200 likes | 398 Views
Noadswood Science, 2012. BER & BMI. BER & BMI. To understand the terms BER and BMI. 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
E N D
Noadswood Science, 2012 BER & BMI
BER & BMI • To understand the terms BER and BMI
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
Food • Complete the food worksheet…
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 %...
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