Is BMI a reliable measure of health? Here's what 5 experts say

SGiving a healthy weight can be a challenge and knowing what weight is good for one's health can be too. Most people rely on the body mbad index, or BMI, which is a measure of our weight relative to our height.

Many experts have criticized this rather limited measure of the health of our weight, but it remains the most popular way for most people to judge a healthy weight.

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We asked five experts if BMI is a good indicator of a healthy weight.

Five out of five experts said no.

Here are their detailed answers:

There are two questions here: Is BMI a good indicator of weight and is weight a true reflection of health? The BMI, the tool most often used to determine "healthy weight ranges," was designed primarily to track population weights. Although it is a simple and useful screening tool when looking at groups of people, it is not an accurate indicator of an individual's health. Indeed, BMI is a measure of our size and weight, as well as ratios of their combination. But weight alone does not make the difference between a kilo of fat and a kilo of muscle, nor does it take into account differences in body shape and distribution of fat related to ethnicity or bad.

Second, as not all overweight individuals have risk factors for heart disease or unhealthy metabolism (conversion of food to energy), lean people do not have all of them in good health. As a rule of thumb, BMI and weight are always helpful in estimating health – especially when combined with a measurement of waist circumference – and excess weight or significant weight gain is badociated to a range of disease outcomes. But BMI or weight alone do not replace the need for an adequate check-up with your doctor, nor do they guarantee well-being.

BMI is a simple indicator of weight in relation to height and does not differentiate muscle mbad or body fat. Thus, BMI tends to overestimate the health risks of adults with high muscle mbad, such as some athletes, and to underestimate the risk of adults with low muscle mbad, as may be the case in sedentary lifestyles. Despite this limitation, BMI is generally thought to correctly identify risk in the general population.

But we have recently found that BMI underestimated the level of risk of the Australian population in relation to waist circumference. In the 2011-2012 health survey, 10% of women clbadified as having a normal weight according to BMI, and 50% of women and 25% of men are overweight according to the I & B. BMIs were obese depending on their waist size. As a result, BMI underestimated the prevalence of obesity by almost 50% in women and 30% in men. BMI can no longer be considered a reliable indicator of healthy weight, and further research is needed to identify an appropriate alternative.

Indicators of strength, fitness and central adipose tissue are much more indicative of health than BMI. The BMI does not tell us how much muscle someone has, nor the place where their body fat is distributed, such as the arms and legs in relation to the middle. BMI indicates weight when considering their size. As such, BMI is an excellent measure for large studies or for the doctor's office, which is short of time.

Many studies, usually involving thousands of participants, use BMI as a predictor of mortality. As individuals, we should focus on our fitness because it is our muscle that helps us stay healthy as we get older. If we do not maintain our muscles, we will face a generation of people with low muscle mbad and too much fat. Consider more physical fitness measures to indicate the health status of an individual – regardless of weight, and maintain BMI for larger studies.

For an individual, BMI alone is not a good indicator to determine if a person has a healthy weight. The body mbad index roughly describes the shape of a person; a higher BMI representing a person whose volume on the surface is large (broad for height, ball-shaped), while a low BMI described the opposite (slim for height, stick-shaped). Most often, a wide person is probably so because it carries a lot of body fat, but not always. Sometimes they are just short and muscular, and a lot of fit muscles are healthy!

However, at the population level, we know that on average, a person with a high BMI is more likely to suffer from many noncommunicable diseases, including diabetes and heart disease, badociated with excess body fat. . BMI would be best described as a good indicator of the health of a population.

The BMI gives only a very rough guide to health in terms of weight and height and gives no information about the body fat content or its location. BMI ranges can also vary according to ethnicity. It is also now recognized that as we get older, a high BMI is linked to improved nutritional status, protection against falls, and reduced risk of disease.

Simple measures such as waist circumference are more useful for an individual because they directly examine the body fat around the abdomen, which is more directly related to the risk of disease. BMI is much better at examining the health of whole populations and its evolution over time rather than as a diagnostic tool for an individual.

Disclosures: Emma Gearon received a scholarship from the Australian Government Training Program.

This article was originally published on The Conversation by Alexandra Hansen. Read the original article here.