Energy - Role of Energy in the Body

Introduction

• Energy is crucial for the human body as it powers all bodily functions and activities.
• It is derived from the food we eat, particularly carbohydrates, proteins, and fats.

Sources of Energy

Carbohydrates

Primary source of energy, especially important for brain function.

Fats

Dense energy source, also essential for cell structure and the absorption of fat-soluble vitamins.

Proteins

Generally used for body repair and growth, can be an energy source when necessary.

Basal Metabolic Rate (BMR)

Definition

The amount of energy expended while at rest in a neutrally temperate environment.

• BMR is the minimum energy required to sustain essential physiological functions such as breathing, circulation, and cell production.
• Factors affecting BMR: Age, gender, genetics, body composition, and hormonal balance.

Energy for Growth

• Energy is vital for growth processes, including cellular growth and repair.
• Adolescents, pregnant women, and children have higher energy needs due to growth demands.

Energy and Physical Activity

• Physical activity significantly increases the body's energy requirements.
• The intensity and duration of the activity determine the amount of energy expended.

Measuring Energy

• Energy in food is measured in kilocalories (kcal) or kilojoules (kJ).
• The energy requirement varies based on age, sex, activity level, and individual metabolic rate.

Energy Balance and Health

• Maintaining energy balance (energy intake equals energy expenditure) is crucial for healthy body weight.
• Imbalance can lead to underweight or overweight conditions, affecting overall health.

Dietary Recommendations

• Balanced diet with appropriate proportions of carbohydrates, fats, and proteins.
• Consideration for dietary fibre and micronutrients for overall health.

Example Exam Question and Answer