Nutrition provides the cells of an organism with food, but in a form they can use. Organisms need food to be able to keep their bodies working properly. They also need food to be able to do certain things. Malnutrition can happen when a person doesn't eat the right amount of nutrients. They can get better by changing their diet to have the right amount of the various nutrients.
Different organisms have different food requirements, and they eat different things in order to meet those requirements. Animals that do not eat meat, for example, will have to get certain nutrients like protein from other foods.
A nutrition expert is called a dietician. Nutritionists are different because they don't need the government to recognize them as experts. Anyone can call themselves a nutritionist. The six main types of nutrient are carbohydrates, fats, minerals, protein, vitamins, and water. A macronutrient is a nutrient that needs to be eaten a lot. A micronutrient, such as a vitamin, is needed in smaller amounts but it is still important. Carbohydrates are not needed by the body but most people eat a lot of them.

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