From my own experience, I’d think the BMI is a crock too. At one point a few years ago, I was down to 152 pounds (on a 6’2" frame). That would make my BMI 19.5, just below normal. But anyone who saw how my ribs, shoulder blades and spine were jutting out could have told you how far away from “normal” I was. For taller folk, BMI just doesn’t seem to work right.
But that’s Opinion. How 'bout some factual, or lack-of-fact, skepticism? The CDC claims that BMI may be a useful measure, but, on the same page that DarrenS links to, they hedge wildly:
So, in other words, the CDC really isn’t sure if BMI is useful or not, after all. You’d think this warranted a little bit more research, no?
One last thing all you’ve missed here, though. Female breasts are “not mainly fat,” according to many researchers, who say they are typically comprised of 80 percent glandular tissue and about 20 percent fat. The Master speaks.
I don’t think any doctor thinks of BMI as more than a rough tool. It is not infallible.
No convincing some people, but here are the facts.
Various definitions of “overweight” and “obesity” are used.
An expert US panel defines overweight as a BMI between 25 and 29.9, and obesity as a BMI over 30 (Arch Intern Med 158:1855-67,1998.)
In Canada, obesity has been defines as a BMI over 27 (CMAJ, 160:513-525, 1999.)
Another measure of obesity is a waist to hip ratio above 0.95 in men or 0.80 in women (BMJ 311:158-161,1995). Women above 0.75 have twice the risk of coronary artery disease than those with a low ratio (JAMA 280:1843-8, 1998).
Abdominal girth of greater than 50 inches in men and 35 inches in women are considered dangerous (BMJ as above).
The prevalence of obesity increased in the US from 12% in 1991 to 18% in 1998 in both sexes, all age groups and education levels; more so in Hispanics, those in their twenties and the college educated (JAMA 282:1519-22,1999).
Complications of obesity (souces on request only) include hypertension, coronary heart disease, type 2 diabetes, gallbladder, sleep apnea, respiratory problems, osteoarthritis, cancers of the breast, endometrium, prostate, colon and pancreas; low back pain, increased total mortality, increased complications during pregnancy.
Increasing BMI has been linked progressively to increased risk of coronary artery disease. Women with a BMI greater than 29 have 3.5 times the risk as a woman with BMI less than 21. (JAMA 273:461-5, 1995). This also applies to men (BMJ 314:1311-17, 1997).
Total cohort mortality increased sharply in women with a BMI over 27 (JAMA as in the paragraph above) and men over 30 (BMJ as above). This was also increased in gaining more than 10 kilograms since age 18 even if the weight is still within a normal limit (JAMA as above).
The CDC is not hedging wildly. The fact two people with the same BMI have differing chances of CAD depends not just on fat, or BMI; but also other proven risk factors: male sex, family history, smoking, obesity, hypertension, physical activity, diabetes, elevated LDL cholesterol and low HDL cholesterol. (JAMA 277:1387-90, 1997). As above, BMI has been strongly linked to heart disease. An understanding of statistics would show that what applies to a cohort does not apply to every individual.
The biggest risk factor in heart disease is being human. The most common cause of death for men and women with NONE of the above risk factors is heart disease. (Ann Med 21:409-13, 1989).
The BMI is a useful clinical tool for recommending and monitoring weight loss in patients.
It is less useful in determing your “ideal” weight. If you are close to the recommended 20-25, that is good enough. Your pathetic whining about how your 19.5 or 26 score doesn’t apply to you can be answered thusly:
it probably does
if it doesn’t apply to you, that does not make it a useless measure
it has been strongly linked to risk of heart disease
since everyone is at risk for heart disease, people who reduce known risk factors live longer, even though people with no risk factors also die of heart disease
any tool or test requires clinical interpretation; many people with gout have normal uric acid levels, for example
When I was in undergrad, I was teaching Tae Kwon Do two nights a week, really flexible, but I ate terribly. I drank four nights a week and I ate 4 large pizzas a week on top of the other crap that I eat. Vegetables and fruits were rare, if they weren’t attached to a hamburger or a pizza. I’m 6’ and about 195 lbs at my highest. I had pretty good endurance, too (try sparring 2 hrs/wk and 3 sessions of 100 speed kicks, each leg). My waist was about 33-34 inches (varied).
After college, I started training for marathons. My waist size didn’t change, I lifted weights 3x’s/wk and I still ate bad. I went down to 185 lbs. Later, I went to Europe to study, took a break and backpacked for 3 weeks (walked everywhere), eating sparringly (real meal was dinner, drank 1.5 litres of water at least daily) and when I got back I was down to 167 (that didn’t last long). My waist felt thinner, but there was fat on it. It doesn’t hang over my belt (it never did/does), but I didn’t have a 6 pack (maybe 4 at best).
Now, I pulled my hamstring and all I do is ride my bike and lift. I eat super healthy b/c I don’t want to get fat. I eat 4-6 times/day (depending on how busy I am), with a little fat, little carbs, and a lot of protien. I’m not as flexible, b/c it still hurts a little to stretch my hamstring. I eat a salad everyday and two large pieces of fruit. I’m starting to get into meal replacements (I’ll post about that later). However, I am stronger than I’ve ever been before. My waist size is 32-33, and depending if I just ate lunch, I’m somewhere b/t 200-205 lbs. I can max press (3x’s) 265 lbs no spotter. I can pinch an inch on my stomach, but everywhere else is taut. Am I fat? My BMI is 27.1, and my face looks rounder than before (double chin?)
My own personal experience - I’m 6’2", 205 lbs. My stomach looks more like a keg than a six-pack; I’m definitely not a muscle man. I recently took a body fat test at a gym, and the results were that I was well within the healthy range. They also told me how much of those 205 lbs was fat. I checked the body mass index, and the result was that to get into the middle of the “healthy” range, I would have to lose all my body fat. That is definitely not a healthy thing to attempt. I suppose it may work for “average” people - but it doesn’t do much to tell you if you’re average.
My own personal experience - I’m 6’2", 205 lbs. My stomach looks more like a keg than a six-pack; I’m definitely not a muscle man. I recently took a body fat test at a gym, and the results were that I was well within the healthy range. They also told me how much of those 205 lbs was fat. I checked the body mass index, and the result was that to get into the middle of the “healthy” range, I would have to lose all my body fat. That is definitely not a healthy thing to attempt. I suppose it may work for “average” people - but it doesn’t do much to tell you if you’re average.
YES, bmi is bullshit BUT at 5’2" you should really be even less, more like 110 lb
real indicator is bodyfat percentage ( BF% ). to be sexy for a man is about 6% for woman about 10%
on other hand, an “average healthy” BF% is about 15% for both men and women and thats about where the BMI will land you, except that BMI does not account for the fact that people have different sized frame, musle etc … and BF% automatically handles all that.
btw, bodybuilder in contest shape is 2% bodyfat. thats when all the veins stand out on your skin and the muscles all look striated, even glutes ( ass ) .
The BMI does not determine sexiness. It is not meant to give a bodyfat percentage. What it shows is that high BMIs are correlated to dying from heart disease. That’s it. And the studies include people with high BMIs because they are fat, as well as high BMIs because they are fit or stacked.
My BMI is 28. In Canada, that makes me “obese”. I’ve bench pressed 300 lbs and could squat far more. But even if I don’t think I am obese, having the elevated BMI still puts me at increased risk of dying from cardiac disease.
Based upon his commentary on the topic of weight in other threads, vasyachkin simply has no clue. (At least here there’s an attempt to look scientific, as opposed to his usual tactics of fatbashing and namecalling.)
A woman needs a specific amount of bodyfat (called essential bodyfat) to remain healthy – fat stores in breasts, pelvis, hips and thighs should be closer to 15% for the average reproductive-aged woman who does not wish for her health to be compromised, especially her reproductive health. A woman with only 10% bodyfat is unlikely to be physically capable of menstruating.
The American Council on Exercise has created the following guideline:
Classification Women (% Fat) Men (% Fat)
Normal 15-25 percent 10-20 percent
Overweight 25.1-29.9 percent 20.1-24.4 percent
Obese Over 30 percent Over 25 percent
Dr_Paprika, you’ve contradicted yourself. If BMI is only a rough tool, the measures of which are only applicable to those who fall within an “average” category, how can you categorically state that having an elevated BMI is, in and of itself, an indication of an increased risk of death from cardiac disease? Seems just a touch overbroad.
I may not be Dr_Paprika but I’ll take a stab at the question - ANY risk factor for cardiovascular problems puts you at a higher risk of cardiac death. That’s why it’s a risk.
As an example - suppose you had someone who is diabetic, but is a pro athelete (there are some, you know). Even if this person lived on the Dean Ornish diet (known to reduce cardiovascular problems), had ideal blood pressure, ideal cholesterol, ideal bodyweight, ideal body fat percentage - in other words, they were the picture of health outside of their diabetes - they would STILL be at an increased risk of heart disease and death from cardiovascular problems. Now, because they’re taking such great care of themselves otherwise their overall risk of such a death may be lower than that of some overweight, couch-potato, crap-eating person, but that does not eliminate the fact that our hypothetical diabetic athlete still has a known risk factor for cardiac problems.
Another example might be someone extremely fit, eating properly, low body fat, etc but who has elevated blood pressure. Even if all other indicators are good, the high blood pressure is STILL a risk factor for cardiovascular problems and will put them at a higher risk of stroke.
Virtually everyone to one degree or another is at risk for heart disease. The best you can do is minimize your risk. So… if you do tend to carrying more weight than average then it’s important to exercise, keep your blood pressure under control, and otherwise reduce all the potential cardiac risks in your life, even if you can’t elminate them. Simply losing a lot of weight isn’t going to help much if you don’t deal with all the other risk factors in your life.
An elevated BMI has been shown to be a risk factor for death of cardiac disease, even after taking into account all the other known and putative risk factors for heart disease – including diabetes, high blood pressure, etc.; the cites are above.
BMI is a rough tool for defining “obesity”, but that does not mean that having an increased BMI doesn’t increase your risk of heart disease; the studies suggest otherwise.
That being said, you could easily have a higher BMI than someone else. They could die of heart disease and you might not. Applied to individuals, it’s a question of relative risk.
Broomstick did an excellent job of summarizing the role of risk factors.
Increasing BMI has been linked progressively to increased risk of coronary artery disease. Women with a BMI greater than 29 have 3.5 times the risk as a woman with BMI less than 21. (JAMA 273:461-5, 1995). This also applies to men (BMJ 314:1311-17, 1997).
Total cohort mortality increased sharply in women with a BMI over 27 (JAMA as in the paragraph above) and men over 30 (BMJ as above). This was also increased in gaining more than 10 kilograms since age 18 even if the weight is still within a normal limit (JAMA as above).
I might have said one point more clearly; some doctors use BMI to define obesity (e.g. BMI over 30 in the U.S.). BMI is a rough tool that requires clinical correlation, though. Saying your individual ideal weight must be a BMI between 20-25 might be taking things too far. Saying high BMIs increase cardiac risk is not taking things too far. Studies can control for factors like diabetes, high blood pressure, etc. A relative risk of 3 is pretty dramatic, even if there were minor flaws or biases in a study.
However, as has been noted, having a high BMI is not always an indication of being overweight or even obese. A quick run through the rosters of the Washington Wizards and the Pittsburgh Steelers picks up a large number of BMIs over 25, and in the case of the Steelers, a couple over 30. Running back Jerome Bettis ranks in at about a 35. Yet anyone who has seen Jerome Bettis can tell you unequivocally that he is by no means obese, and given his physical conditioning it seems out of place to say that he is at higher risk of death from cardiac complications because he is more densely muscular than average in relation to his height.
And therein is my point – while BMI can be a general indicator of an overweight condition based upon excessive bodyfat, that’s not always the case. It may seem nitpicky, but it seems more appropriate to say that a high BMI due to excess bodyfat increases risk, or to not put so much stock into such an admittedly rough measure when talking about something as serious as cardiac risk at all, sticking instead to measures like bodyfat and fat distribution.
im screwed with the BMI. im 6’0", 261 lbs and a 3 point caliper bodyfat test says i am roughly 16% bodyfat (i think thats low though). i haven’t done any bioelectrical tests but i would think they’d put me at about 21% or so. There is no way in hell i can ever approach my recommended weight which is roughly 170 lbs.
