Last updated on 5 May​ 2023

Body Mass Index (BMI) is useful as an initial screening tool to identify people who may have health problems associated with being under or overweight.

The BMI Control Care Protocol is designed for individuals aged 18 to 65 years old.

Do not use for people aged <18 years, pregnant women and very muscular people (e.g. athletes). For those aged > 65 years, use BMI with prudence.

Measurement and Definition of BMI1

  1. Measure BMI Routinely. Definition of BMI = Weight (kg)/(Height (m) X Height (m))

    • ​BMI cut-off points in Asians​ 

  2. Consider measuring waist circumference.

Clinical Assessment1​​

Through a focused history, physical examination, and investigations​​:

  1. Identify possible causes of obesity

  2. Assess risk factors

    • ​Presence of metabolic syndrome​

    • 10-year Coronary Artert Disease (CAD)  risk score

  3. Complications associated with obesity

Waist Circumference​ 

As part of a complete cardiovascular risk assessment, waist circumference measurement is recommended for all individuals. A high waist circumference ≥ 90cm for males and ≥80cm for females increases the likelihood of cardio metabolic risk factors such as type 2 diabetes, lipid disorder or hypertension. Waist circumference will likely be elevated for BMI ≥32.5.​​

Definition of Metabolic Syndrome2

The presence of any three out of the following five traits:

Table 1: Traits of Metabolic Syndrome

​Abdominal​ obesity
≥ 90 cm in men and ≥ 80 cm in females (Asian cut-offs)
​≥ 1.7 mmol/L (150mg/dL)
3​ ​HDL cholesterol​
​≤ 1.0 mmol/L (38mg/dL) in men or ​ 1.3 mmol/L (50mg/dL) in women
4​ ​Blood pressure​
​≥ 130/85 mmHg or treatment for high blood pressure​​
​Fasting plasma glucose
≥ 6.1 mmol/L (110mg/dL) or on treatment for diabetes

Presence of metabolic syndrome puts a person at higher risk of developing Type 2 Diabetes Mellitus (DM) and cardiovascular disease.​

Treatment Goals​1​​

For Asians with BMI of ≥23 kg/m2 and/or high waist circumference, introduce the following where applicable:​

  1. ​Reduce body weight by 5 to 10% over 6 to 12 months.
  2. Therapy: diet, exercise​, behavioural, drug, surgery​​​

Figure 1
 below provides a framework to guide clinicians on the management approach and types of programmes that can be recommended to patients aged 18 to 65, depending on their profile.

For patients above 65 years old, clinicians may examine the history of weight change over patients' lifetimes to gain a more complete understanding of their risk profiles (e.g. recent, unintentional weight loss may require further investigation). For patients with high BMI, identify if they have conditions and/or risk factors that would make weight loss desirable (e.g., diabetes, osteoarthritis). For patients with low BMI or who are pre-frail/frail, muscle strengthening activities and multi-component physical activity that emphasises strength and functional balance should be recommended4​ to reduce sarcopenia as well as risk of falls and fractures.

Figure 1: BMI control management framework for 18 to 65 year olds.

BMI Control Management Framework.png Physical Activity Recommendation Process (PARP) Workflow ​​

Full list of subsidised weight management programmes offered under Healthier SG: Green Segment​, Orange Segment, Red Segment​.


“Green" segment

As patients in this group do not have significant risk factors, you may encourage them to sign up for programmes via HPB's Healthy 365 (H365) application​ , including those from HPB, SportSG and People's Association (PA). Click here​ for a list of available "green" segment programmesSelf-administered assessment may be performed with the recommended tools such as the Physical Activity Readiness Questionnaire (PAR-Q) or Get Active Questionnaire (GAQ). 

Indicators of physical activity (step count, moderate to vigorous physical activity [MVPA] minutes), patient's diet logging, and participation in national programmes administered by HPB, will be captured on the patient's H365 app.

“Orange" segment

As patients in this group have risk factors that may predispose them to cardiovascular events during physical activity, exercise pre-participation assessment by their enrolled doctor is recommended. Refer to the Physical Activity Recommendation Process (PARP)  workflow. 

Given the need for patient education on exercise, diet and other lifestyle changes for chronic disease management, physicians may consider referring their patients to structured weight management programmes​. Patients with well-controlled chronic diseases can be referred Active Health Targeted Programmes managed by SportSG and run by accredited Exercise is Medicine trained coaches.  Click here​ for a list of "orange" segment programmes. It is recommended to complete a referral form for these programmes so that the Health Coach can tailor and proceed with the exercise recommendation directly with the patient.  More details on SportSG’s referral workflow are available here .

For patients with poorly-controlled chronic diseases, the focus of treatment should be the proper management of their chronic diseases. GPs should work with other members of their care teams to achieve this. GPs may wish the contact their PCN HQs for support from care teams who can counsel patients on diet, exercise and other lifestyle modifications which can contribute to both improved chronic disease and weight management. Patients with poorly controlled chronic diseases should also be monitored more closely by the care team to ensure the safety and adherence to the management regime. Where clinically relevant and beyond the capabilities of the PCN, GPs and/or their PCN teams may seek support for their patients from other available sources (e.g. community / primary care resources, cluster support) for the management of poorly controlled chronic conditions or weight-related issues. 

“Red" segment 

As patients in this group have significant risk factors that will predispose them to cardiovascular events during physical activity, exercise pre-participation assessment by a doctor is recommended. Refer to the Physical Activity Recommendation Process (PARP)  workflow. 

Given the need for patients to be educated and supported on the interactions between exercise and change in diet on underlying chronic diseases, you may consider referring to specialists or to tertiary-based obesity/ weight management programmes.  In general, listed weight management programmes for the “red” segment will accept patients who meet the following criteria:

  1. Age:
    •  18 to 65

  2. BMI / health status:
    •  BMI 32.5 to <37.5 (for patients with comorbidities) and
    •  BMI ≥ 37.5 (for patients with or without comorbidities)

Details on the “red" segment programmes can be found here. Some programmes   may also accept patients outside of the stated criteria (e.g., those below BMI of 32.5, or over the age of 65).

Once patients transit out of tertiary-based weight management programmes, GPs should consider referring them to community based structured weight management programmes and/or lifestyle counselling. De-escalation of programmes should be performed in tandem with the progress of patients with regard to weight change and chronic conditions patients may have.​


Medications should not be prescribed for cosmetic reasons and should be used as an adjunct to lifestyle modification.  Consider referring to a Specialist for shared care if medications are indicated.  Medications licensed for obesity in Singapore include Phentermine, Orlistat, Liraglutide and Contrave.

​Indications for prescribing medications for obesity:

BMI ≥30 kg/m2 with or without obesity-related complications or risk factors OR When BMI is 27.5 – 29.9 kg/m2 among Asians with co-morbidities or complications of obesity such as hypertension, Type 2 Diabetes Mellitus.​


Indications: Clinically severe obesity

For Asians, BMI ≥37.5 kg/m2 OR BMI ≥32.5 kg/m2 with conditions like Type 2 Diabetes Mellitus, hypertension, lipid disorder, fatty liver, polycystic ovarian syndrome, obstructive sleep apnoea and metabolic syndrome.

Consider referring to specialists or to tertiary-based obesity/ weight management programmes should surgery be considered. Depending on the procedure, the mean weight loss after 10 years ranged from 14 to 25%.​​

The following data fields should also be documented in GPs' case notes as part of good clinical practice for all patients enrolled to their practice.

Submission of data fields marked with asterisks* is required for subsidy claims and Healthier SG payments.​

  1. Weight*

  2. Height*

  3. BMI (in kg/m2; auto-calculated based on data input)

  4. Waist Circumference (in cm)

  5. Date*

  1. HPB & MOH. HPB-MOH Clinical Practice Guidelines 1/2016: Obesity [Internet]. 2016 [cited 2022 August 17]. 

  2. Health Promotion Board. Metabolic Syndrome. 2022 [cited 2022 Dec 20]. ​

  3. Harris TB. Weight and Body Mass Index in Old Age: Do They Still Matter? J Am Geriatr Soc. 2017 Sep;65(9):1898-1899. doi: 10.1111/jgs.14952. Epub 2017 Jul 17. PMID: 28714125; PMCID: PMC5704942. [cited 2022 November 23]

  4. SportSG & MOH. Singapore Physical Activity Guidelines (SPAG) [Internet]. 2022 [cited 2022 November 23]​​​​