How Relevant Is BMI
This interesting research was sent to me by a colleague raising question as to the usefulness and validity of the BMI to predict health. Read on…….
http://suewidemark.com/fat-fit-new.htm - this has some very basic data. His research is about how BMI is irrelevant, that they looked at cardiovascular health and age at death to determine “health.” In all cases, across weight levels, they found that physical fitness was key. They even looked at people who are considered morbidly obese, and those that were physically fit and morbidly obese had lower rates of heart disease and greater longevity than “average” weight people who were unfit. Fitness was measured by stress tests they gave at the Institute.
Fit and Fat
by Steven Blair, Miavita Scientific Advisor
Most people think that you can tell if someone’s fit, active and healthy just by looking at them. It’s not true! Fit, healthy people come in all sizes and shapes. The same is true of unhealthy people. I know several thin people who are unfit and have serious health problems. Weight Isn’t Everything.
How is it possible to be fat and fit?
Quite simple. You may have the genetic predisposition to be “stocky,” yet you engage in regular exercise. A colleague once asked a 5′ 4″, 200-lb. woman how she viewed her weight despite routinely devoting an hour a day to vigorous exercise. She replied, “I used to weigh 100 pounds more than I do now.” In terms of her health, that’s a tremendous difference. I often tell people that I was short, fat and bald when I started running, but that after running nearly every day for more than 30 years and covering about 70,000 miles…I am still short, fat, and bald. But I suspect I’m in much better shape than I’d be if I didn’t run.
Fitness = Longevity:
For much of my career, I’ve tracked a large group of patients from the Cooper Clinic. Each individual received a medical examination upon entering the study, including measurements of height, weight, body composition and cardiorespiratory fitness. We have followed these patients over the years to see who gets sick, who stays healthy, who lives and who dies. The results are fascinating.
Our follow-up has shown that the death rate for women and men
who are thin but unfit is at least twice as high as their obese counterparts who are fit.
In fact, across every category of body composition, unfit individuals
have a much higher death rate than those who are fit.
Fitness appears to provide protection against early mortality
no matter how much you weigh.
Defining Fitness:
Being fit, as defined in our study, does not require high-level athletic training. It means meeting the consensus public recommendation of a cumulative 30 minutes of moderate intensity daily activity, such as walking. Doing more brings additional health benefits. Overall, our data show about 50% lower mortality in the moderately fit as compared with the low fit; highly fit individuals lower their risk another 10 - 15%.
Another interesting finding:
Many people classified as obese by current standards actually have a good health profile. We see that as many as 40% of obese individuals have normal cholesterol and blood pressure, do not smoke and are physically fit. Anyone who struggles with their weight should take this as good news.
My recommendation is to focus on good health habits, no matter what number
you see on the scale. Give fruits, vegetables and whole grains a major place
in your daily diet. Be moderate about fat and alcohol. Don’t smoke.
Work on managing stress. Perhaps most important, get out
of your chair and start moving for at least 30 minutes every day.
Steven Blair is the Director of Research at the Cooper Institute for Aerobics Research in Dallas.