Nutrition: Nutritious Food Types and Dietary Information
Author: Disabled World (DW)
Updated/Revised Date: 31 Jul 2026
Table of Contents:
Synopsis - Definition - About This Section - FAQs - Publications - Subtopics
Synopsis
A clear guide to human nutrition covering the seven nutrient classes, macro and micronutrients, and how a balanced diet supports health and prevents disease.
At a Glance
- 1 - The seven major nutrient classes are carbohydrates, fats, fiber, minerals, protein, vitamins, and water.
- 2 - Carbohydrates and proteins each supply 4 kilocalories per gram, while fats provide 9 kilocalories per gram.
- 3 - Nutrients divide into macronutrients, needed in larger amounts, and micronutrients such as minerals and vitamins, needed in smaller amounts.
- 4 - Omega-3 and omega-6 are essential fatty acids the body cannot make, and they act as substrates for prostaglandins that function throughout the body.
Topic Definition
- Nutrition
Nutrition is the process by which the body takes in and uses food to meet its dietary needs, and it sits at the very heart of good health. Sound nutrition means eating an adequate, well balanced diet, combined with regular physical activity, so the body receives enough energy and the raw materials it needs to grow, repair itself, and function properly. The nutrients that make this possible fall into seven classes - carbohydrates, fats, fiber, minerals, protein, vitamins, and water - which are further grouped into macronutrients needed in larger amounts and micronutrients needed only in small quantities. When nutrition is poor, the consequences can include weakened immunity, greater vulnerability to disease, and impaired physical and mental development, whereas a varied, nutritious diet is repeatedly shown to protect health, support healthy development in children, and help prevent a range of illnesses.
Overview
Nutrition is defined as the intake of food, considered relating to the body's dietary needs. Good nutrition - an adequate, well-balanced diet combined with regular physical activity - is a cornerstone of good health. Poor nutrition can lead to reduced immunity, increased susceptibility to disease, impaired physical and mental development, and reduced productivity. The diet of an organism is what it eats, which is largely determined by the availability, processing, and palatability of foods. A healthy diet includes preparation of food and storage methods that preserve nutrients from oxidation, heat or leaching, and that reduce risk of foodborne illnesses.
Eating a healthy, nutritious diet has been shown over and over to prevent a variety of diseases, including cancer. Good nutrition is vital to good health, disease prevention, and essential for healthy growth and development of children and adolescents.
Nutrient Classes
There are seven major classes of nutrients: carbohydrates, fats, fiber, minerals, protein, vitamins, and water.
- Carbohydrates - our main source of energy.
- Fats - one source of energy and important relating to fat soluble vitamins.
- Roughage (Fiber) - the fibrous indigestible portion of our diet essential to health of the digestive system.
- Minerals - those inorganic elements occurring in the body and which are critical to its normal functions.
- Proteins - essential to growth and repair of muscle and other body tissues.
- Vitamins - water and fat soluble vitamins play important roles in many chemical processes in the body.
- Water - essential to normal body function - as a vehicle for carrying other nutrients and because 60% of the human body is water.
These nutrient classes can be categorized as either;
- Macro-nutrients (needed in relatively large amounts) - The macro-nutrients are carbohydrates, fats, fiber, proteins, and water.
- Micro-nutrients (needed in smaller quantities) - The micro-nutrients are minerals and vitamins.
The macro-nutrients (excluding fiber and water) provide energy, which is measured in Joules or kilo-calories (often just called Calories).
Carbohydrates and proteins provide 17 kJ (4 kcal) of energy per gram, while fats provide 37 kJ (9 kcal) per gram.
Vitamins, minerals, fiber, and water do not provide energy, but are necessary for other reasons.
The human body contains chemical compounds, such as water, carbohydrates (sugar, starch, and fiber), amino acids (in proteins), fatty acids (in lipids), and nucleic acids (DNA and RNA). These compounds in turn consist of elements such as carbon, hydrogen, oxygen, nitrogen, phosphorus, calcium, iron, zinc, magnesium, manganese, and so on. All of these chemical compounds and elements occur in various forms and combinations (e.g., hormones, vitamins, phospholipids, hydroxyapatite), both in the human body and in the plant and animal organisms that humans eat.
Water is one of the most important nutrients in your diet. It helps eliminate food waste products in your body, regulates body temperature during activity, and helps digest food.
Fatty Acids
Most fatty acids are non-essential, meaning the body can produce them as needed. However, in humans, at least two fatty acids are essential and must be included in the diet. An appropriate balance of essential fatty acids, Omega-3 and omega-6 fatty acids, is critical for health. Both of these "omega" long-chain polyunsaturated fatty acids are substrates for a class of eicosanoids known as prostaglandins, which have roles throughout the human body.
Phytochemicals
A growing area of interest is the effect upon human health of trace chemicals, collectively called phytochemicals. These nutrients are typically found in edible plants, especially colorful fruits and vegetables, but also other organisms including seafood, algae, and fungi.
The effects of phytochemicals increasingly survive rigorous testing by prominent health organizations. One of the principal classes of phytochemicals are polyphenol antioxidants, chemicals which are known to provide certain health benefits to the cardiovascular system and immune system. These chemicals are known to down-regulate the formation of reactive oxygen species, key chemicals in cardiovascular disease.
Eat Nutritiously
Learning to eat nutritiously is not hard. The key is to:
- Drink lots of water.
- Go easy on the salt, sugar, alcohol, saturated fat and trans fat.
- Eat a variety of foods, including fruits and vegetables, and whole-grain products.
- Eat lean meats, poultry, fish, beans and low-fat dairy products.
Frequently Asked Questions
What is the difference between nutrition and diet
Nutrition is how the body takes in and uses nutrients from food, while a diet is the particular pattern of foods a person actually eats.
How much water should I drink each day
Needs vary with age, activity, climate, and health, but a common general guide is around six to eight glasses a day, adjusted for thirst and individual circumstances.
Are all fats bad for you
No, the body needs some fats for energy and to absorb fat soluble vitamins, and the aim is to favor unsaturated fats while limiting saturated and trans fats.
What are antioxidants and why do they matter
Antioxidants are compounds that help neutralize reactive molecules linked to cell damage, and they are found in many colorful fruits and vegetables.
Do I need supplements if I eat a balanced diet
Most people who eat a varied balanced diet get enough nutrients from food, though some individuals may need supplements on the advice of a health professional.
How can I get enough protein on a plant based diet
You can combine sources such as beans, lentils, tofu, nuts, seeds, and whole grains to obtain the full range of amino acids your body needs.
Why is fiber important in the diet
Fiber supports healthy digestion, helps regulate blood sugar and cholesterol, and promotes a feeling of fullness that can aid weight management.
Curated and edited by Ian C. Langtree, Founder & Editor-in-Chief, Disabled World. This section is maintained by the Disabled World editorial team.
Last updated: