TOPIC 2 - NUTRITIONUnderstand percentage body fat/body composition and body max index (BMI) as ways of measuring whether a persons diet is nutritionally healthy for themUnderstand definition of obesity and the limitations to defining it

Learning Outcomes:

A – Attempt exam questions using notes to Support answers

B – Define Obesity and Explain what and why there are limitations

C – Define and Understand the terms of BMR, BMI and Percentage Body Fat

Do Now Task – Attempt the questions on the hand out

ENERGY

Humans like all living beings need to get energy from somewhere.We use the chemical energy that we can extract from food.

We oxidise food to produce energy, carbon dioxide and water.

Food Energy, CO2, Water

The actual amount of energy we need will vary from person to person and is dependant on their Basel Metabolic Rate and how

much activity they do

oxidation

BMR – BASEL METABOLIC RATE

How quickly the body uses up energy to complete the basic bodily functions. Therefore it is different for every body.

Infants and young people have high BMR’s in relation to their size due to how quick they grow and develop. Men have a higher BMR due to more muscle.

BMR is ¾ of your energy needs.

Level of activity and body weight are all factors of the amount of energy a person requires. High levels of activity allow a person to consume more energy

without gaining weight

PERCENTAGE BODY FAT

Body weight is a good guide into a person energy balance. Balanced energy is delivered though equal energy input (food) to output (activity).

Any excess intake of energy above what is needed daily is stored in the body as fat.

Body mass is made up of 2 things. Lean body mass (muscles, bones and organs) and body fat.

Average men 10-20% body fat, women 15-25% body fat. A person who is very fat will have a percentage body fat higher than these norms

Percentage Body fat can be measured in a number of ways.Skin Fold Test – Measure specific sections of skin around the body.

This is then compared to relative norm tables.Problems with this?

Dependant on the accuracy of the person measuringBioelectrical Impedance Method – A device has your age, gender, height and weight put

into it. Then electricity is passed though you from one electrode to the other and a reading is calculated

Most effective way is to be submerged in water and measure how much water is lost

PERCENTAGE BODY FAT CONT.

OBESITY – A PERSONS BODY FAT PERCENTAGE IS HIGHER THAN 40%

A condition where excess fat accumulation can impair health. A BMI of over 30 is also deemed obese as well the percentage body

fat limit of 40%.It is a symptom not a measurable quantity so it becomes difficult to

define.If energy intake is higher that output regularly, weight will be

gained leading to obesity.

BMI – BODY MASS INDEX

This is used to judge whether a person is the correct weight for their height.Weight/height (squared) = BMI

Kg/M2 = BMIThere is a strong relationship between BMI and the risk of associated diseases

What are some of the issues with this?

INDEPENDENT TASK

Use page 18-20 do design a pamphlet that warns being people of the risks of becoming over weight and obese.

It has to include the following keywords/information

• Obesity related diseases• Reasons for weight loss/gain

• Activity Levels• Issues with being overweight

• Prevention of obesity• Moderate activity

• Intensity• Obese

• BMI• BMR

• Statistics on obesity• Activity Levels adults/children

QUESTIONS

Attempt your Do Now questions again.