Nutrition is the study of how food and drink affect our bodies. It’s about understanding the substances in food, called nutrients, and how they provide energy, help us grow, and keep us healthy. Think of your body as a complex machine. Food is the fuel and the raw material it needs to run properly.

Every single thing your body does, from breathing to thinking, requires nutrients. They are the building blocks for new cells, the power source for your muscles, and the regulators of chemical processes that keep you alive. Without a steady supply of the right nutrients, our bodies can't perform at their best.

Nutrients are divided into two main categories based on how much of them our bodies need. These categories are macronutrients and micronutrients. The prefixes give you a hint: "macro" means large, and "micro" means small.

Macronutrients are the nutrients your body needs in larger amounts. They provide your body with energy, measured in calories. The three macronutrients are carbohydrates, proteins, and fats.

Micronutrients, on the other hand, are needed in much smaller quantities. They don't provide energy, but they are crucial for a vast range of bodily functions, including energy production, immune function, and blood clotting. Vitamins and minerals make up the micronutrients.

Achieving the right balance of these nutrients is key to good health. Both too little and too much of certain nutrients can cause problems.

A nutrient deficiency occurs when the body doesn't get enough of a particular nutrient. This can lead to a variety of health issues, from low energy and poor concentration to more serious conditions affecting bone health, vision, or the immune system.

Conversely, a nutrient excess or toxicity happens when the body has too much of a nutrient. While less common from food alone, this can occur with supplements. Excessive intake of certain vitamins or minerals can be harmful and disrupt the body's normal functions.

Now that you understand the basic categories of nutrients, let's test your knowledge.

Understanding these fundamentals is the first step toward making informed choices about the food you eat and building a foundation for a healthy life.