Nutrition
Overview
Nutrition is the science that interprets the interaction of nutrients and other substances in food in relation to maintenance, growth, reproduction, health and disease of an organism. It includes food intake, absorption, assimilation, biosynthesis, catabolism and excretion.
The diet of an organism is what it eats, which is largely determined by the availability and palatability of foods. For humans, a healthy diet includes preparation of food and storage methods that preserve nutrients from oxidation, heat or leaching, and that reduces risk of foodborne illnesses.
Nutrients
A nutrient is a source of nourishment, a component in foods that an organism uses to survive and grow. Macronutrients are consumed in relatively large quantities and include proteins, carbohydrates, and fats and fatty acids. Micronutrients are consumed in smaller quantities and include vitamins and minerals.
Macronutrients
The macronutrients are carbohydrates, fiber, fats, protein, and water. The macronutrients (excluding water) provide structural material (amino acids from which proteins are built, and lipids from which cell membranes and some signaling molecules are built) and energy.
Carbohydrates
Carbohydrates may be classified as monosaccharides, disaccharides, or polysaccharides depending on the number of monomer (sugar) units they contain. They constitute a large part of foods such as rice, noodles, bread, and other grain-based products.
Fats
Fats are triglycerides, made of assorted fatty acid monomers bound to a glycerol backbone. Some fatty acids, but not all, are essential in the diet: they cannot be synthesized in the body.
Proteins
Proteins are the basis of many animal body structures (e.g. muscles, skin, and hair). They also form the enzymes that control chemical reactions throughout the body. Each protein molecule is composed of amino acids, which are characterized by inclusion of nitrogen and sometimes sulphur.
Water
Water is a critical nutrient for health. It is a vital nutrient to the life of every cell, acts first as a building material.
Micronutrients
Micronutrients are essential elements required by organisms in varying quantities throughout life to orchestrate a range of physiological functions to maintain health. Micronutrient requirements differ between organisms; for example, humans and other animals require numerous vitamins and dietary minerals, whereas plants require specific minerals.
Dietary habits and choices
Dietary habits and choices play a significant role in the quality of life, health and longevity. There are many dietary patterns that can lead to health and others that can lead to illness.
Dietary patterns
A healthy diet includes a variety of plant-based and animal-based foods that provide nutrients to the body. Such nutrients give you energy and keep your heart beating, your brain active, and your muscles working.
Eating disorders
An eating disorder is a mental disorder that interferes with normal food consumption. It is defined by abnormal eating habits that may involve either insufficient or excessive diet.
Nutritional science
Nutritional science investigates the metabolic and physiological responses of the body to diet. With advances in the fields of molecular biology, biochemistry, nutritional immunology, molecular medicine and genetics, the study of nutrition is increasingly concerned with metabolism and metabolic pathways.