Despite being a widely-used health metric around the world, BMI measurements do not tell the full story about our health.
BMI (Body Mass Index) is worked out using a simple calculation that divides your weight by your height to work out your body fat percentage.
According to the NHS, a BMI below 18.5 is classed as “underweight”, between 18.5 and 24.9 is “healthy”, between 25 and 29.9 is “overweight” and between 30 and 39.9 is “obese”.
But the accuracy of the approach has been brought into question, not only can muscle weigh more than fat leaving very muscular people with a high BMI rating, but it doesn’t differentiate between different types of fat - some of which, such as visceral stomach fat, is more harmful to health.
Cat Lothian is just one example. She exercises regularly and yet her BMI, at 37.6, places her in the “severely obese” category.
An avid cyclist and runner, Lothian decided to explore the simple calculation that defines whether we are healthy or not.
As a photojournalism student at University of South Wales, Lothian decided to use her skills to explore the truth about BMI and scoured the country to to find active women, like her, whose BMI was above average.
“My BMI was telling me that I was very unhealthy, and I have been constantly told that I am unfit. I am a fairly active person - I horsehide, go to the gym and swim regularly, am training for a 2.5k run with my dog and have an active job,” she told The Huffington Post UK.
“I’m sick of the stereotype that fat equals unfit. I am a lot fitter than some of my peers that have a healthy weight!”
Lothian has photographed 15 subjects to date and says she was inspired by each and every one of them.
She said: “It was really wonderful watching these women train and practise, there was such a variety and I found myself wanting to try some new sports!”
While Lothian says that BMI shouldn’t be brushed off completely, she believes it is “completely flawed”.
“It doesn’t take into account muscle and bone density, ethnicity, or fat placement - it is more unhealthy to have fat in certain places than others. Someone who measures a BMI of 25.0 is considered healthy, but 25.1 is overweight and carries health warnings - that’s a couple of pounds difference!
“In my opinion, the best way to find out if your weight is healthy or not is to talk to a doctor, and use other measurements such as waist-to-hip ratio.”
Dietitian and BDA Spokesperson, Rebecca McManamon agreed. She told HuffPost UK: “BMI is not reflective of the quality of your diet, so wouldn’t reflect a healthy diet necessarily for example whether you were eating enough fruit and vegetables. It was devised by a US insurance company to calculate their risk and so is not a measure of health as such.
“Whilst a Higher BMI is linked with some cancers, heart disease and type 2 diabetes, like low BMI is associated with hormonal conditions (like periods stopping), increasing risk of infection and other illnesses; however it is not the most sensitive measure of body composition.”
McManamon added: “Women generally have a higher fat mass than men, muscle can weigh more than fat so this can distort between genders, and is also an example where if someone had a higher muscle mass due to their physical activity that they might have a BMI in say the overweight category but have a reduced risk to your health than the face value figure might suggest.”
Instead, McManamon recommends other ways to measure health: “Waist measurement and waist-to-hip ratios can be much more sensitive measures of risk to health, especially if concerned about risk of type 2 diabetes or heart disease. Whilst body composition monitors are an option, they are dependent on the amount of water in the body and so readings can vary if hydrated or not.”
[H/T The Pool]