An Overview of Nutrition Assist. Prof Dr. Lujain A. Alkhazrajy
Nutrition: the process by which a living organism assimilates food and uses it for growth and maintenance of tissues Nutrients- components of food: Provide energy Provide structural materials Provide regulatory agents that support cell growth, maintenance, and repair of tissues May reduce the risk of certain diseases
Nutrition : the science of food, the nutrients and the substances there in, their action, interaction, and balance in relation to health and disease, and the process by which the organism ingests, absorbs, transport, utilizes, and excretes food substances ---- The Council on Food and Nutrition of the American Medical Association 3
Actions in the body include: Ingestion Digestion Absorption Transport Metabolism Excretion 4
Nutritional Goals Quality intake: that allows you to function at your best and promotes health. Intake that provides adequate levels of each nutrient Quantity of intake that promotes a healthy body weight. 5
Diet and Health Diet - the foods one consumes The quality of your daily diet affects the risk of chronic diseases Meaning..The food choices you make daily have a cumulative impact on your health 6
Nutrition and Health Nutrition plays a central role in all life functions Animals often spend a large amount of time and energy obtaining food and feeding, but we humans do not Nowadays we can choose between nutritious/nonnutritious foods Food choice makes a big difference to our health and the risk of: deficiency under nutrition,excess over nutrition Our food choices are determined by: - habits usually established in childhood - personal likes and dislikes - cost of food - convenience of shopping and preparing - education about what is nutritious and healthy
Nutrition and Health Chronic health issues associated with diet include: Cardiovascular disease Hypertension Obesity Type II Diabetes Osteoporosis 8
What s Considered Food? Foods contain nutrients and are derived from plant or animal sources Nutrients are used by the body to provide energy and to support growth, maintenance and repair of body tissues ~ 40 nutrients identified at this time 9
Classifying Nutrients There are 6 Classes of Nutrients 1. Carbohydrates 2. Lipids (fats) 3. Proteins 4. Vitamins 5. Minerals 6. Water 10
Body Composition 11
Describing the Nutrients There are several ways to classify the classes of nutrients: Essential or nonessential Organic or inorganic Macronutrient or micronutrient Energy yielding or not 12
Classifying Nutrients Essential nutrients nutrients the body either cannot make or cannot make enough of to meet its needs. These nutrients must be obtained from foods (ingested in some manner) Examples: Vitamins Calcium, iron, and other minerals Some of the amino acids 13
if deficient the loss of function is, in the short term, reversible by the specific nutrient The Six Criteria for Nutrient Essentiality The nutrient. is essential for one or more of the (8) functions of life is not synthesized or synthesized adequately in the body has a function that is either biochemical or structural if deficient, a recognizable loss of function or structure results if deficient the loss of function or structure is proportional to degree and duration of depletion
Essential Nutrients and Life Functions Life Functions Key Essential Nutrients Movement Calcium and vitamin D bones, Protein and potassium - muscles Respiration Vitamin B metabolism, iron oxygen transport, Iodine thyroid hormone and metabolic rate Sensitivity B vitamins - central and peripheral nerves Iron and iodine - intellectual development Nutrition Zinc and iron - appetite Excretion Water, sodium and potassium - urine excretion Reproduction Iron and B vitamins fertility and pregnancy outcome Growth Energy, protein, iron, zinc, vitamin A infant growth Defence Protein, vitamin A and zinc - immune function
Classifying Nutrients Nonessential nutrients body can make from other nutrients ingested Examples: Cholesterol Some amino acids 16
Classifying Nutrients by Composition Organic nutrients - contain carbon Carbohydrates Lipids Proteins Vitamins Inorganic nutrients - do not contain carbon Minerals Water 17
The Nutrients Copyright 2005 Wadsworth Group, a division of Thomson Learning
Quantity Needed Macronutrients: need in relatively large amounts Carbohydrates, lipids, proteins Micronutrients: need in relatively small amounts All other nutrients 19
Classifying Nutrients Energy-yielding nutrients (3): Carbohydrates Fats (lipids) Proteins Where does the energy come from? 20
Food guide pyramid In 1992, the USDA (United States Department of Agriculture) adopted the nutritional guide that was created at Tufts University. It is in the shape of a pyramid, to help people remember what food to eat. The pyramid looks like this:
This pyramid shows different food groups, and the servings you should have of each. For example, you should have 6 to 11 servings a day of foods in the Bread, Cereal, Rice & Pasta Group Notice that the bottom of the pyramid, the biggest part, is the Bread, Cereal, Rice & Pasta Group. This pyramid shows that that is where you should get the most servings per day. The top part, the Fats, Oils & Sweets Group is the smallest. That shows that you shouldn't have too much fat or oil in your diet.
Serving size: 1. The portion of food used as a reference on the nutrition label of that food. 2. The recommended portion of food to be eaten.
In April 2005, the USDA replaced the original pyramid with another pyramid by turning it on its side and making the sections vertical instead of horizontal. Looking at this pyramid, there are different colored parts of the pyramid, but each one gets smaller as it goes toward the top. The part toward the top is for the less healthy foods in the category, and the part at the bottom is for the healthier foods..
For example, you might put whole milk at the top of the Milk group, and non-fat milk at the bottom; or you could put whole grains at the bottom of the Grains group and refined grains at the top. The parts of the pyramid also show how important they are by the width of the band. The small yellow one that has no name on the bottom contains fats and oils. The unsaturated oils, like peanut, canola, or olive, would be at the bottom. Butter would be at the top. The person climbing the steps on the left side of the pyramid symbolizes the importance of exercise.
Faculty members at the Harvard School of Public Health made an alternate pyramid, which they called the Healthy Eating Pyramid. Notice this pyramid has a section on the bottom called Daily Exercise and Weight Control. It is built this way to show that daily exercise and weight control are the foundation for good health.