, and its use is not recommended
in patients with coronary artery disease, arrhythmias,
congestive heart failure, or stroke.
Orlistat combined with a low-energy, low-fat diet can I
lead to a weight loss of 8.4 kilograms ranging from 6 to
13kilograms (1.1 to 4.5 kilogram above placebo), or about
8.6 per cent, and improve some co-morbid factors after one
to two years of treatment. Two-thirds of this weight loss is
the result of diet modification.
A recently completed study published in abstract format Level of evidence
has shown efficacy and safety in patients over a four-year yet to be assigned
treatment period.
Both sibutramine and orlistat can increase the likelihood I
of long-term maintenance of weight loss while the drug
is being taken.

Recommendation: level A
• Pharmacotherapy can be a useful adjunct to lifestyle change to induce weight loss in
some patients with a BMI greater than 30 and in patients with a BMI greater than 27
with co-morbidities. It is, however, clear that—like therapy for other chronic disorders
such as hypertension, diabetes and dyslipidaemia—the medication is effective only
while it is being taken. In the absence of long-term (more than two years) peer-
reviewed data, the long-term risk-benefit ratio of new drugs cannot be predicted.
Drugs should be used only under careful medical supervision and in the context
of a long-term treatment strategy.
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T RE AT ME N T: S U RG ERY
Surgery is the most effective treatment for severe obesity: for most procedures
good weight maintenance has been observed three to eight years after surgery
in most patients.
Evidence-based statement Evidence level
Surgical procedures in motivated, morbidly obese patients III-2
can result in weight losses of from 16 to 43 per cent
(varying between 22 and 63 kilograms) that are reasonably
well maintained over three to eight years.
Recommendation: level B
• Surgery is the most effective treatment for morbid obesity: for most procedures
and most patients, good weight maintenance has been observed three to eight
years after surgery.
Evidence-based statements Evidence level
Surgically induced weight loss results in a marked reduction III-2

in the incidence and severity of some of the co-morbidities
associated with obesity (particularly diabetes) and improved
quality of life.
Obesity surgery may prove cost-effective in morbidly obese IV
patients after two years.
In patients with acceptable operative risks, mortality as a III-2
consequence of bariatric surgery is low. Bariatric surgery is,
however, often associated with impaired absorption of micronutrients,
which requires lifelong monitoring and often folate or vitamin B
supplementation.
Recommendation: level B
• Assessing both peri-operative risk and possible long-term complications
is important; the risk-benefit ratio should be assessed in each case.