Noadswood Science, 2012

BER & BMI To understand the terms BER and BMI

Wednesday, April 19, 2023

Energy Where do we get our energy from, and what do we use it

for?

Our energy is derived from food - whereas plants can produce their own energy from sunlight, we must consume food

This food is our raw material - needed to make new substances for: - Energy (movement etc…) Growth and repair Health

Balanced A balanced diet contains the different nutrients in the correct

amounts, keeping us healthy

Certain foods are not necessarily 'bad' for us, but eating too much of them could be

Foods contain nutrients: these are substances which provide raw materials for the body (we need nutrients, along with fibre and water for a healthy diet)

There are seven different nutrients, and some foods are particular rich in certain nutrients…

Essential Nutrients are found within different foods, and they all play

important roles within the body

Nutrient How the body uses it Food sources it is contained in

Carbohydrate To provide energyCereals; bread; pasta; potatoes (sugars

and starch)

ProteinFor growth, making new cells and repair

of our bodiesFish; meat; eggs; dairy products

FatTo provide energy, as a store of energy

& for insulationButter; oil; nuts

MineralsNeeded in small amounts to maintain

healthSalt; milk (calcium); liver (iron)

VitaminsNeeded in small amounts to maintain

healthDairy foods; fruit; vegetables

FibreTo provide roughage to help keep food

passing through the gutVegetables; bran; wholemeal bread

Water Needed by cells and for body fluids Fruit juice; milk; water(!)

Food Complete the food

worksheet…

Food

Right Amount Of Food – Too Little

If you don't eat enough food, you will become too thin and may suffer from health problems…

These problems can include: - Irregular periods in women Reduced resistance to infection Deficiency diseases

Right Amount Of Food – Too Little

Deficiency diseases include rickets and kwashiorkor

Rickets affects proper growth of the skeleton and is caused by insufficient vitamin D

Kwashiorkor causes a swollen abdomen and is a result of insufficient protein

Problems such as these are more likely to affect people in the developing world, where it can be more difficult to get enough food

Right Amount Of Food – Too Much

In warm weather, or when you don't do much exercise, you do not need to eat as much food as when it is cold or when you have exerted yourself physically

If you eat too much food without taking enough exercise, you will become overweight

Very fat people are described as obese

Right Amount Of Food – Too Much

Overweight people may suffer from health problems, including: - Diabetes (type 2) - an illness in which the body is unable

to control the amount of sugar in the blood Arthritis - an illness in which the joints become worn,

inflamed and painful High blood pressure Heart disease

BMI BMI (body mass index) is a scale to determine your ideal

weight

The calculation is your weight (kg) ÷ height2 (m)

BMI BMI is not always right! Look at the two people below – why

might there BMI tell them they are unhealthy?!

Body builder - very high BMI (although this is overwhelmingly muscle, not fat)

Elite marathon runner – very low BMI (very healthy diet, just so many calories constantly

burnt running (~1000 per hour))

Body Fat The average person has between 17 and 25% body fat

A large proportion of the population may be well over 30%

An oarsman at the peak of his game will probably be between 8 and 12%

Body Fat To calculate body fat use the callipers and pinch your skin-

fold at various points (take an average in mm)

Identify your weight (kg), height (m), age and gender

Body fat %...

Body Fat – Men (All Locations)

Skin-fold(mm)

Age

16-29 30-39 40-49 50+

16182022

6.77.98.19.2

9.310.812.013.0

9.510.912.213.5

9.711.012.513.9

24262830

10.211.212.112.9

13.914.715.516.2

14.615.716.717.6

15.116.317.418.5

35404550

14.716.317.719.0

17.819.220.421.5

19.721.523.124.6

20.822.824.726.3

55606570

20.221.222.223.2

22.523.524.323.2

25.927.128.229.3

27.829.130.431.5

75808590

24.024.825.626.3

25.926.627.628.3

30.231.232.132.9

32.633.734.635.5

95100110120

27.027.628.829.9

29.029.730.932.0

33.834.535.837.1

36.537.338.840.2

130140150160

31.031.932.833.6

33.034.034.835.7

38.239.440.441.4

41.542.843.945.0

170180190200

34.435.235.936.5

36.537.237.938.6

42.343.143.944.7

46.047.047.948.8

Body Fat – Women (All Locations)

Skin-fold(mm)

Age

16-29 30-39 40-49 50+

14161820

9.411.212.714.1

12.714.315.717.0

15.617.218.519.8

17.018.620.121.4

22242628

15.416.517.618.6

18.119.220.121.1

20.922.022.923.8

22.623.724.825.7

30354045

19.521.623.425.0

21.923.825.527.0

24.627.228.129.6

26.628.630.331.9

50556065

26.527.829.130.2

28.329.530.631.6

30.932.133.234.2

33.234.635.736.7

70758085

31.232.233.134.0

32.633.534.335.2

35.136.736.838.4

37.738.639.540.4

9095

100110

34.835.636.337.7

36.036.738.438.7

39.139.940.641.8

41.141.942.643.9

120130140150

39.040.241.342.3

39.941.142.143.1

43.044.145.146.0

45.146.247.348.2

160170180190

43.244.645.045.8

44.045.145.646.4

46.947.848.549.3

49.150.050.851.6

Basic Energy Requirements Basic Energy Requirements (BER) is based on how much

you weigh, and gives an indication of how much energy you need per hour (though this will be dependent on your lifestyle (e.g. your age / if you’re active / pregnant etc…))

For every kilogram of your weight you need 5.4kJ to keep you alive

BER (kJ) = Weight (kg) x 5.4

E.g. 80kg man would have a BER of 432kJ per hour

BER of 10’368kJ per day (or 2476 calories)

* 1kJ = 0.24 calories

Food Diary Daily energy requirements of an individual depend on their

mass (weight) and that this requirement also increases during exercise

Diet diaries are used by athletes to recall their food intake (a basic one is over a period of 24 hours, however the longer it is taken the more accurate it becomes) – they can then compare this to their exercise routine (and how many calories each activity is using) and this will make their specific BER more accurate…

Using the worksheet complete your own food diary (write the type of food and portion size (and ideally the calorie intake)) over a 24 hour period, and note time the energy you used depending upon the type of exercise you did in that time

Food Diary