What makes a balanced diet, and how does nutrition support performance?
The components of a balanced diet, the role of macronutrients and micronutrients, carbohydrate loading and protein timing, and the calculation of BMI.
A focused answer to Edexcel GCSE PE on diet and nutrition: a balanced diet, the role of carbohydrates, proteins, fats, vitamins, minerals, water and fibre, carbohydrate loading and protein timing, and how to calculate and interpret BMI.
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What this dot point is asking
Edexcel wants you to describe a balanced diet, explain the role of macronutrients and micronutrients, water and fibre, explain carbohydrate loading and protein timing, and calculate and interpret BMI.
A balanced diet and the macronutrients
Micronutrients, water and fibre
Nutrition timing for athletes
Calculating BMI
How diet differs by sport
The right balance of a diet depends on the performer. An endurance athlete (a marathon runner or cyclist) eats a high proportion of carbohydrate to keep glycogen stores topped up for long aerobic efforts. A power or strength athlete (a sprinter, weightlifter or rugby forward) needs more protein to repair and build the muscle that heavy training breaks down. Roughly, a balanced diet is built around carbohydrate for energy, with protein and fat in smaller amounts, plus plenty of fruit, vegetables, water and fibre, but the exact split is adjusted to the demands of the sport.
A poor diet harms a performer in clear ways: too little carbohydrate leaves them short of energy and tiring early; too little protein slows recovery and muscle repair; too much fat or sugar with too little activity causes weight gain and raises the risk of obesity and heart disease. This is why a sports diet is planned around the training load, not eaten by habit.
Exam-style practice questions
Practice questions written in the style of Pearson Edexcel exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
Edexcel 20193 marksExplain the role of carbohydrates, proteins and fats for a sports performer.Show worked answer →
A Component 2 short-answer question. One mark per macronutrient role.
Award marks for: carbohydrates are the main energy source for aerobic and anaerobic activity, stored as glycogen and used during exercise; proteins are needed for the growth and repair of muscle tissue, important after training; fats are a source of energy for low-intensity aerobic activity and provide insulation and protect organs.
Each macronutrient must be matched to its correct role for a performer.
Edexcel 20214 marksA performer is 1.75 m tall and has a mass of 80 kg. Calculate their BMI, and explain one limitation of BMI when applied to a muscular athlete.Show worked answer →
A Component 2 calculation (use of data) question. Marks for the method, the value, the interpretation and the limitation.
Use . A BMI of about 26 falls in the overweight range (25 to 29.9).
The limitation: BMI does not distinguish muscle from fat, so a muscular athlete (such as a rugby forward) can be classed as overweight or obese despite having low body fat, because muscle is dense and heavy. Show the formula, the value and the limitation for full marks.
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Sources & how we know this
- Pearson Edexcel GCSE (9-1) Physical Education (1PE0) specification — Pearson Edexcel (2016)