Nutrition and Dietetics — Complete Exercise Solutions
Key Concepts Quick Recap
| Nutrient | Energy | Key Functions | Deficiency |
|---|
| Carbohydrates | 4 kcal/g | Primary energy; spares protein | Ketosis, hypoglycaemia |
| Proteins | 4 kcal/g | Growth, repair, enzymes, antibodies | Kwashiorkor (protein), Marasmus (protein+energy) |
| Fats | 9 kcal/g | Energy, fat-soluble vitamins, insulation | EFA deficiency (skin, reproductive issues) |
| Water | 0 | Transport, temperature regulation | Dehydration |
| Vitamins | 0 | Co-enzymes, antioxidants | Various deficiency diseases |
| Minerals | 0 | Bone, nerve, enzyme function | Anaemia (Fe), Rickets (Ca+D) |
I. Choose the Best Answer (MCQs)
1. The nutrient that provides the highest energy per gram is: (a) Carbohydrates (b) Proteins (c) Fats (d) Vitamins
Answer(c) Fats Fats: 9 kcal/g. Carbohydrates and proteins: 4 kcal/g each. Vitamins and minerals: no energy.
2. Kwashiorkor is caused by: (a) Deficiency of both protein and energy (b) Deficiency of protein with adequate calories (c) Vitamin C deficiency (d) Iron deficiency
Answer(b) Deficiency of protein with adequate calories Kwashiorkor: protein deficiency (but adequate carbohydrate calories). Features: oedema (swelling due to low serum albumin), pot belly, skin depigmentation, apathy. Mainly affects young children weaned on starchy foods. Marasmus: deficiency of both protein AND energy → severe wasting, emaciation.
3. The RDA (Recommended Dietary Allowance) for proteins for an average adult is approximately: (a) 0.3 g/kg body weight (b) 0.8 g/kg body weight (c) 2.0 g/kg body weight (d) 5 g/kg body weight
Answer(b) 0.8 g/kg body weight RDA for protein: 0.8 g/kg/day for sedentary adults. Athletes and pregnant women need more (1.2-2.0 g/kg/day).
4. A diabetic diet should emphasise: (a) High simple sugar, low fat (b) High glycaemic index foods (c) Low glycaemic index foods, high fibre, controlled carbohydrates (d) High fat, no carbohydrate
Answer(c) Low glycaemic index foods, high fibre, controlled carbohydrates Diabetic diet: limit refined carbohydrates; choose whole grains (low GI); high fibre slows glucose absorption; distribute meals evenly throughout the day; limit saturated fats.
5. The Glycaemic Index (GI) measures: (a) Protein quality (b) How quickly a food raises blood glucose (c) Fat content of food (d) Vitamin content
Answer(b) How quickly a food raises blood glucose High GI (>70): white bread, glucose, white rice. Low GI (<55): lentils, oats, most fruits. Medium GI (56-69): whole wheat bread, sweet corn.
6. Iron deficiency leads to: (a) Night blindness (b) Scurvy (c) Iron-deficiency anaemia (d) Pellagra
Answer(c) Iron-deficiency anaemia Iron-deficiency anaemia: most common nutritional deficiency worldwide. Features: pallor, fatigue, breathlessness. Iron needed for haemoglobin synthesis. Rich sources: red meat, organ meat, dark leafy greens, fortified cereals. Vitamin C enhances iron absorption.
7. Which of the following is a therapeutic diet for hypertension? (a) High sodium diet (b) DASH diet (low sodium, high potassium, rich in fruits, vegetables) (c) High fat diet (d) Low fibre diet
Answer(b) DASH diet (low sodium, high potassium, rich in fruits, vegetables) DASH (Dietary Approaches to Stop Hypertension): low sodium (<2300 mg/day), high potassium, magnesium, calcium; emphasises fruits, vegetables, whole grains, low-fat dairy; limits saturated fat.
II. Short Answer Questions
Q1. What are therapeutic diets? Give three examples.
Answer
Therapeutic diet: modified diet prescribed to treat or manage a medical condition.
| Condition | Dietary Modification |
|---|
| Diabetes mellitus | Low GI, controlled carbohydrate, high fibre |
| Hypertension | Low sodium, DASH diet, high potassium |
| Renal disease | Low protein, low potassium, low phosphate, fluid restriction |
| Coeliac disease | Gluten-free diet (no wheat, rye, barley) |
| Phenylketonuria (PKU) | Phenylalanine-restricted diet |
| Obesity | Calorie-restricted, high fibre, low fat |
| Heart disease | Low saturated fat, high unsaturated fat, low cholesterol |
Q2. What is BMR and how is it calculated?
Answer
BMR (Basal Metabolic Rate): energy required by the body at complete rest in a thermoneutral environment for basic functions.
Harris-Benedict equation:
- Males: BMR = 66 + (13.7 × weight in kg) + (5 × height in cm) − (6.8 × age in years)
- Females: BMR = 655 + (9.6 × weight) + (1.8 × height) − (4.7 × age)
Total Daily Energy Expenditure (TDEE) = BMR × Activity factor:
- Sedentary: 1.2; Light activity: 1.375; Moderate: 1.55; Very active: 1.725.
Factors affecting BMR: age (↓), sex (males > females), body composition (muscle ↑), thyroid hormones, fever, body temperature.
Exam Checklist
- Macronutrients: Carbs 4 kcal/g, Proteins 4 kcal/g, Fats 9 kcal/g.
- Kwashiorkor: protein deficiency (oedema, pot belly). Marasmus: protein + energy deficiency (wasting).
- Iron deficiency → anaemia; Iodine → goitre; Vitamin D → rickets; Vitamin C → scurvy.
- GI: high (>70) = rapid glucose rise; low (<55) = slow; diabetics need low GI.
- DASH diet: low sodium, high potassium/fruits/vegetables → treats hypertension.
- BMR: resting energy; Harris-Benedict equation; factors: age, sex, muscle mass.
