The Body Mass Index is a popular way to measure and assess whether someone is overweight or underweight. Basically, it's just your weight divided by your height. BMI is a simple system, but it does have some flaws. Over at the Obesity Panacea blog, Peter Janiszewski (who has a Ph.D. in exercise physiology) has a nice post explaining why BMI is sometimes useful, and also why it's not a great measurement of individual health.
Right now, I bet you're chomping at the bit with, "Yeah! The BMI doesn't distinguish between fat and muscle!" And you're right. It doesn't. A simple BMI measurement would tell you that The Rock is no different than an out-of-shape couch potato of the same height and weight. Obviously, that's a flaw in the system. But it's not the most important flaw, Janiszewki argues. In fact, he says, this well-known problem with BMI is the easiest one to work around. A simple visual check can tell your doctor whether your high BMI is due to excess muscle or excess fat.
The real problems with BMI, he says, are a lot more complicated. For one thing, the system doesn't distinguish between very real differences in health outcomes for different body types. "Pears" and "Apples" might have the same BMI, but with opposite health results. Even more troubling: You can change your lifestyle, and become objectively healthier, and your BMI might not budge.
This is particularly so if you adopt a physically active lifestyle, along with a balanced diet, but are not necessarily cutting a whole lot of calories. This lack of change in BMI or body weight is all too often interpreted as a failure, resulting in the disappointed individual resuming their inactive lifestyle and unhealthy eating patterns.
However, as we have argued most recently in a paper in the Canadian Journal of Cardiology, several lines of evidence suggest that weight loss or changes in BMI are not absolutely necessary to observe substantial health benefit from a healthy lifestyle. Thus, an apparent resistance to weight-loss should never be a reason for stopping your healthy behaviours.
Read the rest at Obesity Panacea
Image: Wisley Taste of Autumn: Europom, a Creative Commons Attribution (2.0) image from rictor-and-david's photostream
Despite Trump’s denial of climate change the the ghastly attacks on climate science and mitigation in the new proposed budget, the Carbon Bubble — which overprices hydrocarbons and the industries that rely on them, as though we’ll be burning all of them with impunity — is about to pop.
South American polka dot tree frogs are pretty cool, but Julián Faivovich and Carlos Taboada found out they are even cooler when an ultraviolet flashlight is trained on them. They fluoresce. Many animals can see beyond the spectrum visible to humans, and these frogs adapted with this trait. From the abstract: Fluorescence, the absorption of […]
A small (51 men aged 24 +/- 3 years) study published in Neuron tasked experimental subjects with practicing the ancient Greek mnemonic technique of “memory palaces” and then scanned their brains with functional magnetic resonance imaging, comparing the scans to scans from competitive “memory athletes” and also measuring their performance on memorization tasks.
The Lightning port has thus far resisted the cruel fate that befell the headphone jack, and despite rumors that it may be disappearing come iPhone 8, for the present and foreseeable future, Lightning cables are a hot commodity for iPhone users. As such, we must make do in this strange time in which long, glorified […]
All the filters in the world won’t save your smartphone pics from a shaky hand. To really step up your mobile photography game, you’ll need some kind of mount to hold it steady. You could buy a smartphone attachment for a conventional camera tripod, but who wants to carry that kind of gear everywhere they […]
The forced transition from analog to digital TV signals was probably met with relative indifference from people with Netflix subscriptions and the “I don’t even own a TV” snoots. But anyone living in the vast swaths of the country that don’t have guaranteed high-speed internet, broadcast TV is a perfectly valid (and 100% free) way […]