Plant foods contain thousands of natural chemicals, which are called phytonutrients or phytochemicals("phyto" means "plant"). These chemicals help protect plants from germs, fungi, bugs, and other threats. Phytonutrients are not essential, but they may help prevent disease.
More than 25,000 phytochemicals are found in plant foods, and six important phytonutrients are:
Undernutrition is a form of malnutrition. (Malnutrition also includes overnutrition).
Undernutrition can result from:
inadequate ingestion of nutrients,
loss of nutrients due to diarrhea,
increased nutritional requirements.
Undernutrition progresses in stages: it may develop slowly when it is due to anorexia or very rapidly. First, nutrient levels in blood and tissues change, followed by intracellular changes in biochemical functions and structure. Ultimately, symptoms and signs appear. Diagnosis is by history, physical examination, body composition analysis, and sometimes laboratory tests.
Undernutrition from micronutrient deficiencies, or "hidden hunger", affects over 2 billion people globally and can lead to reduced growth and cognitive development, birth defects, blindness, and overall poor health. Vitamin A deficiency, iron deficiency anaemia and iodine deficiency disorders are among the most common forms of micronutrient malnutrition.