Energy Balance

Question 1

Basal Metabolic Rate (BMR) and Physical Activity Level (PAL)

Answer 1

Energy balance is achieved when the energy consumed from food and drink matches the energy used by the body. Two key factors influence total energy needs:
• Basal Metabolic Rate (BMR) – The amount of energy the body needs to maintain basic life functions (e.g., breathing, circulation, and cell repair) while at rest.
• Physical Activity Level (PAL) – The additional energy required for movement and exercise.

Importance in Determining Energy Requirements:
• A higher BMR means the body uses more energy, even when resting.
• A higher PAL means more energy is needed to fuel physical activity.
• Factors such as age, gender, and body composition affect both BMR and PAL, influencing total daily energy needs.

Question 2

Recommended Percentage of Daily Energy Intake

Answer 2

• Carbohydrates: Should provide 50% of total energy intake (mainly from starch and fiber, with minimal free sugars).
• Fat: Should provide no more than 35% of total energy (with a maximum of 11% from saturated fat).
• Protein: Should provide 15% of total energy intake.
• Alcohol: Provides energy but is not a necessary part of a balanced diet.

Question 3

Sources of Energy: Macronutrients and Alcohol

Answer 3

• Carbohydrates – The body’s main energy source, found in grains, fruits, vegetables, and legumes.
• Proteins – Primarily for growth and repair, but can be used for energy if carbohydrate intake is low. Found in meat, fish, eggs, dairy, and pulses.
• Fats – A concentrated energy source, needed for cell functions and vitamin absorption. Found in oils, nuts, and avocados.
• Alcohol – Provides energy but has no nutritional benefits and excessive intake can contribute to health issues.

Question 4

Factors Affecting Energy Requirements

Answer 4

1. Gender – Males typically have a higher BMR and require more energy than females due to greater muscle mass.
   
   2. Life Stage –
      • Children and teenagers require more energy for growth and development.
      • Adults need steady energy intake to maintain body functions.
      • Elderly people have lower energy needs due to reduced muscle mass and slower metabolism.
   3. Pregnancy and Lactation –
      • Pregnant women need extra energy to support fetal growth.
      • Breastfeeding women require additional energy to produce milk.
   4. Size/Body Weight – Larger individuals generally need more energy to maintain their body weight.
   5. Genetics – Some people naturally have a faster or slower metabolism, affecting their energy needs.
   6. Occupation and Lifestyle –
      • Physically demanding jobs (e.g., construction work) require more energy.
      • Sedentary lifestyles (e.g., office work) require less energy.

Question 5

Energy Imbalance: Deficiency and Excess

Answer 5

• Weight loss due to the body using fat and muscle for energy.
• Fatigue and weakness due to lack of fuel for bodily functions.
• Poor immune function, leading to increased illness risk.
• Stunted growth in children and teenagers.

•	Weight gain and obesity, as excess energy is stored as fat.
•	Increased risk of diet-related diseases, such as type 2 diabetes, heart disease, and high blood pressure.
•	Liver damage (due to excessive alcohol consumption).