This topic covers the three main macronutrients - carbohydrates, proteins, and fats. Students will learn about the functions of each macronutrient in the body, their sources, recommended daily intake, and how to calculate macronutrient ratios for meal planning.
Understanding Macronutrients
Key nutrients that provide energy and the building blocks for growth, repair, and daily function.
| Macro‑nutrient | Primary Function | Typical Energy Yield* |
|---|---|---|
| Carbohydrates | Quick source of fuel; supports brain and nervous‑system activity | 4 kcal/g |
| Proteins | Building blocks for muscles, enzymes, hormones, antibodies; can be used for energy when needed | 4 kcal/g |
| Fats (Lipids) | Concentrated energy storage; essential for cell‑membrane structure, hormone production, absorption of fat‑soluble vitamins | 9 kcal/g |
*Energy values are average values used for nutrition labeling.
| Category | Examples | Digestibility | Typical Uses |
|---|---|---|---|
| Simple sugars (monosaccharides, disaccharides) | Glucose, fructose, sucrose, lactose | Rapidly absorbed | Quick energy, recovery drinks |
| Complex carbs (oligosaccharides, polysaccharides) | Starch, dietary fiber, glycogen | Slower digestion | Sustained energy, gut health |
Choosing lower‑GI carbs helps maintain stable energy and supports metabolic health.
| Category | Sources | Completeness |
|---|---|---|
| Complete | Animal products (meat, dairy, eggs), soy, quinoa | Contains all essential amino acids |
| Incomplete | Most plant foods (beans, grains, nuts) | Lacks one or more essential amino acids |
Combining complementary plant proteins (e.g., beans + rice) yields a complete amino‑acid profile.