Researchers are calling for changes to the BMI system to ensure BAME people who are at risk of type 2 diabetes do not “slip through the net”.

The study, involving 1.5 million people in England, found that outdated BMI cut-offs mean people from BAME backgrounds are more likely to develop type 2 diabetes at a much lower BMI than people from white ethnic backgrounds.

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 BAME backgrounds not being checked for type 2 diabetes as early as their white counterparts.

This work highlights that we need evidence for all ethnic groups as they are at risk of diabetes at different levels of BMI

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 BAME people will needlessly slip through the net, leaving them unknowingly at risk of type 2 diabetes.

“I meet people from BAME 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 BAME 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 BAME people, in order to prevent both type 2 diabetes, and facilitate early and effective treatment of type 2 diabetes.

“We all know the NHS was founded on the principles of fairness and that all patients regardless of their background should be cared for equally, but it is clear at the moment these principles may not be a reality for many BAME people.”

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 that: “For the equivalent age and sex-adjusted incidence rate of type 2 diabetes at a BMI of 30Kgm-2 in white populations, the BAME BMI cut-offs 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.”