Nutrition

Nutrition is the way your body uses food to grow, move, and stay healthy. The food you eat is broken down inside your body into smaller pieces called nutrients. Nutrients give you energy, build new cells, and keep your organs working. Every living thing needs nutrition, but humans get theirs in an unusually wide variety of ways.

Scientists group the nutrients in food into six main types. The first three are called macronutrients because your body needs them in large amounts. Carbohydrates, found in bread, rice, fruit, and pasta, are your main source of quick energy. Proteins, found in meat, beans, eggs, and nuts, build muscles, skin, hair, and almost every part of your body. Fats, found in oils, butter, fish, and avocados, store energy and help your brain work.

The other three groups are needed in much smaller amounts, but they matter just as much. Vitamins help your body do hundreds of jobs, like healing cuts and keeping your eyes sharp. Minerals, such as calcium and iron, build strong bones and carry oxygen in your blood. Water is the sixth nutrient, and your body is more than half water by weight.

Different foods carry different nutrients, so eating a mix is important. A meal with vegetables, fruit, whole grains, and a protein gives your body more of what it needs than a meal of just one food. Doctors often suggest filling about half your plate with fruits and vegetables. The bright colors in plants come from chemicals that help keep your cells healthy.

Nutrition science is younger than you might think. People did not even know vitamins existed until the early 1900s. Sailors used to get a painful disease called scurvy on long voyages because they had no fresh food. In 1747, a Scottish doctor named James Lind proved that lemons and limes could cure it, though no one yet understood why. The answer, vitamin C, was not identified until 1932.

Scientists are still learning. Researchers today argue about how much sugar is too much, whether some fats are healthier than others, and how the bacteria in your gut shape your health. New studies come out every year, and old advice sometimes turns out to be wrong.

Still, the basic idea has not changed in a long time. Eat a variety of real foods, drink water, and do not overdo any one thing. Your body does the rest.