## TL;DR
Nutrition science studies how food components affect human health. The balance of macronutrients (carbs, proteins, fats) and adequacy of micronutrients (vitamins, minerals) determine physiological function and disease risk.

## Core Explanation
Macronutrients: carbohydrates — simple (sugars) vs complex (starches, fiber). Glycemic index measures blood sugar response. Proteins — composed of 20 amino acids (9 essential, must come from diet). Fats — saturated (solid at room temp), unsaturated (liquid), trans (industrial, harmful). Micronutrients: vitamins (A, B-complex, C, D, E, K) and minerals (calcium, iron, zinc, iodine).

## Detailed Analysis
Dietary patterns: Mediterranean (olive oil, vegetables, fish — associated with 25-30% CVD reduction), DASH (hypertension reduction), plant-based. The double burden of malnutrition — undernutrition and obesity coexisting — affects many developing nations.

## Further Reading
- Harvard Nutrition Source
- USDA Dietary Guidelines
- FAO: Food-Based Dietary Guidelines