Chapter 18 Nutrition and Metabolism

6 Major NutrientsWaterCarbohydratesFatsProteinsVitaminsMinerals

Essential vs. Nonessential

Appetite Control Regulated by hypothalamus (in

brain) Hormones:

• Insulin – stimulates adipose to put glucose into cells and store fat

• Leptin – decreases appetite• NeuropeptideY – increases

appetite, negative feedback loop based on ingested calories

• Ghrelin – increases appetite (gastric bypass surgery decreases this hormone)

http://research.archives.gov/description/5709999

1916 – a good read! I think the 4 food groups were milk stew, milk toast, milk

pudding, and milk soup.

1st use of food groups

1940s

Old food pyramid – 1990s

How can this be improved??

New – includes visual of serving sizes

Carbohydrates Primary energy source (4 Calories per gram) Used to make ribose and deoxyribose + breast

milk (lactose)

Monosaccharides – honey, fruit Disaccharide – lactose, sucrose

Polysaccharides –• meats (glycogen)• Plants (cellulose)

Lipids Triglycerides – most concentrated source

of energy (9 Calories per gram)

Used for phospholipids, cholesterol – hormones, myelin

Adipose tissue – pg 158

Liver uses fatty acids to make other kinds of lipids

Food vs. Bad Cholesterol

“Carriers” of

cholesterol

Cholesterol processing in liver and relation to cardiovascular disease and arterial

plaques

High levels of LDL and low levels of HDL increase risk of heart attacks.

HDL is believed to carry LDLs away from blood vessels and back to liver for processing.

Proteins Sources: meat, dairy, nuts, legumes (4

Cal/gram) Used for:

• Antibodies, enzymes, hemoglobin• Muscle (actin and myosin)• Collagen, keratin, elastin (connective

tissues)• Biologically complete vs. incomplete

proteins Areolar tissue – page 157

Reticular tissue – page 159

Vitamins “Vital Amines”

Destroyed by heat

Excess can be toxic

Antibiotics can lead to deficiencies

Vitamins

Fat soluble Water SolubleA CD BEK

Mainly from meat

Mainly from meat

Bacteria, problem

for babies, needed for

blood clotting

Bacteria, problem

for babies, needed for

blood clotting

Often serve as coenzymes

Beri-beri, vitamin B

Pellagra, vitamin B Glossitis, vitamin

B

Spina bifida, folic acid Scurvy, vitamin C

Xeropthalmia, Vitamin A

Rickets, Vitamin DGoiter, Iodine

Fluorosis, fluoride

Inorganic, ionized form

Ca, P, S, K, Mg, Na, Cl, Fe, I………..

Minerals