6 common myths about body mass index

Thanks to the body mass index (BMI), you can find out how a person’s weight and height cor­re­late: the num­ber indi­cat­ing weight (kg) is divid­ed by the num­ber indi­cat­ing height (m), squared. This indi­ca­tor is main­ly used to deter­mine whether a per­son­’s weight exceeds the norm. Despite com­mon mis­con­cep­tions, BMI is not able to accu­rate­ly indi­cate the amount of fat deposits in the body or the pos­si­ble dis­eases of a per­son. What oth­er myths about BMI are use­ful to know?

Body mass index and health

This index is rel­e­vant to cal­cu­late for adults of both sex­es aged 20 years and old­er. For chil­dren aged 2 years and old­er, this indi­ca­tor is esti­mat­ed as a per­cent­age. That is, the results of a par­tic­u­lar child are com­pared with the aver­age result of oth­er chil­dren of the same age and gen­der. To cal­cu­late BMI, you do not need to use any equip­ment, per­form com­plex exer­cis­es or vis­it a doc­tor. It is enough to resort to the help of online cal­cu­la­tors, which are easy to find on var­i­ous sites. All you need to do is enter your height and weight data and the result will be cal­cu­lat­ed auto­mat­i­cal­ly.

If the BMI is too high, then this means that the per­son­’s weight is out­side the nor­mal range. But this does not always mean that the body has accu­mu­lat­ed a lot of fat. BMI is con­sid­ered a sim­ple and easy-to-use method for assess­ing the state of fat mass and body weight. But he is not per­fect. For exam­ple, in ath­letes, an increase in their mus­cle mass can be mis­tak­en for the accu­mu­la­tion of fat. The index may not take into account the amount of body fat in old­er peo­ple and those cas­es when the body los­es mus­cle mass. There­fore, BMI data can­not be tak­en lit­er­al­ly. Here are some com­mon myths asso­ci­at­ed with this indi­ca­tor.

Myth #1: Regular exercise guarantees a healthy BMI.

Prop­er diet and reg­u­lar exer­cise are key fac­tors in keep­ing the body in good shape. How­ev­er, this does not always lead to a nor­mal BMI, since this indi­ca­tor does not dis­tin­guish between fat and mus­cle. It must be borne in mind that mus­cles are a pri­ori heav­ier than fat, so a per­son who reg­u­lar­ly exer­cis­es and eats healthy food can have a lean body and a high BMI. That is why with a cer­tain diet and reg­u­lar exer­cise, a per­son grad­u­al­ly begins to gain mus­cle mass and weigh more. An over­es­ti­mat­ed BMI also hap­pens with health prob­lems, indi­cat­ing the onset of the dis­ease. On the oth­er hand, even a very mas­sive per­son can be absolute­ly healthy.

Myth #2: A lower BMI is indicative of good health.

Excess fat is asso­ci­at­ed with high lev­els of sug­ar and cho­les­terol in the blood. How­ev­er, a BMI below nor­mal does not guar­an­tee a per­son the absence of dis­ease and health prob­lems. Peo­ple with a low BMI are at a high­er risk of devel­op­ing infec­tions than peo­ple who are over­weight. The rea­son is that an under­weight body is more prone to immune sys­tem dis­or­ders.

Accord­ing to stud­ies con­duct­ed in Korea, men and women with low BMI are more like­ly to suf­fer from res­pi­ra­to­ry dis­eases that affect the res­pi­ra­to­ry sys­tem. More­over, the risk of death in res­pi­ra­to­ry dis­eases is high­er in patients with low BMI.

It is impor­tant to con­sid­er that an out­ward­ly thin body is capa­ble of accu­mu­lat­ing harm­ful fat in itself, which col­lects near the inter­nal organs. At the same time, peo­ple with vis­cer­al fat are at a high­er risk of heart dis­ease, type 2 dia­betes and can­cer. There­fore, do not think that you can stay healthy just because the BMI is not high.

Myth #3: BMI can determine the onset of disease

BMI is not peremp­to­ry and the same indi­ca­tor for all peo­ple, espe­cial­ly for tall and ath­let­ic peo­ple. Obe­si­ty experts have report­ed after research that about 74.9 mil­lion adults have been mis­di­ag­nosed with heart dis­ease based on BMI alone. There­fore, doc­tors should not get hung up on only one indi­ca­tor of BMI, since this can miss the true cause of poor health. Going for a med­ical exam­i­na­tion, it is desir­able to under­go a com­plete exam­i­na­tion of the body.

Myth #4: The BMI formula is effective in assessing the health and obesity of both individuals and entire populations.

Con­trary to pop­u­lar belief, BMI is not suit­able for an accu­rate assess­ment of the state of obe­si­ty and the health of an indi­vid­ual. But it can be an effec­tive tool for rough­ly esti­mat­ing obe­si­ty and over­weight at the pop­u­la­tion lev­el. The BMI for­mu­la was orig­i­nal­ly cre­at­ed by a math­e­mati­cian, not a doc­tor. With this sim­pli­fied indi­ca­tor of the ratio of weight to height, body con­sti­tu­tion and age are not tak­en into account. There­fore, this indi­ca­tor can­not be inter­pret­ed as pre­dict­ing obe­si­ty and health sta­tus for each indi­vid­ual.

Myth #5: A high BMI increases the risk of developing cardiovascular disease.

Indeed, a per­son with a high BMI is at greater risk of a heart attack. But such a state­ment can­not be called the final truth. The con­tro­ver­sy of this sit­u­a­tion was proved by British stud­ies in which 4,046 pairs of iden­ti­cal twins par­tic­i­pat­ed. Each cou­ple had the same DNA but dif­fer­ent lev­els of body fat. Sci­en­tists say that not every broth­er or sis­ter of an iden­ti­cal cou­ple with a large BMI had a high risk of heart fail­ure. A high­er BMI may be asso­ci­at­ed with an increased risk of type 2 dia­betes, the study found.

In par­al­lel, South Asians with a high BMI were found to have no increased risk of death from heart dis­ease. How­ev­er, sci­en­tists say that if BMI is nor­mal, then this indi­ca­tor does not reduce the risk of devel­op­ing car­diometa­bol­ic prob­lems.

Myth #6: A normal BMI is an indicator of normal body condition.

If an adult has a BMI in the range of 18.5 to 24.9, this is a sure sign that the weight is with­in the nor­mal range. But this does not mean that the per­son is healthy. In addi­tion, if a per­son is thin, this does not mean that his health is bet­ter than that of an over­weight per­son. Health sta­tus depends on many fac­tors, includ­ing hered­i­ty, gen­der, lifestyle, nutri­tion, and more.

If a per­son with a nor­mal BMI smokes a lot or abus­es alco­hol, it is dif­fi­cult to con­sid­er his body healthy. Peo­ple who smoke and drink are more at risk of wors­en­ing over­all well-being. There­fore, you should not take a nor­mal BMI as an indi­ca­tor of good health.