This topic introduces the concept of nutrition, including the essential nutrients, macronutrients, and micronutrients required for optimal health. It covers the importance of a balanced diet and the role of nutrition in overall wellbeing.
Overview of Nutrition – Study Notes
| Category | Primary Function | Key Sources |
|---|---|---|
| Carbohydrates | Quick energy; spare protein for tissue building | Grains, fruits, vegetables, legumes, sugars |
| Proteins | Tissue repair, enzyme & hormone synthesis, immune function | Meat, fish, eggs, dairy, beans, nuts, soy |
| Fats (Lipids) | Concentrated energy, cell‑membrane structure, absorption of fat‑soluble vitamins (A, D, E, K) | Oils, butter, nuts, seeds, fatty fish, avocado |
| Vitamins | Co‑enzymes & regulators of metabolic pathways | Fruits, vegetables, fortified foods, dairy |
| Minerals | Structural (e.g., calcium for bone), electrolyte balance, enzyme cofactors | Dairy, leafy greens, meat, whole grains, nuts |
| Water | Solvent for biochemical reactions, temperature regulation, transport of nutrients & waste | Plain water, beverages, high‑water foods (cucumber, watermelon) |
| Concept | Description |
|---|---|
| Caloric intake | Energy supplied by foods (kcal or kJ). |
| Caloric expenditure | Energy used for basal metabolism, physical activity, thermic effect of food. |
| Energy balance equation | Energy In – Energy Out = Change in Body Stores. • Positive balance → weight gain • Negative balance → weight loss • Neutral balance → weight maintenance |
| Nutrient | % of Total Daily Calories | grams per 2,000‑kcal diet |
|---|---|---|
| Carbohydrates | 45–65% | 225–325 g |
| Protein | 10–35% | 50–175 g |
| Fat | 20–35% | 44–78 g |
| • Saturated fat | <10% of total calories | – |
| • Trans fat | As low as possible | – |
| • Added sugars | <10% of total calories | – |
Adjustments are needed for athletes, pregnant/lactating women, older adults, and people with specific health conditions.
| Vitamin / Mineral | Major Role | Typical Deficiency Signs |
|---|---|---|
| Vitamin A | Vision, immune function | Night blindness, dry skin |
| Vitamin C | Antioxidant, collagen synthesis | Scurvy (bleeding gums, fatigue) |
| Vitamin D | Calcium absorption, bone health | Rickets/osteomalacia, muscle weakness |
| Vitamin E | Antioxidant, membrane protection | Neuromuscular problems |
| Vitamin K | Blood clotting | Excessive bleeding |
| Calcium | Bone & teeth mineralization | Osteoporosis, muscle cramps |
| Iron | Hemoglobin formation, oxygen transport | Anemia, fatigue |
| Zinc | Immune function, DNA synthesis | Growth retardation, impaired wound healing |
| Iodine | Thyroid hormone production | Goiter, hypothyroidism |