“…the leaner we are, the healthier we are. And of course, the more physically fit [we are], the better off we are when it comes to over all health.”
Dr David Lau,University of Calgary
A couple of days ago,to be specific on Tuesday I posted an article from the Independent on How Clean eating was having an effect on young women and had gone on to demonize certain food groups,you may want to read it,please do.
Thereafter followed a vibrant conversation from the people who read it and rearing its head very often were these 3 letters -BMI.
BMI or Body Mass Index as we know it has been bandied around by health and medical professionals and we have scared people into thinking that it is the be all,end all and ultimate marker of good health.What scientist have found is that BMI scores vary among different groups and some like countries in South Asia have developed their own way of calculating BMI’s among their populations.
At its inception , the BMI was a simple,easy tool to screen populations at a time when Western populations were having to come to terms with the increase in obesity in their populations that were becoming more prosperous and were seeing changes in dietary habits.
Health and medical professionals now use the BMI to determine “how much body fat ” you are carrying .Research however shows that the amount of body fat individuals carry varies across ethnic groups.
For most people in Kenya ,finding their BMI score is a scary thing , especially when they find out that they score a higher or lower than average score and fall on either of two extremes, severely underweight or morbidly obese.
As a guide a Body Mass Index was developed thanks to a population of individuals who were all of European descent.Any casual observer can l see that as Africans our physiology is different from Europeans and since the BMI does not differentiate between body fat and muscles we will have different scores among different ethnic groups .
But what is the Body Mass Index really and how did it come about and is it really a good indicator of how healthy you are or of how much weight you should gain or lose?
To better understand what the Body Mass Index is,we have to go back in history ,more than 150 years ago to the 1830’s through to the 1850’S when the BMI was first developed by the Belgian Lambert Adolphe Jacques Quetelet.
As a tool for studying population trends and giving a rough idea of the health status of groups to medical professionals it proved very useful .What it was not able to point out was the amount of visceral fat individuals carried with them.
Visceral fat you said…this is the fat that is around your abdomen and internal organs and is the dangerous kind of fat that will predispose you to conditions like diabetes Type 2,hypertension and other cardiovascular diseases.
The amount of visceral fat we carry is more worrying than the BMI score .
When you first get your BMI,remember it is the value got from the weight of an individual divided by their height squared and will give you kg/m squared.
The resulting value is used to classify individuals as underweight,normal weight,overweight or obese.As such when describing an individual’s BMI score,one often hears the description of the resulting value being how far from the ideal one’s weight is from what is desirable for their height.
Over the years there has been an increase in the concern of using a universal cut off point to determine the health of individuals and scientists have been calling for a more individualized approach to determine the health of individuals as Body Mass Index has been shown to differ among ethnic groups .
In a paper titled Ethnicity and BMI ,that was published in the British Journal of Nutrition by Amy Luke a Professor from the University of Loyola’S Department of Preventive Medicine and Epidemiology,she wrote:
“The WHO’s 2004 call for more research to be conducted in diverse populations seems quite important and necessary if the relationships between BMI,body fat and chronic disease are to be better defined.”
Individuals who are more athletic and have more muscle than fat may also inadvertently find themselves in the overweight bracket and shorter people find themselves being classified as thinner than they really are.
As a result with the BMI , it does not differentiate between body fat and muscle and people will sometimes find themselves in the wrong classification. Some scientists have argued that using a waist to height ratio would give a better and more specific evaluation of a person’s health .
Why a waist to height ratio ?
Because a waist to height ratio is a better indicator of abdominal fat and abdominal fat has been shown to be a better predictor of individuals predisposed to obesity related health conditions.
However,the jury is still out on this and the BMI remains king. .
To be clear, the Body Mass Index is a good tool for population studies but not for individualized health care.The World Health Organization has defined obesity as a condition in which excess body fat affects the health and well-being of an individual and it has used the Body Mass Index as a tool to classify individuals ,research however has shown that Body Mass Index across ethnic ,cultural groups differs and genetics and environmental factors also affect our well being.
When the BMI was developed humans were leaner and having mainly focused on Western societies where diets were different from lets say individuals in Africa and Asian countries,the Index was and is a guide and could be used with other more specific tests to determine the health of individuals .
In this paper published in the scientific journal PLOS ONE ,scientist from Leeds Beckett University do say that Body Mass Index while remaining a useful tool for population screening is not able to identify individuals at risk of developing obesity related medical conditions.
Do we then get rid of the BMI and stop using it as a guide to screen individuals at risk of health complications ?
No,we should not, instead of chasing a number that determines how perfectly healthy we are,it will be more useful to adopt a healthier lifestyle by making healthier food choices and adopting more active lifestyles .
Active lifestyles where we incorporate more exercise will ensure we burn more of the visceral fat we carry,making healthier food choices like cutting back on alcohol,cutting back on deep fried foods,eating more fiber rich foods are ways of ensuring that you can lose the abdominal fat you carry with you and reduce you waist to height body fat ratio.
My challenge to the great scientists and researchers in Africa would be for us to adopt more multi pronged approaches to tackle the heath challenges of the continents population .Countries in South Asia have been able to do so.
We could do more research on the increasing number of lifestyle conditions that are on the rise on the continent and share ideas of how we can help our populations adopt more healthy lifestyles.We should promote consumption of more indigenous foods,advocate for more active lifestyles and create policies that will advance healthier lifestyles.
For now do not just rely on your BMI,take a more active step towards living healthier by making more healthy food choices and becoming more active.