Nutrition

As we're finished with the nutrition section, I tohught I'd post some points that we should all understand from this section.

• What is meant by a 'balanced diet', and an example of each of the seven food groups.
• Be able to define metabolism, and which process uses the majority of the energy we eat (it's  the one you don't have to think about to do).
• Understand that diferent foods have different amounts of energy per gram - if you're not sure about this one look at the previous post below this one.

With 10x2 we saw a short video about scurvy.  This is a disease caused by a lack of vitamin C, and was common in sailors who often had long voyages with no fresh food for months or years at a time. There are some good photos of the symptoms described here if you put 'scurvy' into google.

Energy in food

I found some information which relates to the practical we did earlier in the term on how much energy was in different food types.  UCLA (a uni in the U.S.) has found that the following foods contain different amounts of energy per gram:

Carbohydrate = 4 calories per gram

Protein = 4 calories per gram

Alcohol = 7 calories per gram

Fat = 9 calories per gram
The link is here if you'd like to find out more:  http://www.dining.ucla.edu/housing_site/dining/SNAC_pdf/CaloriesCount.pdf
Fats contain more energy per gram than carbohydrates do, but our bodies can digest carbohydrates more quickly than fats which is why they make up most of the energy requirements in a healthy diet.

If you're happy that different food groups have different amounts of energy per gram, and remember that we need to eat a balanced diet (enough but not too much of each food group) you should be fine for the quiz that we'll do next week.  Also knowing what each food group is needed for and what our body does with the energy it gets will be useful.

Homer Simpson

I thought I'd put the video from last lesson up to remind us about the food groups that we need to eat balanced amounts of.  It's important to realise that Homer is unhealthy as he is getting too much of some groups but not enough of others.  He could also lose weight 2 different ways:

• If he ate less, as less energy would be in excess and so stored as fat.
• If he was more active he would use more energy, again needing to store less as fat.

Metabolism and food requirements

Today we're going to start looking at what our bodies need to work efficiently and how they get these things from food.  To start with, have a read through the information on http://www.bbc.co.uk/schools/gcsebitesize/science/aqa/human/dietandexerciserev1.shtml and try the test questions at the end.
Once you've finished those, either find your own information or use the sites at the bottom to answer the following questions:

1. Define the word metabolism.
2. Explain why pregnant women usually need to eat differently to women who aren't pregnant.  Explain what issues this helps address.
3. Find out what percentage of the energy in the food you eat each day is used for growth, and what process uses the most energy.
4. Why do we need to eat food?

http://www.fao.org/docrep/007/y5686e/y5686e04.htm - Go down the page to section 2.3
http://www.sport-edge.co.uk/gi2.htm
http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/pregnancy_and_diet?open

When you've finished, try this link - http://www.purposegames.com/game/microbial-metabolism-quiz