BMI – an effective tool or a relic?

BMI – an effective tool or a relic?

Body Mass Index, also known as the Queteleta II Indicator, is a body mass factor used by specialists to define customer’s parameters and to classify patients on the BMI table.

How to calculate BMI?

Just have a look at the formula below based on two of the most commonly used unit systems:

• BMI = weight(kg)/height2(m2)         (Metric Units)
• BMI = 703·weight(lb)/height2(in2)         (U.S. Units)

This formula is used mainly for adults.

In order to evaluate children’s and young adult’s Body Mass Index, specialist created special growth charts that reflect development for specific age and population.

BMI is a tool which is very easy to use. That might be the reason of its popularity and why it’s used so commonly by nutritions and dietitians in order to evaluate the body weight.

Increased BMI factor might lead to a large number of various medical conditions like cardiovascular disease, type II diabetes, overweight or obesity. It is very important to get the BMI factor right in order to prevent these medical conditions to occur.

BMI calculator

BMI classification

•    < 16,0 – severe thinnes
• 16,0–16,99 – moderate thinnes
• 17,0–18,49 – mild thinnes
• 18,5–24,99 – normal range
• 25,0–29,99 – overweight
• 30,0–34,99 – obese class I
• 35,0–39,99 – obese class II
•       ≥ 40,0  – obese class III

The BMI factor is based on an average population which, as a result, might be imperfect when it comes to certain individuals.That’s the reason why everyone should remember about the margin for error in some cases.

Why is that so? The main reason is BMI factor doesn’t take fat, bone or muscle tissue under consideration. It means that BMI results for a very muscular person with a large muscle tissue content will be above average which will classify him as someone who is overweight.

It works the other way too. For example an elder person that has higher level of fat tissue than someone who is younger than them might be mistakenly classified as someone with a normal BMI range. Not taking action might lead to a serious medical condition with catastrophic results.

BMI factor

What is the conclusion then? The most obvious one is that BMI factor is the right tool to classify body mass for whole populations, but not individuals.

Dietitians and nutritionist started using new innovative factors like WHR factor that evaluates internal fatness or BIA.

Did you know that TiqDiet program can integrate with body composition analysers?

• You can type data like:
• body weight,
• height,
• waist size,
• thighs size,
• BMI,
• TBF,
• TBW,
• TBM.

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2. Bogusława Baranowska, Barbara Krzyżanowska-Świniarska: Zaburzenia odżywiania. W: Piotr Gajewski, Andrzej Budaj, Wiktoria Leśniak, Ewa Niżankowska-Mogilnicka, Filip Mejza, Witold Bartnik, Łukasz Streszyński, Barbara Jarząb, Ewa Płaczkiewicz-Jankowska, Franciszek Kokot, Robert Drabczyk, Andrzej Hellman, Bogdan Ochrem, Irena Zimmermann-Górska, Jan Sznajd, Marek L. Kowalski, Agnieszka, Padjas, Anna Członkowska, Marek Bodzioch, Maciej Krzakowski, Krzysztof Krzemieniecki, Wojciech Wysocki, Piotr Zaborowski, Janusz Szajewski, Konstanty Szułdrzyński, Jacek Łuczak, Roman Jaschke, Miłosz Jankowski, Bogdan Solnica, Jacek Mrukowicz, Grzegorz Goncerz & Bartłomiej Rogorz: Interna Szczeklika. Podręcznik chorób wewnętrznych 2013. Kraków: Medycyna Praktyczna, 2013, s. 1402
3. WHO :: Global Database on Body Mass Index