Energy Requirements and Macronutrient Ratios

Fuelling the body

The body needs energy from food, and that energy is measured in kilocalories, written kcal. An average adult male needs about 2500 kcal a day and an average adult female about 2000 kcal, though this varies with age, height and how active a person is. A balanced diet supplies this energy from three macronutrients in set proportions: mostly carbohydrate, then fat, then protein. This module covers the energy figures, the balance of a healthy diet, and the job each macronutrient does for a performer.

Nutrition words

Learn these four words before you sort any nutrient, and memorise the kcal figures and diet ratios exactly, because precise numbers are among the easiest marks to earn on this topic. Each term below describes part of how the body is fuelled and kept working.

Three macronutrients, three jobs

A balanced diet is mostly carbohydrate, with less fat and least protein. Each has a different job for a performer.

How to match need to nutrient

Start from what the body needs. For quick, hard effort at any intensity, reach for the main fuel. For long, gentle effort, the body can also draw on its store of the low-intensity fuel. To build and mend muscle after training, the body needs the repair nutrient. Learn the daily energy figures and the diet balance exactly, because precise numbers earn marks. Then match each need to the nutrient that meets it.

Match the nutrient to its job

What is the main energy source?

Which macronutrient is the main and preferred source of energy at all intensities?

• Carbohydrate.
• Fat.
• Protein.
• Water.

A balanced diet

Select the TWO statements that are true of a balanced diet.

• Carbohydrate makes up the largest share
• Protein makes up the smallest share of the three
• Protein makes up more than half the diet
• A healthy diet contains no fat at all

Work out the energy gap

An average adult male needs about 2500 kcal a day and an average adult female about 2000 kcal a day. Subtract to find how many more kcal the average male needs than the average female. What is the answer?

Order the diet shares

Put the three macronutrients in order of their share of a balanced diet, largest share first.

• Carbohydrate, about 55 to 60 per cent
• Fat, about 25 to 30 per cent
• Protein, about 15 to 20 per cent
• Vitamins and minerals, needed only in tiny amounts

Complete the facts

The largest share of a balanced diet, and the main energy source at all intensities, is _____. An energy source used efficiently only at low intensity is _____. The nutrient used for growth and repair is _____. A diet with the right mix of all of these in the right proportions is a _____ diet.

Match the need to the nutrient

Spot the true nutrition facts

Tap the TWO statements that are true about energy and macronutrients.

• Carbohydrate is the main energy source at all intensities
• Protein is used for growth and repair
• Fat is the best fuel for high-intensity sprints
• Protein should make up most of a balanced diet

Choose the nutrient

Read each case and choose the nutrient that best meets the need.

• A footballer needs a reliable fuel for a full match of running at many different intensities. Which nutrient should be the main source?
• A weightlifter has torn muscle fibres in training and needs to repair and build them. Which nutrient is most important now?
• A student claims a healthy diet should be mostly protein with very little carbohydrate. Is this correct?

Explain energy and diet

Explain how much energy an adult needs, what a balanced diet is made of, and the job each macronutrient does for a performer.

• State the rough daily kcal needs of an average adult male and female
• State the balance of carbohydrate, fat and protein in a healthy diet
• Explain the role of carbohydrate and when it is used
• Explain the roles of fat and of protein