Look at the nutrition labels for the two breakfast bars below, also paying close attention to the ingredient lists provided in each. Answer the following questions: What is the dif

Dietary Guidelines ● Using various research methods, scientists have been able to estimate the amount of many nutrients

required by the human body. ● A nutrient requirement is defined as the smallest amount of a nutrient that maintains a defined level

of nutritional health. ○ In general, this amount (when consumed daily) prevents the nutrient’s deficiency disease. ○ Ex: the recommended daily amount of

vitamin C (in order to prevent scurvy) is 90 mg for adult men and 75 mg for adult women

● The requirement for a particular nutrient varies to some degree from person to person.

● Factors that may influence a person’s nutrient requirements:

○ Age

○ Gender

○ General health status

○ Physical activity level

○ Use of medications and drugs

Dietary Reference Intakes (DRIs)

● Developed by the Food and Nutrition Board (FNB) of the Institute of Medicine

● Adjusted periodically as new information concerning health and nutrition become available

● Intended to help people:

○ reduce their risk of nutrient deficiencies and excesses

○ prevent disease

○ achieve optimal health

● The standards are the:

○ Estimated Average Requirement (EAR)

○ Recommended Dietary Allowance (RDA)

○ Adequate Intake (AI)

○ Tolerable Upper Intake Level (UL)

○ Estimated Energy Requirement (EER) *considers the person’s

physical activity, height, weight, gender, life stage (energy needs may be

higher or lower for some people); discuss this later in the course

Summary of DRIs

● EAR: amount of a nutrient that meets the needs of 50% of healthy people who are in a particular life stage/sex group

○ Ex: 75 mg/day of vitamin C for males, 60 mg/day for females ages 19-50

● RDA: amount of a nutrient that meets the needs of nearly all healthy individuals in a particular life stage/sex group

○ Ex: 90 mg/day for males (nonsmokers) and 75 mg/day for females ages 19-50 (nonsmokers)

● AI: amount of a nutrient considered to be adequate based on the population’s typical intakes, but not enough info available

to determine an RDA for the nutrient at this time

○ Ex: 40 mg/day of vitamin C for infants ages birth-6 months

● UL: highest average amount of a nutrient that is unlikely to harm

most people when the amount is consumed daily

○ Ex: 2000 mg/day of vitamin C for adults

Food Groups: ChooseMyPlate

Dairy Grains Fruits milk made from whole or cut-up yogurt wheat, rice, contain more cheese oats (pasta, dietary fiber than

bread, cereal) juice, but all are good source of phytochemicals

Proteins Vegetables beef, pork, lamb, poultry, dark green, orange, fish, shellfish; beans, eggs, starchy nuts are also protein-rich

Body Basics

The human body is composed of many organ systems which all work together to promote healthy functioning of the body.

1) integumentary – skin, hair, skin glands: protection, secretion

2) skeletal – 206 bones: movement, protection, mineral storage

3) muscular – over 600 muscles: movement, heat production, glycogen storage

4) nervous – brain, spinal cord, nerves: communication, control, respond to stimuli

5) endocrine – pituitary gland, thyroid gland, pancreas: communication, control (hormones control growth, metabolism, homeostasis)

6) cardiovascular (circulatory) – heart, blood, blood vessels: transport materials through body (oxygen, nutrients, carbon dioxide)

7) lymphatic – lymph nodes, lymph vessels (fight disease)

8) digestive – stomach, intestines, esophagus (break down nutrients for absorption)

9) respiratory – lungs, trachea, bronchi (gas exchange: oxygen and carbon dioxide)

10) urinary – kidneys, bladder, urethra (excrete nitrogenous waste)

11) reproductive – sex organs (male and female functions)

Organ Systems

Each system performs specific functions, but all organ systems depend on one another. For example, the digestive system breaks down the food we eat, but the circulatory system transports the nutrients to cells throughout the body for energy.

The Digestive System The human digestive system is responsible for the breakdown of food, the absorption of nutrients, and the elimination of waste. Ingested food passes through the digestive tract, or alimentary canal, in this sequence:

1. mouth (oral cavity) 2. pharynx (throat) 3. esophagus (food tube) 4. stomach – protein digestion begins here; hydrochloric acid has pH of 1 5. small intestine (duodenum, jejunum, ileum) – most digestion + absorption 6. large intestine (ascending colon, transverse colon, descending colon)

* The appendix is a vestigial structure with no apparent function in modern humans. 7. rectum 8. anus

Trace the path of a bolus (ball) of food through the digestive tract.

eliminating

Accessory organs aid in the process of digestion, but are not part of the alimentary canal. Food does not travel directly through them:

1. salivary glands – produce saliva to aid in carbohydrate digestion 2. liver – produces bile to aid in fat digestion; also stores glycogen (a

polysaccharide, or complex carbohydrate, containing glucose sugar units) 3. gallbladder – stores bile and releases it when needed 4. pancreas – secretes digestive juices; also produces hormones to maintain

sugar balance (insulin lowers blood sugar; glucagon raises blood sugar)

LIVER: consists of several lobes

GALLBLADDER: tiny greenish sac under the liver

PANCREAS: hides behind the stomach