Introduction to Human Nutrition

Real Hope for Haiti – Clinic for Malnourished Children

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.

Nutrition Defined Nutrition – the science that links foods to health and disease Study processes by which nutrients are Ingested Digested Absorbed Transported Metabolized Excreted

What’s Considered Food? Foods contain nutrients and are derived from plant or animal sources Nutrients – substances in foods that are needed for growth and maintenance of a heathy body ~ 40 nutrients identified at this time

Essential Nutrients To be classified as an essential nutrient: The biological function of nutrient is known Omission from the diet leads to a decline in a biological function Return of the nutrient before permanent damage is done restores the biological function

Classifying Nutrients Essential nutrients – another way to think about… nutrients the body either cannot make or cannot make enough of to maintain health These nutrients must be obtained from foods (ingested in some manner) Examples: Vitamins Calcium, iron, and other minerals Some of the amino acids

Classifying Nutrients Nonessential nutrients – body can make from other nutrients ingested  Examples: Cholesterol Some amino acids

Classifying Nutrients There are 6 Classes of Nutrients 1. Carbohydrates 2. Lipids (fats) 3. Proteins 4. Vitamins 5. Minerals 6. Water

Body Composition

Describing the Nutrients There are several ways to classify the 6 classes of nutrients. Essential or nonessential Organic or inorganic Macronutrient or micronutrient Energy yielding or not Promote growth, development, maintenance Regulate body functions

Classifying Nutrients by Composition Organic nutrients - contain carbon Carbohydrates Lipids Proteins Vitamins Inorganic nutrients - do not contain carbon Minerals Water

Quantity Needed Macronutrients: need in relatively large amounts Carbohydrates, lipids, proteins Micronutrients: need in relatively small amounts All other nutrients

Classifying Nutrients Energy-yielding nutrients (3): Carbohydrates Fats (lipids) Proteins

Nutrients 1. Carbohydrates: C, H, O 4 kcal/gram Body’s primary source of energy Use as glucose Glucose is the brain’s only source of energy Carbohydrate stores are limited ~12-24 hours (in liver and muscle)

Classes of Carbohydrates Simple sugars Monosaccharides and disaccharides Complex carbohydrates Starch Fibers – cannot be digested, pass through system

Carbohydrate rich foods? Simple Complex Fiber

Lipids 2. Lipids – fats and oils: C, H, O 9 kcal/gram Body’s alternate source of energy Use fat along with glucose as an energy source most of the time Stores are unlimited

Types of Lipids Fats Oils Solids at room temperature Mostly animal sources Animal sources of fats contain the lipid cholesterol Associated with health issues Oils Liquids at room temperature Plant sources, fish oils Contain essential fatty acids

Other Lipids Cholesterol Trans fats Non-essential nutrient Animal sources only Associated with cardiovascular disease Trans fats Made when unsaturated oils are processed Hydrogenation reaction makes trans fats Associated with health issues

Lipid Rich Foods?

Proteins Proteins: C, H, O, N, S Primary function is structural Muscles, bones, hair, antibodies, hemoglobin, enzymes….. 4 kcal/gram (same as _______) Body’s least desirable source of energy Protein is used for energy only when carbohydrate is NOT available as an energy source.

Classes of Proteins Proteins are made of ~20 amino acids 9 of these are essential Complete proteins – contain all 9 essential amino acids Incomplete proteins – lacking one of more essential amino acids

Protein Rich Foods? Animal proteins Plant Proteins Source of complete protein Meat, poultry, fish, eggs, dairy Plant Proteins Source of incomplete protein Grains, beans (legumes), nuts, seeds, some vegatables

6 Classes of Nutrients Carbohydrates Lipids (fats and oils) Proteins Vitamins Minerals Water

Vitamins Essential Organic, micronutrient Not energy-yielding (no calories) 2 classes of vitamins: water-soluble fat-soluble

Minerals Essential Inorganic, micronutrient Not energy-yielding Major minerals: eg..Ca, P, Na Trace minerals: eg…Fe, Zn Not energy-yielding Indestructible, can be lost in cooking water Structural functions, some are electrolytes – play role in muscle and nerve function

Water Water (H2O) Essential Organic or inorganic? Noncaloric We are ~60% water

Not everyone has access to clean water

Other Components of Foods Phytochemicals – chemicals found in plants that are associated with health Not considered essential nutrients See page 14

Energy-Yielding Non-nutrient Alcohol – 7 kcal/gram Not an essential nutrient because it does not have any required functions in the body

A little more on energy Where does the energy come from? Measure energy in kilocalories in U.S. What most think of as a “calorie” is really a kilocalorie Kcal = amount of energy needed to raise the temperature of 1 kg of water by 10C Measure energy in kilojoules (kJ) in most other countries

Energy in the Body The body uses the energy yielding nutrients to fuel all activities All energy yielding nutrients are “caloric”. If more energy is ingested than is needed to fuel body activities the extra energy is stored as _________ and ________ occurs.

Energy-Yielding Nutrients

Evaluating a Food Label _____ grams carbohydrate _____ grams fat _____ grams protein TOTAL KCAL: ____________

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

Nutrition and Health Chronic health issues associated with diet include: Heart disease Hypertension Obesity Type II Diabetes Osteoporosis

Improving your Health Goal is to reduce the number of risk factors that are in your control Risk factor = something that statistically increases the incidence of a disease Risk factors may not be the cause of the disease

Leading Causes Death - U.S. (2014) Heart disease: 614,348 Cancer: 591,699 Chronic lower respiratory diseases: 147,101 Accidents (unintentional injuries): 136,053 Stroke (cerebrovascular diseases): 133,103 Alzheimer's disease: 93,541 Diabetes: 76,488 Influenza and pneumonia: 55,227 Kidney disease: 48,146 Intentional self-harm (suicide): 42,773

Obesity in the United States Obesity plays a role in chronic health issues Diabetes Heart disease Stroke Hypertension Some cancers High cholesterol

Obesity in the U.S. (2015)

Improving Health Risk factors you cannot control: Age Gender Genetics (family history) Ethnicity

Improving Health Risk factors in your control: Smoking Alcohol intake Over-consumption of calories Physical inactivity Poor quality diet

Healthy People 2020 Focuses on: Healthy eating patterns Healthy physical activity patterns Healthy weight

Healthy People 2020 Americans with a healthful diet: Consume a variety of nutrient-dense foods within and across the food groups, especially: whole grains, fruits, vegetables, low-fat or fat-free milk or milk products, and lean meats and other protein sources.

Healthy People 2020 Americans with a healthful diet: Limit the intake of saturated and trans fats, cholesterol, added sugars, sodium (salt), and alcohol.

Food Choices Small group exercise What influences your food choices each day? Why do you eat what you eat? Get into groups of ~4 and make a list of what impacts your food choices most days.