Lesson 6.2

Assessment of nutritional status 

6.2 - Body mass index (BMI)

Learning objectives

• Calculate simple nutritional indices such as body mass index (BMI) and body fat percentage.

Multiple Choice

What is Body mass index (BMI)?

• The percentage of the body that made fatty acids

• the measurement of a person's weight for their hight

Body mass index (BMI)

It is a measurement of a person’s weight for their height, used to identify weight status. 

Body mass index (BMI)

It is a measurement of a person’s weight for their height, used to identify weight status. 

How to calculate BMI

• To calculate BMI you need:

• Weight

• Height

Multiple Choice

What is the correct equation of Body Mass Index

•  $BMI=\frac{Height\ in\ m\ }{Weight\ in\ Kg}$  

•  $BMI\ =\frac{Weight\ in\ \left(Kg\ \right)}{\left(Height\ in\ m\right)^2}$  

•  $BMI=\frac{Weight\ in\ Kg}{Height\ in\ m}$  

•  $BMI=\frac{Weight\ in\ Kg}{\left(Height\ in\ cm\right)^2}$  

BMI is calculated using the following equation:

Example:

• Hind - Height:1.62 m weight: 68Kg

• Calculate BMI:

•  $BMI=\frac{Weight}{\left(Height\right)^2}$  

•  $BMI=\frac{68}{\left(1.62\right)^2}$  

•  $BMI=26$  

• BMI Classification: 

• Overweight 

Multiple Choice

Calculate Shoq BMI and identify BMI classification:

Height=1.58 m

Weight=60 Kg

• 24 - Overweight

• 24 - Underweight

• 24 - Healthy weight

• 27 - Obese

BMI activity:

Blue group https://www.liveworksheets.com/1-jg1703003gm

Pink group https://www.liveworksheets.com/1-ku1703019ie

Maroon group https://www.liveworksheets.com/1-yy1703033dl

Body fat percentage 

Sometimes it is useful to use BMI alongside body fat percentage to assess health.

 A person could be overweight or obese according to their BMI, but their body fat percentage could be quite low.

Measuring body fat percentage 

• Before you can calculate body fat percentage, you must first measure the amount of fat on the body

DEXA scanner 

• The most accurate way to measure body fat 

• The DEXA scanner is an X-ray that shows an exact breakdown of fat mass, bone density, and muscle mass.

Skinfold

• Skinfolds are areas of skin that can fold when pinched. 

• Skinfolds are measured using a tool called callipers which grip the fat through the skin at various parts of the body.

Bioelectrical impedance (BIA)

• BIA sends an electrical current through the body. The person does not feel the electrical current.

• A medical professional can tell when the electrical current is traveling through fat as opposed to muscle.

Multiple Select

Choose the methods of measuring body fat.

• Bioelectrical impedance

• Weighing scales

• Skinfold thickness

• BMI

• DEXA scanner

How to calculate body fat percentage

• 
  

• Total body weight (TBW) in kilograms (kg)

• Body fat in kilograms (kg)

• Age

body fat percentage is calculated using the following equation:

Calculate Body fat %

• Khalifa  - Body fat:28 Kg / TBW:87 Kg/ Age:38 years

•  $Body\ Fat\ \%=\frac{Body\ fat}{Total\ body\ weight}\times100$  

•  $Body\ fat\ \%=\frac{28}{87}\times100$  

•  $Body\ fat\ \%=32\%$  

• Color group: Red

Calculate Body fat %

• Mansoor  - Body fat:12 Kg / TBW:84 Kg/ Age:25 years

•  $Body\ Fat\ \%=\frac{Body\ fat}{Total\ body\ weight}\times100$  

•  $Body\ fat\ \%=\frac{12}{84}\times100$  

•  $Body\ fat\ \%=14\%$  

• Color group: Green

Calculate Body fat %

• Mouza  - Body fat:18 Kg / TBW:75 Kg/ Age:58 years

•  $Body\ Fat\ \%=\frac{Body\ fat}{Total\ body\ weight}\times100$  

•  $Body\ fat\ \%=\frac{18}{75}\times100$  

•  $Body\ fat\ \%=24\%$  

• Color group: Green

Calculate Body fat %

• Amal  - Body fat:29 Kg / TBW:72 Kg/ Age:67 years

•  $Body\ Fat\ \%=\frac{Body\ fat}{Total\ body\ weight}\times100$  

•  $Body\ fat\ \%=\frac{29}{72}\times100$  

•  $Body\ fat\ \%=40\%$  

• Color group: Amber

Poll

How are you feeling about this lesson?

• Great! Easy stuff.

• Yikes. I kind of know what's going on, but not really.

• Yikes. I kind of know what's going on, but not really.

• Wait, I'm taking Health Sciences?!