Nutrition Prof. Chandrani Liyanage

What is nutritionScience that studies all the interactions that occur between living organisms and food.It studies the psychological, social, cultural, economic and technological factors that influence which foods we choose to eat.The science of nutrition also studies the biological processes by which we consume food and utilize the nutrients it contains.

What are nutrients?Substances contained in the food that are necessary to maintain life and allow growth and reproduction.Nutrients provide energy, contribute to structure, and regulate biological processes.App 45 nutrients are considered essential to human life.Essential nutrients are those necessary to support life, have to be supplied from food, as can not be made in required quantities to meet the needs.

6 classes of nutrientsCHOProteinFat/lipids Energy yielding nutrients, macro nutrientsVitaminsMinerals micro nutrients needed in very small amountsWater

Non-essential nutrientsPhytochemicals health promoting propertiesLecithin needed for nerve function, can be produced in the body, so, not essential

Antinutrients phytate, polyphenolsAlcohol energy producing but not a nutrientFiber helps in bowel movement

How do nutrients function in the body?CHO (blood glucose)Lipid (stored fuel)Protein (excess protein used for energy)Function energy productionLipid (cell membranes)Protein (connective tissue holds bones and muscles)Minerals (bone and teeth)Function structure formationProtein (leptin for regulation)Water (to cool body to regulate body temp)Vitamins - (B regulate use of macronutrients for energy)Minerals - (Na helps regulate blood volume) Function - regulation

Effects of poor nutrient intakeToo much or too little intake leads to malnutritionDeficiency of energy or nutrients cause undernutritionOccurs due to deficient intake, increased requirements, inability to use or absorb nutrientsStarvation is the most severe form that causes wt loss, poor growth, inability to reproduce and if not treated deathExcess of nutrients lead to overnutrition a form of malnutrition. Extra stored as body fat, (obesity) increasing hypertension, heart disease, diabetes etc.. Toxic reactions occur with excess of specific nutrients