{"id":508,"date":"2026-06-17T11:00:45","date_gmt":"2026-06-17T10:00:45","guid":{"rendered":"https:\/\/research.shu.ac.uk\/shusize\/?p=508"},"modified":"2026-06-17T11:02:31","modified_gmt":"2026-06-17T10:02:31","slug":"beyond-bmi-why-getting-measurement-right-matters-for-health-equity","status":"publish","type":"post","link":"https:\/\/research.shu.ac.uk\/shusize\/2026\/06\/17\/beyond-bmi-why-getting-measurement-right-matters-for-health-equity\/","title":{"rendered":"Beyond BMI: Why Getting Measurement Right Matters for Health Equity"},"content":{"rendered":"

I was recently featured on ITV Calendar News<\/a> (9:50 onwards) discussing concerns around Body Mass Index (BMI). As is often the case with broadcast interviews, only a short clip made it to air. But the issue deserves more space, because how we measure bodies directly shapes how we understand health -and ultimately how we care for people.<\/span><\/p>\n

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BMI is simple \u2013 but people aren\u2019t<\/h2>\n

BMI is often treated as a definitive measure of health. In reality, it\u2019s a very basic calculation: weight divided by height squared. That simplicity is both its strength and its biggest limitation.<\/p>\n

At a population level, BMI can be useful. It helps us track broad trends and understand how obesity is changing across society. When used correctly, it gives policymakers a quick, standardised way to monitor public health.<\/p>\n

But people aren\u2019t averages.<\/p>\n

When we apply BMI to individuals – particularly when we\u2019re trying to understand personal health risk or track changes over time – it becomes much less reliable. Human bodies are complex. They vary in muscle mass, fat distribution, bone density, and metabolic risk. Trying to capture all of that in a single number is, quite simply, an oversimplification.<\/p>\n

The problem is even greater across different ethnic groups<\/h2>\n

This limitation becomes even more significant when we consider ethnicity.<\/p>\n

There is strong evidence that people from Black, South Asian and some other ethnic groups are more likely to store fat around vital organs – sometimes called central adiposity. This type of fat distribution is associated with a higher risk of conditions like type 2 diabetes and cardiovascular disease.<\/p>\n

Crucially, this risk can occur at lower BMI levels than in White populations.<\/p>\n

This isn\u2019t new knowledge. It has been recognised for years by organisations such as the World Health Organization (WHO) and the UK\u2019s National Institute for Health and Care Excellence (NICE). That\u2019s why guidance recommends using lower BMI thresholds for people from these groups – typically around 2.5 kg\/m\u00b2 lower than standard thresholds.<\/p>\n

If we don\u2019t apply these adjusted thresholds, we are not measuring people accurately. And if we\u2019re not measuring properly, we can\u2019t care properly.<\/p>\n

The result? Health risks are missed, diagnoses are delayed, and existing health inequalities are widened.<\/p>\n

A recent data issue highlights the real-world consequences<\/h2>\n

These concerns have recently come into sharp focus, following a report from Nesta<\/a>. They highlighted he latest Health Survey for England (2022) – <\/em>published in 2024 – still relied on older NICE guidance that did not differentiate BMI thresholds by ethnicity. This risks systematically underestimating obesity prevalence among minoritised ethnic groups and, in turn, underestimating the true scale of health inequalities.<\/p>\n

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This example shows how small methodological decisions – like which thresholds we apply – can have very large consequences.<\/span><\/p>\n

When large groups of people are misclassified or overlooked, it distorts our understanding of population health. It also risks misdirecting resources and reinforcing inequalities that already exist within the healthcare system.<\/p>\n<\/div>\n

This is a clear example of why measurement matters – not just scientifically, but socially and ethically.<\/p>\n

Is BMI still useful?<\/h2>\n

Given all of this, a natural question follows: should we still be using BMI at all?<\/p>\n

My view is that BMI is not the future of healthcare – but for now, it remains one of the most practical tools we have at scale.<\/p>\n

It is quick, low-cost, and widely understood. That makes it valuable in large systems like the NHS, where consistency and efficiency matter.<\/p>\n

But the key is using it correctly.<\/p>\n

That means:<\/p>\n