Science & Technology in Action

2nd Edition

You Are What You Eat

Department of Agriculture, Food and the Marine

This lesson is about diet: the need for a balanced diet, the effects of having a poor diet, the part played by agriculture and how this has changed, the function of cereals and what the food pyramid is all about.
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Contains the full lesson along with a supporting toolkit, including teachers’ notes.

Lesson excerpt

“You are what you eat.” This is a frequently-quoted phase and while not strictly true it is a reminder to us to take care of our diet. In this lesson we will look at the importance and function of cereals in our diet. 

What is meant by our diet?
Our diet just means our eating habits; what, when and how much we eat. A balanced diet means good eating habits ­– eating the different types of food in a correct quantity to maintain present and future health. Our bodies are very complex chemical factories and need to be regularly supplied with food for energy and ‘building materials’ for growth, repair, reproduction and defence againstpathogens. It is also important that we maintain a suitable level of energy reserve as fat in adipose tissue.  An adult male requires approximately 15% fat reserve whereas a reproductive female requires a fat reserve of up to 25%. Either excessive or deficient fat reserves can lead to health problems.

What is a balanced diet?
A balanced diet includes the following ingredients - protein,carbohydrate, lipids (fats), vitamins and minerals. The quantity of each of the nutrients needed varies with the level of physical activity, age, sex and weight of the individual. Therefore a diet that suits one person may not suit another. A person’s dietary requirements can also vary from day to day, season to season and year to year.

How much food do we need?
Generally males need more food than females to supply their greater need for energy. Pregnant and breast-feeding females require not only a higher quantity but also a higher quality diet with special attention to particular vitamins and minerals to ensure normal development and growth of the baby.

True or False?

  1. Food supplies cells with energy for living. true
  2. Protein is stored in adipose tissue. false
  3. One diet suits all. false
  4. Agriculture began about 10,000 years ago. true
  5. Cereal crop plants evolved from wild grasses. true
  6. Rickets is not a nutritional disease. false
  7. Eating citrus fruits prevents scurvy. true
  8. Many breakfast cereals are fortified with vitamins. true
  9. Indigestible fibre is not important for health. false
  10. Antibiotic use can lead to vitamin deficiency. true
  11. Intestinal bacteria are a threat to our health. false
  12. The number of bacteria we harbour is more than the number of cells in our bodies. true