The BMI System For Diabetes Is Failing People Of Colour

“A blanket approach is not acceptable any longer."

Researchers are calling for changes to the BMI system to ensure people from Black, Asian and minority ethnic backgrounds, who are at risk of type 2 diabetes, do not “slip through the net”.

The study, involving 1.5 million people in England, found people of colour are more likely to develop type 2 diabetes at a much lower BMI than people from white ethnic backgrounds. However, outdated “cut-offs” might mean these cases are missed.

The researchers used their findings to create new ethnic-specific obesity cut-off points and are urging the NHS to adopt these as standard practices to avoid people from these backgrounds not being checked for type 2 diabetes as early as their white counterparts.

The study’s principal investigator Dr Rishi Caleyachetty, a junior doctor and epidemiologist at the University of Warwick, sad: “As a doctor, I’m extremely concerned that if the current BMI values are not amended to account for ethnicity, many people will needlessly slip through the net, leaving them unknowingly at risk of type 2 diabetes.

“I meet people from [these] backgrounds who tell me about the lack of information on what a healthy weight is for their community, another person, who had been told they were at high risk of developing type 2 diabetes told me he was surprised because he was not ‘fat’.

“These are just two examples from many cases, indicating that a ‘blanket’ set of BMI values could be disadvantaging people from accessing services to prevent type 2 diabetes.”

He added: “We hope that this study will swiftly kickstart a review of current BMI policy in the UK for people from Black, Asian and minority ethnic backgrounds, in order to prevent both type 2 diabetes, and facilitate early and effective treatment of type 2 diabetes.”

A person’s BMI is calculated by analysing their height and weight. According to current NHS guidelines an adult with a BMI of 30Kgm-2 or above is obese, and action will be taken at this stage to prevent type 2 diabetes.

The study found: “For the equivalent age and sex-adjusted incidence rate of type 2 diabetes at a BMI of 30Kgm-2 in white populations, the BMI cut-offs for people of colour were much lower: for South Asians, 23.9; Chinese, 26.9; black, 28.1; and Arab 26.6.”

The study, funded by the National Institute for Health Research (NIHR) and undertaken by four leading UK Universities in partnership with the Ethnic Forum, analysed data from GP and hospital records of individuals aged 18 and over who were registered with a UK GP between 1990-2018.

A co-investigator on the study, Dr Paramjit Gill, professor of general practice and head of the division of health sciences at the University of Warwick, said: “This work highlights that we need evidence for all ethnic groups as they are at risk of diabetes at different levels of BMI.

“A blanket approach is not acceptable any longer.”