14.1.1 Balanced Diet and Calorific Value (Q&A)

Short Answer Questions

1. What is a balanced diet?
   Answer
   A balanced diet involves consuming all food classes in the right amounts to meet the body's needs.
2. Why is a balanced diet important?
   Answer
   It helps maintain health, provides energy, supports growth, and aids in tissue repair and metabolic processes.
3. Name three factors that influence an individual’s calorie needs.
   Answer
   Body size, age, and physical activity/occupation.
4. What is calorific value?
   Answer
   Calorific value refers to the total energy released when 1g of food is oxidized or combusted.
5. What units are used to measure calorific value?
   Answer
   Calories (cal), kilocalories (kcal), joules (J), and kilojoules (kJ).
6. How many joules are in one calorie?
   Answer
   1 calorie (cal) = 4.2 joules (J).
7. What equipment is used to determine the calorific value of food?
   Answer
   A calorimeter.
8. How does a calorimeter measure calorific value?
   Answer
   The heat released from combusting food increases the temperature of water, which is measured.
9. Which macronutrient has the highest calorific value?
   Answer
   Fats (37.6 kJ g⁻¹).
10. What is the calorific value of carbohydrates?
    Answer
    16.7 kJ g⁻¹.
11. Why are food labels important?
    Answer
    They provide calorie information per serving to help monitor daily intake.
12. What can happen if a person consumes too few calories?
    Answer
    It can lead to weight loss and nutrient deficiencies.
13. What are the effects of excessive calorie intake?
    Answer
    It can lead to obesity, diabetes, and hypertension.
14. What is the formula for calculating the calorific value of food?
    Answer
    Calorific Value = (4.2 J g⁻¹ °C⁻¹ × mass of water × temperature increase) / (mass of food sample) × 1000.
15. Name two healthy eating practices.
    Answer
    Eating a variety of foods and reducing salt, sugar, and fat intake.
16. How can physical activity help maintain a healthy weight?
    Answer
    It helps balance calorie intake and energy expenditure.
17. Why does body size affect calorie requirements?
    Answer
    Larger individuals require more calories to sustain their energy needs.
18. How does climate influence calorie needs?
    Answer
    Cold climates require more calories for body heat production.
19. What is the impact of age on calorie requirements?
    Answer
    Children and teenagers need more calories for growth, while older adults may need fewer calories due to lower metabolism.
20. How does occupation affect calorie intake needs?
    Answer
    Physically active jobs require higher calorie intake than sedentary jobs.

Explanation Questions

1. How does a balanced diet contribute to overall health?
   Answer
   A balanced diet provides essential nutrients for energy, growth, tissue repair, and metabolic functions, reducing the risk of deficiencies and chronic diseases.
2. Why do fats have a higher calorific value than carbohydrates and proteins?
   Answer
   Fats contain more energy-dense molecules and provide 37.6 kJ g⁻¹, whereas carbohydrates and proteins provide 16.7 kJ g⁻¹ each.
3. How does the calorific value of food help in meal planning?
   Answer
   Knowing the calorific value of foods helps individuals balance their energy intake with their energy needs to maintain a healthy weight.
4. Why is it important to understand food labels?
   Answer
   Food labels provide calorie content and nutrient information, allowing consumers to make informed dietary choices.
5. How does excessive calorie intake lead to obesity?
   Answer
   When calorie intake exceeds energy expenditure, the excess energy is stored as fat, leading to weight gain and obesity.
6. Why do active individuals require more calories than sedentary individuals?
   Answer
   Physical activity increases energy expenditure, requiring a higher calorie intake to maintain energy balance.
7. How does malnutrition occur due to an unbalanced diet?
   Answer
   Malnutrition results from consuming too few or too many nutrients, leading to health problems like deficiencies or obesity.
8. What happens if the body’s calorie intake is lower than its energy expenditure?
   Answer
   The body burns stored fat for energy, leading to weight loss. Severe deficits can cause muscle loss and nutrient deficiencies.
9. Why is a variety of foods recommended in a balanced diet?
   Answer
   Different foods provide essential nutrients that support various bodily functions and prevent deficiencies.
10. How does reducing salt and sugar intake promote health?
    Answer
    Lower salt intake reduces the risk of hypertension, while reducing sugar intake prevents obesity and diabetes.