1 Recommendations

The evidence statements underpinning the recommended approaches are listed in The evidence.

See also Supporting evidence for the evidence reviews and expert reports.

For the research recommendations and gaps in research, see Recommendations for research and Gaps in the evidence respectively.

Background

WHO recommendations

In 2004, the World Health Organization (WHO) assessed whether the international body-mass index (BMI) cut-off points for determining if someone is overweight (BMI 25 kg/m2) or obese (BMI 30 kg/m2) were appropriate for Asian populations.

WHO concluded that these thresholds were probably not appropriate, as there is a high risk of type 2 diabetes and cardiovascular disease among Asian groups at a BMI lower than 25 kg/m2.

Due to lack of data in 2004, it was not possible to redefine thresholds for all Asian groups and WHO recommended that the current thresholds (BMI 25 kg/m2 and 30 kg/m2) should be retained as international classifications. At the same time, it suggested a number of public health action points should be used in relation to BMI and Asian populations (see box 1). WHO did not attempt to assess this issue for black or other minority ethnic groups.

Definitions

The Public Health Interventions Advisory Committee (PHIAC) considered black and other minority ethnic groups, as well as Asian groups, when developing this guidance.

For the purpose of this guidance black, Asian and other minority ethnic groups are defined as follows:

  • South Asian people are immigrants and descendants from Bangladesh, Bhutan, India, Indian-Caribbean (immigrants of South Asian family origin), Maldives, Nepal, Pakistan and Sri Lanka[1].

  • African-Caribbean/black Caribbean people are immigrants and descendants from the Caribbean islands (people of black Caribbean family origin may also be described as African-American).

  • Black African people are immigrants and descendants from African nations. In some cases, they may also be described as sub-Saharan African or African-American.

  • 'Other minority ethnic groups' includes people of Chinese, Middle-Eastern and mixed family origin, as follows:

    • Chinese people are immigrants and descendants from China, Taiwan, Singapore and Hong Kong.

    • Middle-Eastern people are immigrants and descendants from Egypt, Iran, Iraq, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, the United Arab Emirates and Yemen.

    • people of mixed family origin have parents of 2 or more different ethnic groups.

Conclusions

The evidence gathered does confirm that people from these groups are at an equivalent risk of diabetes, other health conditions or mortality at a lower BMI than the white European population.

However, the Committee did not consider the evidence sufficient to make recommendations on the use of new BMI and waist circumference thresholds to classify whether members of these groups are overweight or obese. There was also insufficient evidence to make recommendations on the full range of health conditions considered, or all-cause mortality (most of the evidence came from diabetes studies).

Thus, this guidance supports previously published NICE recommendations on diabetes prevention. It also highlights recommendations from NICE and other sources in relation to awareness raising, BMI measurement and thresholds that can be used as a trigger for intervening.

Who should take action?

A wide range of individuals and groups should implement the recommendations. This includes: commissioners, managers and practitioners working in the NHS, local authorities and the wider public, private, voluntary and community sectors. For a detailed list see Who is this guidance for?

Recommendation 1 Preventing type 2 diabetes

Follow NICE recommendations 1–18 in Preventing type 2 diabetes: risk identification and interventions for individuals at high risk (public health guidance 38). This includes:

  • using lower thresholds (23 kg/m2 to indicate increased risk and 27.5 kg/m2 to indicate high risk) for BMI to trigger action to prevent type 2 diabetes among Asian (South Asian and Chinese) populations

  • identifying people at risk of developing type 2 diabetes using a staged (or stepped) approach

  • providing those at high risk with a quality-assured, evidence-based, intensive lifestyle-change programme to prevent or delay the onset of type 2 diabetes.

  • Extend the use of lower BMI thresholds to trigger action to prevent type 2 diabetes among black African and African-Caribbean populations.

  • Raise awareness of the need for lifestyle interventions at a lower BMI threshold for these groups to prevent type 2 diabetes. For example, see box 1. In particular, use the public health action points advocated by WHO as a reminder of the threshold at which lifestyle advice is likely to be beneficial for black and Asian groups to prevent type 2 diabetes.

Recommendation 2 BMI assessment, multi-component interventions and best practice standards

Follow NICE recommendations on BMI assessment, and how to intervene, as set out in Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children (NICE clinical guideline 43). Specifically:

  • Clinicians should assess comorbidities, diet, physical activity and motivation along with referral to specialist care if required. See Recommendation 1.2.3 Assessment

  • Weight management programmes should include behaviour-change strategies to increase people's physical activity levels or decrease inactivity, improve eating behaviour and the quality of the person's diet and reduce energy intake. See Recommendation 1.2.4 Lifestyle interventions

  • Primary care organisations and local authorities should recommend to patients, or consider endorsing, self-help, commercial and community weight management programmes only if they follow best practice. See Recommendation 1.1.7 Self-help, commercial and community programmes

Recommendation 3 General awareness raising

  • Ensure practitioners are aware that members of black, Asian and other minority ethnic groups are at an increased risk of chronic health conditions at a lower BMI than the white population (below BMI 25 kg/m2).

  • Ensure members of black, Asian and other minority ethnic groups are aware that they face an increased risk of chronic health conditions at a lower BMI than the white population (below BMI 25 kg/m2).

  • Use existing local black and other minority ethnic information networks to disseminate information on the increased risks these groups face at a lower BMI.

Box 1: International guidance on BMI/waist circumference thresholds

WHO advice on BMI public health action points for Asian populations (World Health Organization 2004)

White European populations

Asian populations

Description

Less than 18.5 kg/m²

Less than 18.5 kg/m²

underweight

18.5–24.9 kg/m²

18.5–23 kg/m²

increasing but acceptable risk

25–29.9 kg/m²

23–27.5 kg/m

increased risk

30 kg/m² or higher

27.5 kg/m² or higher

high risk

International Diabetes Federation guidance on waist circumference thresholds as a measure of central obesity (Alberti et al. 2007)

European

Men

≥ 94 cm (37 inches)

Women

≥ 80 cm (31.5 inches)

South Asians

Men

≥ 90 cm (35 inches)

Women

≥ 80 cm (31.5 inches)

Chinese

Men

≥ 90 cm (35 inches)

Women

≥ 80 cm (31.5 inches)

Japanese

Men

≥ 90 cm (35 inches)

Women

≥ 80 cm (31.5 inches)

Ethnic south and central Americans

Use south Asian recommendations until more specific data are available

Sub-Saharan Africans

Use European data until more specific data are available

South Asian Health Foundation position statement on BMI and waist circumference (Kumar et al. 2010)

Recommends lower thresholds for advising South Asians to adopt a healthier lifestyle and avoid further weight gain. States that South Asians should be targeted as a special group for raising awareness of the risks of obesity. The Foundation supports a lower threshold of 23 kg/m2 for classification as overweight in British South Asians, as suggested by other expert groups. It acknowledges that more research is needed to establish appropriate thresholds for waist circumference in different sub-groups. In the meantime, it suggests that men with a waist circumference greater than 90 cm (35 inches) and women with a waist greater than 80 cm (31.5 inches) should be considered overweight.

Other guidance is available from:

  • Scottish Intercollegiate Guidelines Network (2010)

  • Ministry of Health India (Misra et al. 2009)

  • Ministry of Health Singapore (Health Promotion Board Singapore 2005)

  • Obesity in Asia Collaboration (2007)

  • Cooperative meta-analysis group of the working group on obesity in China (Zhou 2002)



[1] South Asian Public Health Association (2011) FAQ: Who is considered South Asian? [online]

  • National Institute for Health and Care Excellence (NICE)