Smoking, nutrition, alcohol, physical activity (SNAP)

Overweight and obesity
☰ Table of contents

3.2.1 Ask and assess

Body mass index (BMI) and waist circumference should be measured and noted in a patient’s medical record every two years.59 BMI on its own may be misleading, especially in older people and muscular individuals, and classifications may need to be adjusted for some ethnic groups.

Waist circumference is a strong predictor of health problems such as CVD, diabetes and metabolic syndrome.60,61 BMI may not correspond to the same degree of risk in different populations due, in part, to different body proportions. In Asian populations, for example, BMI greater than 23 may convey increased risk.62

Explanation of the patient’s risk should avoid terms such as ‘obese’, which may offend patients. Diet and physical activity should be assessed in all patients who are overweight or obese (refer to Section 3.3).

Waist circumference

An adult’s waist circumference is measured halfway between the inferior margin of the last rib and the crest of the ilium in the mid-axillary plane. The measurement is taken at the end of normal expiration.

Table 6. Nutrition: waist circumference (adults)




Increased risk

>94 cm

>80 cm

High risk

>102 cm

>88 cm

For children, a waist-to-height ratio of ≥ 0.5 may be used to guide consideration of the need for further assessment of cardiovascular risk in children.59


BMI is equal to body weight in kilograms divided by the square of height in metres. As previously mentioned, BMI on its own may be misleading, especially in older people and muscular individuals, and classifications may need to be adjusted for some ethnic groups.

Table 7. Nutrition: healthy weight: BMI (kg/m2)



Risk of morbidities




Normal weight




25 or greater


Obese I



Obese II



Obese III

40 or greater

Very severe

People who are overweight have a higher risk of disease, including coronary heart disease, diabetes, dyslipidaemia, hypertension, and bone and joint disorders.

The presence of excess fat in the abdomen is an independent predictor of morbidity.

The patient’s health literacy and motivation to lose weight should be assessed in order to better target advice.

Blood pressure should be measured in all patients aged 18 and older, and lipids measured in patients aged 45 and older.

Interpretation of BMI values in children and adolescents aged 2–18 is based on sex-specific BMI percentile charts.

For further information on the management of obesity, refer to the NHMRC Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults, Adolescents and Children in Australia


3.2.2 Advise, agree and assist

Patients who are overweight or obese should be offered individual education and skills training. Advice should be tailored to the degree of overweight.

Table 8. Nutrition: what advice should be provided (and to whom)?



Level of evidence and strength of recommendation59

What dietary advice should be provided?

The current Australian Dietary Guidelines and resources to assist health professionals and educators should be used as the basis of advice on nutrition for adults. For adults who are overweight or obese, design dietary interventions for weight loss to produce a 2500 kilojoule per-day energy deficit and tailor programs to the dietary preferences of the individual. This should involve reduced saturated-fat and high-sugar drinks and food. The size of food portions should be reduced. Advice needs to be tailored to the patient’s health literacy and checks made to ensure patients have understood.


What physical activity should be recommended?

Approximately 300 minutes of moderate-intensity activity, 150 minutes of vigorous activity, or an equivalent combination of both, each week, combined with reduced dietary intake. Any increase consistent with the patient’s medical condition should be encouraged. This should start with moderate physical activity.


What is recommended for adolescents and children?

Focus lifestyle programs on parents, carers and families. Advise that weight maintenance is an acceptable approach in most situations for children who are overweight or obese. Recommend lifestyle changes, including reducing energy intake and sedentary behaviour, and increasing physical activity based on current Australian dietary and physical activity guidelines. Restrictive dieting is not recommended for children and adolescents.


What should the goals for weight loss in adults be?

To achieve a sustainable weight reduction (eg. 1–4 kg per month in the short term, 5–10% of initial body weight in the long term).


There is a range of treatment options for adults. Individual education and simple behavioural interventions are appropriate for some overweight patients, while behavioural approaches may be more appropriate for those with disordered eating patterns. Behaviour-change techniques include goal setting, self-monitoring of behaviour and progress, stimulus control (eg. recognising and avoiding triggers that prompt unplanned eating), cognitive restructuring (modifying unhelpful thoughts or thinking patterns) or problem-solving.59

Intensive interventions

Intensive interventions to support weight loss may be considered when an adult has a BMI of >30 kg/m2 or >27 kg/m2 with risk factors and/or comorbidities, or has been unsuccessful in reducing weight or preventing weight regain using lifestyle approaches. Intensive interactions may include:

  • very low-energy diets for 8–16 weeks under medical supervision, replacing one or more meals each day with foods or formulas that provide a specified number of kilojoules (eg. 1675–3350 kJ)
  • drug therapy – Orlistat may be considered as an adjunct to lifestyle interventions, taking into account the individual situation. Phentermine is registered for short-term use (eg. three months), but is associated with a range of side effects, such as hypertension, tachycardia and insomnia, and a risk of tolerance. The long-term safety of phentermine has also not been tested.


3.2.3 Arrange

People with obesity should have long-term contact with, and support from, healthcare professionals. Multidisciplinary care from appropriate services or an allied health professional, such as a dietitian and exercise physiologist, is recommended, especially in complex cases and for patients with morbid obesity.

Consult the ‘Find a Dietitian’ section of the Dietitians’ Association of Australia website or call 1800 812 942 to find a dietitian in your local area. Contact details of local dietetic services should be included in the practice directory (refer to Section 4.5.4).

Patients living with obesity who have a chronic medical condition and complex needs may benefit from a GP Management Plan and Team Care Arrangement, especially if other conditions are present. Aboriginal and Torres Strait Islander patients are eligible for annual health assessments, which may be followed by up to 10 occasions of service by a practice nurse or Aboriginal Health Worker (AHW) and five occasions of service from allied health providers (within one year). Refer to Chapter 5 for more information on health assessments and management plans, as well as for further referral services. Local private and public community programs may be appropriate.

Bariatric surgery may be considered in adults with a BMI of >40 kg/m2 or >35 kg/m2 with comorbidities that may improve with weight loss.59 Bariatric surgery should be part of an overall clinical pathway for adult weight management that is delivered by a multidisciplinary team (including surgeons, dietitians, nurses, psychologists and physicians) and includes planning for continuing follow-up. Although obesity rates are higher in rural areas, specialist services may not be available and access may require travel, increasing the cost to patients.

Referral to hospital or paediatric services may be considered for children and adolescents if:

  • they are aged 2–18 and have a BMI well above the 95th percentile on United States Centers for Disease Control and Prevention (CDC) growth charts or the 97th percentile on World Health Organization (WHO) growth charts
  • they are younger than two years, above the 97th percentile on WHO growth charts and gaining weight rapidly
  • they may have serious related comorbidities that require weight management (eg. sleep apnoea, orthopaedic problems, risk factors for CVD or type 2 diabetes, psychological distress)
  • an underlying medical or endocrine cause is suspected, or there are concerns about height and development.


The plan for weight loss should be reviewed after two weeks in order to determine its suitability for that individual and whether modification is required. The practice information system should generate reminders or lists of patients overdue for follow-up (refer to Section 4.5.1). Relapse and weight gain are common. Patients should be followed up at yearly intervals over five years after weight reduction is achieved.

  1. National Health and Medical Research Council. Clinical practice guidelines for the management of overweight and obesity in adults, adolescents and children in Australia. Canberra: NHMRC; 2013.
  2. Welborn TA, Dhaliwal SS, Bennett SA. Waist-hip ratio is the dominant risk factor predicting cardiovascular death in Australia. Med J Aust 2003;179(11–12):580–5.
  3. Wang Y, Rimm EB, Stampfer MJ, Willett WC, Hu FB. Comparison of abdominal adiposity and overall obesity in predicting risk of type 2 diabetes among men. Am J Clin Nutr 2005;81(3):555–63.
  4. World Health Organization Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet 2004;363(9403):157–63.