BMI carries too much weight

The traditional measure for calculating a nation’s weight health may, according to fitness experts, have outgrown its usefulness.

The scales do not lie, or so we are told. But in the case of what constitutes being too fat, they just might be telling a few fibs, according to UAE health experts.

A new report by the World Health Organisation, says almost half of all women in the UAE are obese, as are one in three men.

Insurance provider Zurich International Life, based on a sample of 20,000 insurance applicants, says almost half of all residents are overweight, with 70 per cent of men and more than two fifths of women overweight or obese.

But UAE experts believe the figures could be misleading, because of the way they are calculated.

Both the organisations base their definitions of obesity and overweight on the Body Mass Index (BMI), a calculation that divides a person’s weight by their height squared.

For the WHO, obesity is defined as a BMI of 30 kilograms divided by each metre squared, while people with a BMI of 25 are considered overweight.

But experts in the UAE say the BMI is a superficial and redundant calculation and warn that its use can actually lead to the creation of weight problems that did not exist

This is, they say, because the BMI tells you nothing about your body composition.

“You could be 80kg and the amount of fat in your body could be, say about 40 per cent,” says Dubai nutritionist Rashi Chowdhary. “But a fitness trainer could be 85kg and the amount of fat in his body could be 10 or 15 per cent.

“The weight is the same, or probably even more, but what matters is what the weight is made up of.”

Applying BMI to children is especially “foolish”, she says.

“I actually have kids who come to me because their parents think they are overweight, because the BMI was done in school and they were asked to lose weight.

“It is actually counterproductive. It makes no sense because when you run a body-fat analysis, you see their body-fat percentage is very low.

“If you have more muscle, compared to fat, then obviously your BMI is going to be more.

“If your bone structure is better, the amount of calcium and magnesium that gets deposited on your bones is much higher, and that’s actually a very good thing.”

Ms Chowdhary says a lot of women arrive with a high BMI and might have a lot of fat to lose, but some are just heavy-boned or have more muscle.

“It’s so difficult for me to tell my clients to get off their weighing scales and not go by how much they weigh, because this is just something that we’ve grown up with, thinking: ‘Oh, this is my height, this is what my weight should be’.”

This can be dangerous, because people with low fat will end up losing muscle, mistakenly thinking they are getting healthier.

“So at best it’s foolish, at worst it’s dangerous to go by BMI.”

While Ms Chowdhary is quick to discredit the index, she does agree that there are a lot of people in the UAE with extra fat.

“I specialise in inch loss,” she says. “People come to me to lose weight and burn fat, so I see that a lot of people here do have a lot of fat to lose, subject to the amount of junk food they eat and their lifestyles.

“In a place like Dubai, one in four people are diabetic. I see kids who are 8 years old who have Type 2 diabetes. Type 2 diabetes is an adult-onset disorder. People generally get it post-40.”

She says it is obvious that people need to make lifestyle changes because, “putting it bluntly, people are fat” but using BMI is not the right way to gauge it.

Jonathan Mills, assistant general manager at Fitness First Abu Dhabi Mall says using BMI to tell if someone needs to lose weight is “pretty much a joke”.

“It’s very, very old school,” he says.

“BMI was dreamt up by a Belgian mathematician, so the guy was not even a physician. He deduced a formula to give a quick way to measure the degree of obesity of a general population, to assist the government in allocating resources.”

BMI does not provide any allowance for the relative proportions of bone, muscle and fat in the body, he says.

“Bone is a lot denser than muscle and twice as dense as fat, so a person with strong bones, good muscle tone and low fat will have a high BMI.”

Most athletes, bodybuilders and health-conscious people tend to be in the overweight

or even obese category if they go by BMI, he says. “I’m 6 foot, 5 inches and 100kg,” he says. “I’m very lean, thin and have very low body fat, but I’m classed as overweight because I’m 26 on the BMI scale.

“The reality is that I’m nowhere near overweight.

“If you’ve got a bicycle for your birthday, you can conclude that the present you got has wheels, but if you told someone that you got something with wheels as a present for your birthday, you can’t conclude that you got a bicycle, because it could have been a car.

“BMI is the exact same thing. A fat person or an obese person will have a high BMI, but a person with a high BMI isn’t necessarily going to be somoen who is overweight or obese.”

He believes that BMI would be much more accurate if it included waist measurements.

“Waist size is a clear indicator of obesity levels and that’s what I focus a lot on with my overweight clients, getting that waist size down,” he says.

Mr Mills recalls a client he had in the United Kingdom, who had been told that she could not have in-vitro fertilisation treatment until she lowered her BMI. That was “completely rubbish”, he says.

“You could see she had a bit of excess fat on her but she was nowhere near the stage where she needed to lose a lot of weight for that treatment or to be able to get pregnant.”

He says she eventually became pregnant naturally, after a change in diet and shedding a little fat.

Many people have the wrong image of their bodies, Mr Mills says, to the point where he once had a borderline-anorexic client who had been told by their doctor they had to lose weight.

“They can end up causing more problems, in terms of liver function, organ shutdown, heart problems, because if you lose too much fat you put too much stress on the heart and the liver. The body can’t function properly without sufficient fat.”

Dr Anita Das, a clinical dietician at Burjeel Hospital, does not use BMI exclusively. She factors in all considerations, including age. As people grow older, their metabolic state goes down, she says, which also pushes the top end of the normal BMI range up to 25.9. Burjeel also uses a body composition analyser on adults to gain more accurate readings of weight health. For children, they measure the triceps skin fold.

That said, Dr Das does feel there are a lot of young people in the UAE with unhealthy, sedentary lifestyles and poor dietary habits that do lead to weight issues.

“A lot of mothers who have busy lifestyles just give their children money to buy and eat what they want,” she says. “The children should be taught more about healthy eating and physical activity, instead of sitting and watching TV, or sitting at the computer and playing games.

“Even with the adults, most of them sit at a computer all day. They hardly go out. Of course, you have to take the weather into consideration, but even if people go to the mall and walk around, and go up and down the stairs, that’s nice activity.

“If they have more home-cooked food, they will know what they are adding.”