Nutrition Final

Nutrients

Nutrients

• Substances essential for health that the body cannot make or makes in quantities too small to support life

  • Primarily provide energy

  • Important for growth and development

  • Keep body functions running smoothly

Essential Nutrient

• specific biological function

• Absence from the diet leads to decline in biological function

• Adding missing substance back to the diet before permanent damage occurs restores normal biological function

Macronutrients

carbs, proteins, lipids, water

micronutrients

vitamins, minerals

Carbs

4kcal/g

Complex Carbs

Starch, Fiber

Simple Carbs

Sugar, readily usable

Lipids

9kcal/g

insoluble in water

Fats

lipids solid at room temp

Oils

lipids liquid at room temp

Triglycerides

3 fatty acids attached to glycerol backbone

Saturated Fats

solid at room temp

animal sources

raise blood cholesterol lead cardiovascular disease

unsaturated fats

liquid at room temp

plant sources

healthier than saturated

Essential Fatty Acids, Unsaturated fatty acids

Linoleic Acid

Alpha-linolenic acid

• structural cell wall

• blood pressure

• nerve transmissin

• found vegetable oils and fish

Trans Fatty acids

unsatured fats processed from cis form to trans form

deep-fried food, snacks

pose health risk

Proteins

4kcal/g

Vitamins

main functional component to enable chemical reactions to occur

helps release energy but does not provide energy

Water soluble vitamins

vitamin C and B-vitamins

excreted more readily

Fat soluble vitamins

vitamins A, D, E, K

more likely accumulate and cause toxicity

Minerals

inorganic substances (no carbon bound to hydrogen)

not destroyed by cooking

yield no energy

Major minerals

need in gram amounts daily

Trace minerals

needed <100 mg daily

Phytochemicals

physiologically active compounds found in plants that may provide health benefits

Zoochemicals

physiologically active compounds found in foods of animal origin that may provide health benefits

Claims about health

must be approved by FDA

• Claims about nutrient “great source of”

Claim about structure or function

does NOT have to be approved by FDA, but need to have evidence its true

%DV

based on standard 2000-calorie diet and allows for comparison of products, percentage of nutrient provided by standard serving of food in relation to approximate requirement for nutrient

Calorie

amount heat energy needed to raise the temp of 1 gram of water 1 degree celsius

Alchohol

7kcal/g

North American Diet

16% protein

50% carbs

33% fats

hunger vs appetite

physical need for food vs psychological desire to eat

undernutrition

nutrient intake does not meet needs

nutrient stores depleted

overnutrition

consumption of more nutrients than body needs

Assessing Nutritional Status

• Family history and self history

• Anthropometric assessment

• Biochemical assessment

• Clinical assessment

• Dietary assessment

• Environmental assessment

EAR

meet need of 50% people

DRI graph

AMDR (acceptable macronutrient distribution ranges)

Carb (45-65%)

Protein (10-35%)

Fat (20-35%)

Daily Values

compares amount nutrient in food with set of standards

Food security

access by all people at all times to enough food for an active, healthy lift

food insecurity

fewer servings of nutrient dense foods and consume poorer quality diets, linked with obesity

Household manage any level food security by:

skipping meals, reducing the size of meals, not eating when hungry

____ US below poverty guiltiness of _____for family of 4

12%, $25,750

Food desert

geographic areas where fresh, affordable, healthy food cannot be purchase easily

Government programs

• Supplemental Nutrition Assistance Program (SNAP)

• Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)

• National School Lunch Program

• School Breakfast Program

• Child and Adult Care Food Program

• Programs for seniors: Meals on Wheels, Senior Farmers’ Market Nutrition Programs, congregate meal programs

• Food distribution programs: food banks and pantries

Food waste

1/3 all food product lost

Food sustainability

ability to produce enough food to maintain the human population

Agrobiodiversity

diversifying species to increase variety in food supply leading to higher quality diet

GMO Pros

1. improve quality food

2. easier to grow

3. increase food yields

4. shipped to remote areas

5. herbicide use is less

6. GMO foods meet same requirements as all other foods

GMO cons

1. increase food related allergies

2. trigger allergies from alternative foods

3. antibiotic resistance

4. GMOs connected cancer

5. monopolies

6. herbicide resistance happens naturally w/o genetic engineering

7. independent research not allowed

Food irradiation

use radiation to extend shelf life food and control growth insects or pathogens

Danger zone bacteria in food

41 F - 135 F

Food safety procedures

Clean, separate, chill, cook

gastrointestinal tract organs

• Mouth

• Esophagus

• Stomach

• Smallintestine

• Large intestine

– Rectum

– Anus

Mechanical Digestion

• Begins in the mouth

– Teeth masticate

– Food bolus

• Esophagus

– Peristalsis

• Stomach

–  Smooth muscle contractions

–  Storage

–  Chyme

• Smallintestine

– Segmentation

Chemical Digestion

• Enzymes

• Hormones

• Mouth

– Salivary glands

-- Saliva

-- Amylase

-- Lipase

• Stomach

– Gastric juices

-- Acid

-- Proteases

-- Lipase

• Liver

– Bile is synthesized

• Small Intestine

- CCK

• Gallbladder

– Bile is released

• Pancreas

– Pancreatic juices

-- Bicarbonate

-- Amylase

-- Proteases

-- Lipase

Small Intestine

Three regions

– Duodenum

• Proximal

– Jejunum

• Middle

– Ileum

• Distal• Longest

Brush border

– Villi

– Microvilli

• Surface area for absorption

Large Intestine

Three regions

• Cecum

• Colon

• Bacterial flora

• Rectum

• No villi

• Mucus

Probiotic

beneficial bacteria

Prebiotics

• Food for the beneficial bacteria

• Chicory, whole-grain rye, oats, wheat , barley, leeks, onions, and garlic

Diverticulitis

pouches form in wall of digestive tract

Gastritis

roup of conditions that cause inflammation of the stomach lining. It can be caused due to alcoholic abuse, infection or underlying conditions

Ulcer

when inflammation becomes bad enough, the acid in your stomach brakes through the stomach lining and creates a hole or a sore. Related to diet, but also related to high levels of stress and anxiety

Celiac Disease

• Completely treatable by avoiding gluten

  – Protein found in wheat, rye, and barley

• Can lead to damage of microvilli

  – Can led to malabsorption and malnutrition

Monosaccharides

Glucose, fructose, galactose

disaccharides

maltose: 2 glucose

sucrose: glucose, fructose,

lactose: glucose, galactose

Complex carbs

starch, fiber, glycogen

Glycogen

Stored glucose in the body

– Liver• Broken down to provide glucose in the blood

– Muscle• Broken down to provide energy to do work

Whole grains

Contain the endosperm, germ, and bran in original proportions

Refined Grains

Stripped of the germ and bran, leaving only the endosperm

Enriched grains

Some nutrients lost in processing are added back

Amylase

• Mouth

– Breaks starch into smaller links of glucose

• Small intestine

– Continue digestion of starch into maltose and glucose

Small intestinal cells

• Maltase

– Hydrolyzes maltose to produce two glucose monosaccharides

• Sucrase

– Hydrolyzes sucrose to produce one glucose and one fructose monosaccharide

• Lactase

– Hydrolyzes lactose to produce one glucose and one galactose monosaccharide

Monosaccharides

______ are absorbed by small intestine, and then transported to the blood

lactose intolerance

• Low lactase activity

• Lactose maldigestion

– Diarrhea, Gas, cramps, abdominal pain

• Treatment

– Decrease dairy intake, Lactase pills, Calcium-rich foods

Normal fasting blood glucose levels:

• 70-100 mg/dl

Hyperglycemia, Hypoglycemia

• Above 126 mg/dl is classified as diabetes _____

• Hunger• Thirst• Frequent urination • Weight loss

• Below 50 mg/dl is classified as _____

• Hunger • Shakiness • Irritability• Weakness • Headache

liver

• ____ determines amount of glucose that is needed to enter the bloodstream after a meal

  – Stored as glycogen for later use

Pancreas secretes:

insulin, glucagon

insulin

Released after eating, when blood glucose levels are high,

• Promotes: Glucose uptake by cells, Use of glucose as energy, Storage of excess glucose as glycogen

Glucagon

Released if no dietary carbohydrates are present, blood glucose levels have fallen

Promotes: Breakdown of glycogen, Gluconeogenesis

Refined sugars are added to:

– Add flavor

– Increase energy density

– Decrease nutrient density

– Contribute to obesity

nutritive sweeteners

– Provide calories, but fewer than sugars – Have reduced absorption– Include sugar alcohols (polyols)

non-nutritive sweeteners

calorie free

Soluble fibers

– Softens stool and decreases constipation

– Decreases hemorrhoids and diverticular disease

Soluble fiber

– Slows stomach emptying

–  Slows digestion and absorption

–  Reduces the risk of coronary artery disease

Dietary fibers

• Nondigestible carbohydrates

• These fibers pass through the small intestine into the large intestine, where they may be partially or completely fermented by gut bacteria.

Functional Fibers

• Isolated or purified carbohydrates that are nondigestible

• Absorbed in the small intestine, and have beneficial physiological effects in humans

Categories of lipids

fatty acids, triglycerides, sterols, phospholipids

Saturated fatty acids

fully hydrogenated, solid room temp

monounsaturated fatty acids

one double bond or point of unsaturation in carbon chain

polyunsaturated fatty acids

more than one point of unsaturation or more than one double bond

Triglycerides

3 carbon glycerol molecule with 3 fatty acids attached, storage form of fat

Phospholipids

3 carbon glycerol molecule with 2 fatty acids and a phosphate group on 3rd carbon

Sterols

complex lipid 4 carbon rings and hydrocarbon side chain

cholesterol most common sterol

Lipid digestion

• salivary Glands

• stomach

• liver

  • produces bile

• gallbladder

  • stores bile

• pancreas

  • release enzymes

• small intestine

  • adds bile, enzymes and emulsifies lipids

Chylomicrons

lipoproteins made in intestinal cells or enterocytes

transport fat from intestine to body

very low density lipoprotein (VLDL)

made in liver

transports fat from liver to body

low density lipoprotein (LDL)

made in liver

transports cholesterol from liver to cells of body

“bad cholesterol”

high density lipoprotein (HDL)

collects fat and cholesterol from body to transport back to liver

“good cholesterol”