Are YOU really too fat? You might think you’re healthy but this is the radical new way experts are deciding if you are overweight – so try our ultimate tool to discover if you need to shift the pounds

It’s not news that being overweight is bad for our health. 

Just a few extra inches around the waist has been linked to type 2 diabetes, heart problems and premature death. 

And experts now aren’t just focusing on weight to height ratio – known as body mass index or BMI. Instead, they suggest adding waist size – which would expand the number of people classed as obese by nearly 60 per cent.

Millions of Britons now may have to take fat busting jabs for life, or risk piling the pounds back on. But what about those of us who are not on the miracle injections?

To find out whether your body shape, from mass to roundness, is risking your health, input your height, weight, waist and hip measurements into our ultimate calculator.

First, it is important to understand what fat is – and when it could pose serious health risks.

If you consume more calories than you expend, your body will store them as fat. But where that fat is stored can vary massively.

That’s why experts have called for a ‘radical overhaul’ of how obesity is diagnosed, arguing that traditional BMI calculators are not ‘nuanced enough’.

Under the current rules, a BMI of 18.5 to 25 is healthy, 25 to 29 is considered overweight and 30 or above is obese – the point at which the risk or serious illness soars.

But fat, the scientists argue, can build up in people who are not typically considered overweight or obese under current guidelines, where it then collects around the mid-section.

When we put on weight, the body first stores excess calories as subcutaneous fat which sits just under the skin. For the most part, this is considered healthy fat which the body uses for energy when resources are running low.

But there’s a limit of how much subcutaneous fat we can store before it develops deep in the abdominal region and around the internal organs, known as visceral fat. 

As experts have repeatedly warned, this does not always result in a change to total weight, especially as we age and muscle mass begins to deteriorate. 

This means that despite piling on the flab, the BMI system fails to raise the alarm, leaving people unknowingly at serious risk of a number of weight-related health problems, including organ dysfunction.

Large amounts of abdominal fat, especially ‘invisible’ visceral fat that develops around organs can increase inflammation in the body, driving up blood pressure, narrowing the arteries and increasing the risk of heart attack and stroke.

Unsurprisingly, when left untreated, excess abdominal fat can be fatal. Leading experts at the BMJ found that every 10cm increase in waist circumference was linked to an 11 per cent increase risk of premature death. 

Experts say this increased risk of dying early is the result of uncontrolled blood sugar, hypertension and levels of so-called bad cholesterol in those with bigger midriffs.

Under proposed guidelines, rather than obesity being defined by a single ratio, other raised measures – such as waist circumference or waist-to-hip ratio – would be considered.

As such, someone with a BMI over 30 plus a waist-to-height ratio where their waist measurement is half or more than half of their height, would be considered obese.

The new definition was first proposed in January 2025 in a report published in the Lancet Diabetes & Endocrinology journal in a bid to tackle Britain’s spiralling obesity crisis. 

Other experts have highlighted waist-to-hip ratio as the golden measure of obesity, as a reflection of how much fat is stored within and around organs. 

To find out your hip-to-waist ratio, input your sex and measurements for your waist – your smallest point usually near the belly button – and your hips into our tool above. 

According to experts at McMaster University who spearheaded the landmark study,  a healthy ratio is 0.8 or lower for women, or 0.95 or lower for men. 

A high score is 0.86 or higher for women, or 1 for men.

Publishing their results in the journal JAMA, researchers collected measurements from over 387,600 participants and tracked their weight until they died. 

Looking at weight-related health problems including hypertension, heart disease and type 2 diabetes, the researchers concluded that waist-to-hip ratio was a better predictor of a person’s future health than BMI. 

Two in three Britons are now classed as overweight or obese, whilst NHS figures show adults weight roughly a stone more than they did 30 years ago – a trend estimated to cost the economy £100billion a year. 

But there are a number of tried-and-tested ways of losing weight. 

Cutting back on ultra-processed foods which are high in sugar and fat has been shown to result in weight loss, while 160 minutes of moderate-intensity exercise a week has been shown to have a protective effect. 

Sedentary lifestyles have also been linked with bulging waists with physical inactivity increasing the risk of obesity, which has now been linked with 13 types of cancer. 

But for most people, cutting back on calories is the answer to weight loss. 

Currently, 2.5million people are thought to be using GLP-1 weight loss jabs in the UK – which have been hailed as a breakthrough in obesity treatment. 

The jabs, including now-household names such as Mounjaro and Wegovy, work by mimicking hormones released after eating to promote feelings of fullness. 

But a major Oxford review recently suggested the benefits – from weight loss to better blood sugar control and lower blood pressure – may be short lived once treatment ends with most users regaining the weight within two years of stopping treatment. 

Professor Susan Jebb, co-author of the study and adviser to ministers and the NHS on obesity, suggested people may need a lifetime solution – such as jabs or behaviour change support or both – to tackle obesity in the long-term.