UNIT 2 – BIOLOGICAL WORLD


The food pyramid The food pyramid can be used to help people plan a balanced diet.


To get the correct quantity of biomolecules, vitamins and minerals in their diet, a person should eat the most servings of the food from the bottom of the pyramid and only small amounts of the food from the top of the pyramid.


:Fig. 10.8 The food pyramid ? TEST TUBE


6. Look at the food pyramid shown in Fig. 10.8. a. Name two types of food that should be eaten in small amounts only. b. Explain why these foods should be eaten in small amounts.


7. One of the criticisms of the food pyramid is that it does not consider portion size. Explain why this is an issue.


Factors affecting diet


The food pyramid provides a general guide to a balanced diet, but the following factors must also be considered in relation to the amount of food a person should eat:


• Age: young people that are still growing need more food than adults


• Sex: males generally need more food than females • Genetics: people who are physically larger need more food • Health: people who are ill may lose their appetite


• Physical activity: people who have active lifestyles need more food than people who are less active


These factors affect how much a person eats because the food a person eats must supply the energy their body needs to carry out functions.


98 Elements of Science


:Fig. 10.9 We need to eat more food and drink more water when we exercise


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