DESCRIBING NUTRIENTS HFN 20

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 classes of nutrients. –Essential or nonessential –Organic or inorganic –Macronutrient or micronutrient –Energy yielding or not

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

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 restores the biological function

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

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 ■Where does the energy come from?

A little more on energy ■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 1 0 C ■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

■Carbohydrates: ■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 ■Carbohydrate rich foods……..

Lipids ■Lipids – fats and oils: ■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 – solids ■Oils – liquids ■Saturated (solids/fats) –No carbon to carbon double bonds ■Unsaturated (liquids/oils) –Carbon to carbon double bond(s) present ■Lipid rich foods?

Proteins ■Proteins: ■4 kcal/gram (same as _______) –Body’s least desirable source of energy ■WHY? ……. –Protein is used for energy only when carbohydrate is NOT available as an energy source. –Protein rich foods?

Energy-Yielding Non-nutrient ■Alcohol – 7 kcal/gram ■Non-nutrient because it interferes with growth, maintenance and repair of the body –Alcohol’s metabolites are harmful

Nutrient Density ■Food supplies both nutrients and calories (energy). ■All calories come from only three elements: carbohydrates, fats, and proteins. ■Micronutrients, on the other hand, are non-caloric food factors, such as vitamins, minerals, fibers, and antioxidants. These non-caloric nutrients are vitally important for good health. ■The key to optimizing your health and achieving your ideal body weight is to eat predominantly those foods that have a relatively high proportion of nutrients (non-caloric food factors) to calories (carbohydrates, fats, and proteins).

Understanding Nutrient Density ■Let's compare and contrast the nutrients we will get when choosing between an apple and a bag of potato chips….. ■ vs.

■An apple will provide: –dietary fiber (soluble and insoluble fiber) –Vitamins –Minerals –antioxidants –80 calories. ■Potato chips come with: –saturated fats –No fiber –No antioxidants –No vitamins or minerals. –more than 200 calories

■An apple provides the most nutrients along with its 80 calories, while the potato chips yield more calories than nutrients. ■An apple will appease your hunger until lunch, but the odds of not feeling full and reaching for another bag of chips is high. ■So with more nutrients per calorie, an apple is clearly the nutrient-dense choice. ■APPLE= NUTRIENT DENSE (fewer calories, more nutrients) ■CHIPS = EMPTY CALORIES (more calories, very few/no nutrients)

Variables which affect nutrient needs: 1. Age 2. Gender 3. Activity Level 4. Climate 5. Health 6. State of nutrition