Introduction to essential nutrients, macronutrients, micronutrients, and their roles in the body. Understanding the importance of a balanced diet for overall health and well-being.
Basics of Nutrition – Quick Reference Notes
| Category | Primary Function | Key Sources |
|---|---|---|
| Carbohydrates | • Main energy source (4 kcal/g) • Spare protein for growth/repair |
Grains, fruits, vegetables, legumes, sugars |
| Proteins | • Build/repair tissues (muscle, enzymes, hormones) • Provide 4 kcal/g • Supply essential amino acids |
Meat, fish, eggs, dairy, beans, nuts, soy |
| Fats (Lipids) | • Concentrated energy (9 kcal/g) • Cell‑membrane structure • Absorb fat‑soluble vitamins (A, D, E, K) |
Oils, butter, nuts, seeds, avocados, fatty fish |
| Vitamins | • Regulate metabolism, immunity, vision, blood clotting, etc. | Fruits, vegetables, dairy, fortified foods |
| Minerals | • Bone health, nerve transmission, fluid balance, enzyme function | Dairy, meat, whole grains, leafy greens, nuts |
| Water | • Solvent for biochemical reactions • Temperature regulation • Transport of nutrients & waste |
Drinking water, soups, fruits, vegetables |
Caloric Intake vs. Expenditure
Basal Metabolic Rate (BMR): Energy needed at rest.
Physical Activity Level (PAL): Adjusts total energy needs.
| Nutrient | Approx. Daily Amount* |
|---|---|
| Calories | 2,000–2,500 kcal (varies by sex, age, activity) |
| Carbohydrates | 45–65 % of total kcal (≈ 225–325 g) |
| Protein | 0.8 g/kg body weight (≈ 46 g women, 56 g men) |
| Fat | 20–35 % of total kcal (≈ 44–78 g) |
| Fiber | 25 g women, 38 g men |
| Water | 2.7 L women, 3.7 L men (all fluids) |
| Vitamins & Minerals | Based on RDA/AI values (e.g., Vitamin C 90 mg, Calcium 1,000 mg) |
*Values are averages; individual needs may differ.
| Carbohydrates | Protein | Fat |
|---|---|---|
| Complex (starches, fiber) → slower glucose rise | Complete (all essential amino acids) → animal sources; combine plant foods for completeness | Unsaturated (mono‑ & poly‑unsaturated) → heart‑healthy; limit saturated & trans fats |
| Simple (sugars) → quick energy, watch excess | Incomplete → missing one or more essential amino acids (most plant proteins) | ** |