HEALTH: June 05, AU Edition

burger-pounder.jpgNOT SO FAT
New numbers from America suggest obesity isn’t as dangerous as previously thought. But don’t reach for that Big Mac just yet
Obesity is the second-leading preventable cause of death in the United States, and it’s only a matter of time before we catch up. Unless, that is, you use their newly-revised statistics, which place obesity way down at number seven in the leading preventable cause of death in the US. In which case Australia’s death rate from obesity is now almost four times higher than that of the Americans! C’mon, that can’t be right. How many fatty-fatty fat-fats are keeling over, here and abroad? I want answers – and a burger, stat!
Well, there are lies, damned lies, and statistics. There is no universal formula for working out something as complex as how many people die from diseases caused by obesity. Working out how many people die from guns is relatively straightforward. As far as I know, the leading cause of gun deaths is guns. But what about cancer? It might be related to obesity, but the obesity isn’t required for the cancer. Skinny people die of heart disease, as do the, ahem, big-boned. If someone has a heart attack and dies, and is also overweight, there may be correlation. But since we know that skinny people have heart attacks too, how do we know if their chubbier cousin would have died of a heart attack anyway, irrespective of his weight?
To use the example of the Australian state of Victoria, their “Burden of Disease” statistics show that in 2002, 650 overweight or obese people died from cardiovascular disease, 450 from type-two diabetes and 300 from cancer. Catch the trick? That’s how we get our statistics down under. If a fat person dies from something that can be related to excess weight, it’s an obesity- related death. No statistics are available on how many of those people might have died anyway.

An example: Let’s suppose that one of those people was called Dazza. Dazza had a heart attack at a family barbie and died in rural Victoria died in 2002. At the time of his death he had three charred steaks, mounds of potato salad and eight or nine beers on board. He also snuck off behind the shed and had five or six Winnie Blues with his brother, but his wife didn’t catch him, so they don’t count. Always the clown, when old Daz grabbed his chest and fell down, it was six minutes before “get up, ya retard” turned to panic. The ambulance took fifteen minutes to arrive. Now although Dazza died of a heart attack, his passing also counts as a weight-related death and a tobacco-related death. Of course, the delay in treatment contributed. Having a father and two uncles who died of heart attacks before 50 also contributed. Now if Dazza died at 65, he’s doing well, compared with his ominous family history. The statistics fail to take these nuances into account.
The US Centers for Disease Control and Prevention estimated in April 2005 that too much weight accounted for 25,814 deaths a year in the United States, 14 times less than their January estimate of 365,000 deaths. Now the same number of people died, and the same number were overweight or obese. What the CDC did to get the new figures was to improve their statistical analysis. They took into account a range of factors, some of which may seem surprising.
Much of the problem comes from the use of the Body Mass Index, or BMI. You can easily calculate your Body Mass Index, which is your weight in kilograms (kg) divided by their height in meters (m) squared. So if I am 178 cms tall (from memory) and 59 kgs (distant memory), my BMI is 59  1.782, which makes 18.62 and places me at the low end of the healthy weight range (BMI of 18.5 – 25). If you are very fit (muscular), under 18, experiencing the effect of age (losing muscle), or pregnant, the BMI may not be accurate. The World Health Organisation also recommends different cut offs for south-east Asians, so if your genetic heritage is such, the BMI may not be accurate. If you have recently had a baby, you should substitute the lowest weight you’ve ever been for your actual weight, as I did (just for fun).
Generally 25-30 is considered overweight, and over 30 is considered obese. Further confusing the matter, the cut-off may change between countries and over time. For example in 1998 the US National Institute of Health changed their cut-off for “overweight” from BMI 27.8 to BMI 25. 30 million Americans, previously “technically healthy” became overnight “technically overweight”.
With limited variations this is how the statistical bodies know if you’re an obesity or weight-related death. Because of the limitations of the BMI I prefer the LBM assessment (Look in the Bloody Mirror). It should be abundantly clear (unless you have a body image disorder) whether you are healthy, overweight or obese. And I have to say, being obese is defiantly not good for you, there aren’t two ways about it. It will put you at risk for a lot of things (cancer, heart disease) that will shorten your life (you’ll die). More so than if you were trim and terrific. If you are merely overweight, however, it’s not so clear.
How many people do you know (often women, but not always) who go to the gym, swim twice a week and do yoga on Saturdays and are still “big boned”? They probably have good muscle tone from the exercise, but you may not see it for the soft curvaceous coating. I personally spend a good deal of time participating in toddler aerobics and I believe you could bounce a penny off my “abs”. If you could find them under the squishy layer of stored energy, which you can’t. So if people are overweight, are they automatically at risk of overweight related death?
A study in 1996 confirmed earlier research which showed that for adults over 35 attempted weight loss is associated with lower all-cause mortality, regardless of whether or how much weight is lost. So trying to loose weight is beneficial for your health, even if you don’t loose weight. It’s common sense: an overweight person who works out and eats well should be much healthier than a lazy, unfit, skinny person. Fitness generally seems to mean cardiovascular fitness, which is achieved through cardiovascular exercise, which leads to a healthy heart. If you happen to exercise until you can talk, but not easily (a useful rough definition of effective cardiovascular exercise) for 40 minutes at a time 3 times a week, you should know for yourself that you are healthy. You may, however, still be overweight.
Have a look at the people in your family. Scientists have not yet discovered the gene that causes a craving for breakfast at McDonalds, but they have discovered a small number of genes for obesity. And there are probably more. As in all things, some people are better at some things than others, even at a physiological level. Some people don’t get enough iron in their diet, but their body is very good at using what they get, and they just never get anaemic. Some people are just efficient fat burning machines, eat badly and do no exercise yet stay skinny. Not healthy, mind you, just skinny. Some people just have a hard time losing weight, but if they are doing all the right things, they could well be healthy. If a 10-metre sprint for the bus leaves you breathless, I don’t care how you look, your health is in trouble.
You can be fit but overweight if you try because for all the books on weight loss out there, the whole thing is simpler than you’d think. If the energy you take on is more than the energy you expend, you gain weight. You burn calories/ kilojoules/energy (synonyms for popular purposes) all the time, to breath, to sleep – perchance to dream – to walk to the shop. And you intake energy all the time. If it’s not water and it goes in your mouth to your stomach, it counts as energy.
The more energy you expend (all common sense; walking burns more energy than watching TV etc) the more energy you burn. You could get fat eating apples if you ate a lot of them and moved as little as possible. So if you are overweight, you need to eat less or exercise more. Of course, if you exercise more, you will be fit, which is good. If you just eat less, you could be skinnier but no healthier.
Bottom line, fitness counts for more than weight. We don’t really know how many “overweight and obesity related” deaths happen. I’m not sure what it matters. Being overweight may cause (indirectly) death, being unfit is a better target.
We shouldn’t (alas we do) judge this on how you look. It doesn’t matter what the stats are, I tell you this; if you can’t run for the bus, you’re in trouble.