5. Nutrition: Calories, Vitamins & Minerals

Food gives the body both energy and the building materials it needs. Nutrition is where biology meets daily health.

• Calories measure the energy in food.
• Carbohydrates are often a quick energy source; fats store concentrated energy.
• Proteins mainly build and repair tissues and form enzymes.
• Vitamins and minerals usually provide no calories but help body processes work. Calcium supports bones; iron helps red blood cells carry oxygen.
• Water is needed for transport and reactions.

A balanced diet supplies both energy and materials. Too little energy can limit growth and repair; too little of a key vitamin or mineral can disrupt a specific body process. GED® questions usually give a nutrition table — use the data provided.

⚠️ Common misconception: calories are not 'bad.' A calorie is a unit of energy. Health depends on the amount and balance of what you eat, and on getting the nutrients your body needs.

💡 Tip: carbs & fats = energy; protein = build & repair; vitamins & minerals = help processes.