Why the BMI May Be a Flawed Measure of Health

The body mass index, or BMI, may not be an accurate indicator of a person's risk of heart disease or diabetes, according to a new study.
The results suggest that about 75 million adults in the United States may be misclassified — they have a true risk of heart disease or diabetes that is either lower or higher than suggested by their BMIs, the researchers said.
The new results show that BMI is a flawed measure of health, they said.
To stay healthy, people should "prioritize eating well, staying aactive and getting enough sleep," rather than focus on their weight, said study co-author Jeffrey M. Hunger, a doctoral candidate at the University of California, Santa Barbara.

In the study, the researchers looked at the BMIs of about 40,000 adults in the U.S. They also looked at data on the people's "cardiometabolic health," which is their risk for heart disease and diabetes, including data on their blood pressure, blood sugar, cholesterol, inflammation and insulin levels. According to the definition adopted by the researchers, a person "is considered cardiometabolically healthy only if they have healthy values on four or more of these indicators," Hunger told Live Science.

When the researchers looked at the relationship between the people's BMIs and their cardiometabolic health, they found that nearly half of the people with a BMI in the overweight range, 29 percent of people with a BMI in the obese range and 16 percent of very obese people were cardiometabolically healthy. [Best BMI Calculator Apps]

"Many people see obesity as a death sentence," lead study author A. Janet Tomiyama, an assistant professor of psychology at the University of California, Los Angeles, said in a statement. "But the data show there are tens of millions of people who are overweight and obese and are perfectly healthy."

In addition, more than 30 percent of the people whose BMIs were considered in the normal weight range were found to be cardiometabolically unhealthy.

Previous research has also suggested that using BMI as a measure of health may be problematic. For example, a study published in 2010 in the International Journal of Obesity found that waist size was a better predictor than BMI of kids' future risk of heart disease. And another study, published in 2014 in the journal Pediatric Obesity, found that 25 percent of kids who were obese based on their body fat content were not labeled as obese based on their BMI.

The new study was published today (Feb. 4) in the International Journal of Obesity.



http://www.livescience.com/53612-bmi-may-not-reflect-peoples-health.html



Interesting this has come up after that debate on the mother and daughter a while back.
Nor surprised at the findings

BMI lost its status as a health indicator when people realised that people with a high muscle proportion can also have a BMI greater than 25. 

And besides, it had no real meaning. 

Waist to hip ratio people can understand and is a decent indicator of health, esp. When you don't have facilities to check for inflammation. 

Body fat % is prob the best way for they laymen to use a health index.

Ahhh. Scientists and the "experts" change their minds again....

There seem to be no such thing as "facts" anymore

eddie wrote:Ahhh. Scientists and the "experts" change their minds again....

There seem to be no such thing as "facts" anymore

BMI was invented by a mathematician Eddie, so not a scientist.


Also



Misinterpretations of the scientific process

MISCONCEPTION: Science is a collection of facts.

CORRECTION: Because science classes sometimes revolve around dense textbooks, it's easy to think that's all there is to science: facts in a textbook. But that's only part of the picture. Science is a body of knowledge that one can learn about in textbooks, but it is also a process. Science is an exciting and dynamic process for discovering how the world works and building that knowledge into powerful and coherent frameworks. To learn more about the process of science, visit our section on How science works.

MISCONCEPTION: Science is complete.

CORRECTION: Since much of what is taught in introductory science courses is knowledge that was constructed in the 19th and 20th centuries, it's easy to think that science is finished — that we've already discovered most of what there is to know about the natural world. This is far from accurate. Science is an ongoing process, and there is much more yet to learn about the world. In fact, in science, making a key discovery often leads to many new questions ripe for investigation. Furthermore, scientists are constantly elaborating, refining, and revising established scientific ideas based on new evidence and perspectives. To learn more about this, visit our page describing how scientific ideas lead to ongoing research.

MISCONCEPTION: There is a single Scientific Method that all scientists follow.

CORRECTION: "The Scientific Method" is often taught in science courses as a simple way to understand the basics of scientific testing. In fact, the Scientific Method represents how scientists usually write up the results of their studies (and how a few investigations are actually done), but it is a grossly oversimplified representation of how scientists generally build knowledge. The process of science is exciting, complex, and unpredictable. It involves many different people, engaged in many different activities, in many different orders. To review a more accurate representation of the process of science, explore our flowchart.

MISCONCEPTION: The process of science is purely analytic and does not involve creativity.

CORRECTION: Perhaps because the Scientific Method presents a linear and rigid representation of the process of science, many people think that doing science involves closely following a series of steps, with no room for creativity and inspiration. In fact, many scientists recognize that creative thinking is one of the most important skills they have — whether that creativity is used to come up with an alternative hypothesis, to devise a new way of testing an idea, or to look at old data in a new light. Creativity is critical to science!

MISCONCEPTION: When scientists analyze a problem, they must use either inductive or deductive reasoning.

CORRECTION: Scientists use all sorts of different reasoning modes at different times — and sometimes at the same time — when analyzing a problem. They also use their creativity to come up with new ideas, explanations, and tests. This isn't an either/or choice between induction and deduction. Scientific analysis often involves jumping back and forth among different modes of reasoning and creative brainstorming! What's important about scientific reasoning is not what all the different modes of reasoning are called, but the fact that the process relies on careful, logical consideration of how evidence supports or does not support an idea, of how different scientific ideas are related to one another, and of what sorts of things we can expect to observe if a particular idea is true. If you are interested in learning about the difference between induction and deduction, visit our FAQ on the topic.

MISCONCEPTION: Experiments are a necessary part of the scientific process. Without an experiment, a study is not rigorous or scientific.

CORRECTION: Perhaps because the Scientific Method and popular portrayals of science emphasize experiments, many people think that science can't be done without an experiment. In fact, there are many ways to test almost any scientific idea; experimentation is only one approach. Some ideas are best tested by setting up a controlled experiment in a lab, some by making detailed observations of the natural world, and some with a combination of strategies. To study detailed examples of how scientific ideas can be tested fairly, with and without experiments, check out our side trip Fair tests: A do-it-yourself guide.

MISCONCEPTION: "Hard" sciences are more rigorous and scientific than "soft" sciences.

CORRECTION: Some scientists and philosophers have tried to draw a line between "hard" sciences (e.g., chemistry and physics) and "soft" ones (e.g., psychology and sociology). The thinking was that hard science used more rigorous, quantitative methods than soft science did and so were more trustworthy. In fact, the rigor of a scientific study has much more to do with the investigator's approach than with the discipline. Many psychology studies, for example, are carefully controlled, rely on large sample sizes, and are highly quantitative. To learn more about how rigorous and fair tests are designed, regardless of discipline, check out our side trip Fair tests: A do-it-yourself guide.

MISCONCEPTION: Scientific ideas are absolute and unchanging.

CORRECTION: Because science textbooks change very little from year to year, it's easy to imagine that scientific ideas don't change at all. It's true that some scientific ideas are so well established and supported by so many lines of evidence, they are unlikely to be completely overturned. However, even these established ideas are subject to modification based on new evidence and perspectives. Furthermore, at the cutting edge of scientific research — areas of knowledge that are difficult to represent in introductory textbooks — scientific ideas may change rapidly as scientists test out many different possible explanations trying to figure out which are the most accurate. To learn more about this, visit our page describing how science aims to build knowledge.

MISCONCEPTION: Because scientific ideas are tentative and subject to change, they can't be trusted.

CORRECTION: Especially when it comes to scientific findings about health and medicine, it can sometimes seem as though scientists are always changing their minds. One month the newspaper warns you away from chocolate's saturated fat and sugar; the next month, chocolate companies are bragging about chocolate's antioxidants and lack of trans-fats. There are several reasons for such apparent reversals. First, press coverage tends to draw particular attention to disagreements or ideas that conflict with past views. Second, ideas at the cutting edge of research (e.g., regarding new medical studies) may change rapidly as scientists test out many different possible explanations trying to figure out which are the most accurate. This is a normal and healthy part of the process of science. While it's true that all scientific ideas are subject to change if warranted by the evidence, many scientific ideas (e.g., evolutionary theory, foundational ideas in chemistry) are supported by many lines of evidence, are extremely reliable, and are unlikely to change. To learn more about provisionality in science and its portrayal by the media, visit a section from our Science Toolkit.

MISCONCEPTION: Scientists' observations directly tell them how things work (i.e., knowledge is "read off" nature, not built).

CORRECTION: Because science relies on observation and because the process of science is unfamiliar to many, it may seem as though scientists build knowledge directly through observation. Observation is critical in science, but scientists often make inferences about what those observations mean. Observations are part of a complex process that involves coming up with ideas about how the natural world works and seeing if observations back those explanations up. Learning about the inner workings of the natural world is less like reading a book and more like writing a non-fiction book — trying out different ideas, rephrasing, running drafts by other people, and modifying text in order to present the clearest and most accurate explanations for what we observe in the natural world. To learn more about how scientific knowledge is built, visit our section How science works.

MISCONCEPTION: Science proves ideas.

CORRECTION: Journalists often write about "scientific proof" and some scientists talk about it, but in fact, the concept of proof — real, absolute proof — is not particularly scientific. Science is based on the principle that any idea, no matter how widely accepted today, could be overturned tomorrow if the evidence warranted it. Science accepts or rejects ideas based on the evidence; it does not prove or disprove them. To learn more about this, visit our page describing how science aims to build knowledge.

MISCONCEPTION: Science can only disprove ideas.

CORRECTION: This misconception is based on the idea of falsification, philosopher Karl Popper's influential account of scientific justification, which suggests that all science can do is reject, or falsify, hypotheses — that science cannot find evidence that supports one idea over others. Falsification was a popular philosophical doctrine — especially with scientists — but it was soon recognized that falsification wasn't a very complete or accurate picture of how scientific knowledge is built. In science, ideas can never be completely proved or completely disproved. Instead, science accepts or rejects ideas based on supporting and refuting evidence, and may revise those conclusions if warranted by new evidence or perspectives.


http://undsci.berkeley.edu/teaching/misconceptions.php

I know all that.
A single sentence could've said it better:

Most scientists and medical experts don't know much for sure.

Simples.

eddie wrote:I know all that.
A single sentence could've said it better:

Most scientists and medical experts don't know much for sure.

Simples.

That sounds like something Einstein would say.  Lol! You must a little scientist in you. 

It takes a true genius to be that wonderfully concise and eloquent. ;-)

eddie wrote:Ahhh. Scientists and the "experts" change their minds again....

There seem to be no such thing as "facts" anymore

NOT Science
BMI has never been a scientific index it is a health industry one.
Like Nutritionists they mislead by making it 'science sounding' but it is not science
and is notorious for 'facts' that don't even meet the minimum for (Capital T) Theory

eddie wrote:I know all that.
A single sentence could've said it better:

Most scientists and medical experts don't know much for sure.

Simples.

the other problem is media reporting, they report 'ideas that seem plausible' as facts, when really only the Scientific Laws are facts.

eddie wrote:I know all that.
A single sentence could've said it better:

Most scientists and medical experts don't know much for sure.

Simples.

Sorry sometimes you need something hammered home, when you are being antsy Eddie

@Op
I have been saying this for years as soon as i Saw the formula for measuring it.. Ridiculous it doesn't take into account muscle mass or body shape at all

Didge wrote:

eddie wrote:I know all that.
A single sentence could've said it better:

Most scientists and medical experts don't know much for sure.

Simples.

Sorry sometimes you need something hammered home, when you are being antsy Eddie

Antsy? Me?