From The Urbach Letter –
Your BMI? Do You Know?
We Americans know our personal health numbers: our weight to the pound, our blood pressure, our cholesterol, and so on. But most people don’t know their Body-Mass-Index (BMI). You should. It’s a very important number. BMI is based on both your body weight and your height, and can guide you to a healthy weight level for your body type. Unfortunately, BMI is a bit tricky to calculate: (your weight in kilograms divided by your height in meters squared), but as usual, clever people have designed a nice free resource you can click on for the answer. There are many BMI calculators on the web but the best I've found is Hall's BMI Calculator. Once you determine what your BMI is now, consult this chart to see if you’re in the normal range:
Most folks these days tend to fall in the high end of the range. If you do, you might consider how you’re going to improve your number. Since BMI is a function of weight divided by height, you have two options to lower it: (A) get taller, or (B) lose some weight. If you’re a full grown adult, there’s not too much you can do about "A." Fortunately, there’s a lot you can do about how much you weigh. Once you get over the fantasy of fast and easy weight loss (promulgated by unethical advertisers and overzealous book promoters), and commit to making some real, positive changes in your lifestyle, you will lose weight and you will keep it off. The ONLY way to significant and permanent weight loss is a lifestyle change.
You must simultaneously reduce the total number of calories you consume each day and increase your activity level. If you believe there’s any other way, you are mistaken. Fortunately (for most people) we’re not talking about drastic changes. You don’t have to subsist on sprouts and rice cakes and spend hours in a gym every day. Normal people can’t do that… at least not for very long. However, you can pass on the chips, refuse the second helping, drink more water, take the stairs, and walk everywhere you can. You get the idea. You must be consciously committed to this – otherwise you’ll slip back to your old ways (I’ve been there). However, with desire and commitment, you *will* reach your goal. I did. I reduced my BMI from 27.7 to 22.5. You can too.
Need more motivation? A new study published last week in the British scientific journal Proceedings, shows that the right BMI number is an authoritative measure of a woman’s attractiveness. Researchers from the University of Newcastle found that “vital measurements” (bust, waist, hips) are not as important as whether a woman’s weight looks right for her height. Similar results are expected for men too. The researchers noted that having a BMI between 20 and 25 indicates healthiness (“looking fit”) and therefore attractiveness. It should come as no surprise that successful female fashion models then to fall within a narrow BMI range (the low end of the range, of course). However, like many things, going to extremes can have negative consequences. A reproductive expert quoted in Shape Magazine states that a BMI under 20 is associated with reduced fertility, as is a BMI of 28 or higher. Below 17 or above 30, fertility is significantly reduced – because too much body fat (or too little) can disrupt hormonal levels. The magazine recommends keeping your BMI between 20 and 27 for “best baby-making success.”
Here’s another reason to move yourself more into the normal range: Weight loss expert and medical doctor S.B. Halls states that if your BMI is between 17 and 22, your lifespan may be longer than the average (because you’re less likely to die from coronary artery disease or cancer). If your BMI is 25 or higher, you are considered overweight, and are statistically likely to have a reduced life expectancy -- that is, more likely than the average person to have a heart attack or stroke, get cancer, develop diabetes, or succumb to other serious disease.
One final note: while it’s far superior to the old fashioned height and weight charts, BMI may overestimate body fat in athletes and people with muscular builds, and underestimate it in older people (who may have lost some muscle mass).