Principles of Nutrition

What food does inside you

Food is not just fuel. Every meal is a mixture of nutrients, and each nutrient does a particular job once it is inside the body. The nutrients split into two groups. The macronutrients, needed in large amounts, are protein for growth and repair, and carbohydrate and fat for energy. The micronutrients, needed in small amounts but still vital, are the vitamins and minerals, such as vitamin C, calcium and iron, each with its own job. On top of those the body needs water and fibre to keep working. A balanced diet is simply getting the right amount of each of these. This module teaches what each nutrient does, which foods provide it, and what can happen when the body does not get enough, so that you can look at any meal and say what it gives and what it lacks.

Words for nutrients

Learn what each of these means before you use it.

Macronutrients against micronutrients

Nutrients divide into two groups by how much of them the body needs, though both matter.

How to answer a nutrition question

A nutrition question is answered the same way almost every time, so learn the routine. First, name the exact nutrient the question is about, not just food in general. Second, state its main job in the body in one clear phrase. Third, give a food that provides it, and if the question asks, say what too little of it can lead to. A weak answer says a food is healthy. A strong answer names the nutrient, says what it does, and gives a source. Name the nutrient, state its job, give a source. That habit turns a vague comment into a mark.

Match the nutrient to its job

Which nutrient?

A teenager is growing quickly and needs plenty of the nutrient the body uses to build new tissue and repair itself. Which nutrient is most important for that?

• protein
• carbohydrate
• fat
• fibre

Order the balanced-meal check

Put the steps for checking whether a meal is balanced in a sensible order.

• List the foods that make up the meal
• Work out which nutrients those foods provide
• Check whether the main nutrient groups are all present
• Adjust the meal to fill any nutrient that is missing

Spot the true nutrition facts

Tap the TWO statements that are true.

• Protein is needed for growth and the repair of the body
• Iron helps make red blood cells, and too little can cause tiredness
• Carbohydrate gives the body no energy at all
• Micronutrients are needed in very large amounts every day

How many macronutrients left?

There are 3 macronutrients: protein, carbohydrate and fat. So far you have studied 1 of them closely. Subtract to find how many of the 3 are left to study.

Complete the nutrition facts

The nutrient used for growth and repair is _____. The main source of energy for the body is _____. The mineral that builds strong bones and teeth is _____. The mineral that helps make red blood cells and whose lack can cause tiredness is _____.

Reading a plate

Picture a plate holding grilled chicken, a scoop of rice, some steamed broccoli and a glass of milk. Instead of asking whether it looks healthy, read it nutrient by nutrient. The chicken is there for growth and repair. The rice is the energy on the plate, the fuel that keeps the person going. The broccoli brings vitamins and some fibre, the small-amount nutrients and the roughage that keeps digestion moving. The milk adds the mineral that hardens bones and teeth. Now spot the gap: there is little here that is high in the mineral needed for red blood cells, so a portion of leafy greens or a different meat later in the day would round it out. That is what reading a plate looks like: name what each part provides, then name what is thin, all without guessing a single number.

Build the nutrient rule

Choose the words that complete the rule for writing about a nutrient.

Meet the need

Read each case and choose the best answer, then think about why.

• Someone often feels tired and a nurse suspects their diet is low in one mineral that helps carry oxygen in the blood. Which nutrient should they eat more of?
• A meal has plenty of energy foods but almost nothing for growth and repair. What is the best fix?
• You must explain why a diet needs calcium as well as protein. What is the clearest point?

Nutrients and the body

Select the TWO statements that are true.

• Calcium helps build strong bones and teeth
• Dietary fibre helps keep the digestive system working
• Protein exists only to give the body quick energy
• The body can work perfectly well with no water

Explain nutrition

A friend is revising Food Preparation and Nutrition and thinks a food is either just healthy or unhealthy. Explain how nutrients really work, using the ideas from this module.

• Explain the difference between macronutrients and micronutrients
• Explain the job of protein and the job of carbohydrate
• Explain what two named vitamins or minerals do, such as calcium and iron
• Explain why water and fibre are also needed
• Finish by explaining what a balanced diet means and how to spot what a meal is missing