NUTR 201: Final Exam SDSU

Nutrition

ingestion, digestion, absorption, metabolism, and storage

Food Science

food analysis, sensory analysis, food chemistry, and product development and testing

Classes of Nutrients (6)

carbs, fats, proteins, vitamins, minerals, and water

Phytonutrients

nutrients in PLANT FOODS

Zoonutrients

nutrients in ANIMAL FOODS

Function of nutrients

- Provide energy for metabolism

- Build and repair body tissues

- Help regulate body processes

calorie

energy required to increase the temperature of one gram of water by 1*C

Calorie

dietary calorie

1 Calorie = ___ kilocalorie = ___ calories

1 kilocalorie; 1000 calories

Bomb calorimeter

an instrument that measures the heat energy released when foods are burned, thus providing an estimate of the potential energy of the foods

kcal/g for carb, fat, protein, and alcohol

carb - 4kcal/g

fat - 9kcal/g

protein - 4kcal/g

alcohol - 7 kcal/g

Macronutrients

Fat, Protein, and Carbs

- required in large amounts

Micronutrients

vitamins and minerals

- required in small amounts

Nonessential nutrients

can be made by body

Essential nutrients

cannot be made by body

Top 10 Leading Causes of Death in United States

1. heart disease (28%)

2. cancer

3. stroke

4. chronic lung disease

5. accidents

6. diabetes mellitus

7. pneumonia and influenza

8. alzheimer's disease

9. kidney disease

10. blood infections

Major Diet Related Diseases

1. coronary heart disease

2. stroke

3. diabetes mellitus

4. hypertension

5. obesity

6. certain forms of cancer

7. osteoporosis

8. liver disease

9. mental health

4 Principles for Avoiding Malnutrition

1. variety

2. balance

3. moderation

4. nutrient density

Dietary Guildlines for Americans

1. healthy eating pattern across the lifespan

2. focus on variety, nutrient density, and amount

3. limit calories from added sugar, saturated fats, and reduced sodium

4. shift to healthier food and beverage choices

5. support healthy eating patterns for all

Consume less than ____% of calories per day from added sugars.

10%

Consume less than ____% of calories per day from saturated fats.

10%

Consume less than ______mg of sodium per day.

2300mg

Alcohol: Only ___ drink(s) per day for women.

1

Alcohol: Only ___ drink(s) per day for men.

2

Adults should at least spend ______ minutes of moderate intensity physical activity each day.

150 minutes

Adults should spend _____ days or more of muscle strengthening exercises per week.

2 or more days

Children (6-17 y/o) should spend at least ____ minutes doing physical activity per day.

60 minutes

Leading Reasons for Food Selection in US

flavor and cost

RDA

Recommended

Daily Allowance

- for nutritional needs of practically all healthy persons

AI

Adequate Intake

- used when evidence isn't considered good enough to call it an RDA

EAR

Estimated Average Requirement

- meet needs of the average person, can help establish the RDA (is 2 standard deviations above)

UL

Tolerable Upper Intake Level

- the level we should not exceed

EER

Estimated Energy Requirement

- takes sex, age, weight, height, and physical activity level into account

AMDR

Acceptable Macronutrient Distribution Range

- carbs = 45-65%

- fat = 20-35%

- protein = 10-35%

Nutrition Label Requirements

- list of Ingredients

- serving size

- servings per container

- amount per serving (total calories, calories from fat, total fat, saturated fat, trans fat, sodium, cholesterol, total carbs, dietary fiber, sugars, protein, Vitamin A & C, calcium, and iron)

Changes to new food labels

- adding added sugars

- removing Vitamin A & C

- adding Vitamin D & potassium

- removing calories from fat

Voluntary on Nutrition Labels

- kcal from sat/polyunsat/monounsat fat

- soluble fiber

- insoluble fiber

- sugar alcohols

- other carbs and micronutrients

- Daily Value

- Reference Daily Intakes

- ingredients that may cause reactions in food sensitive consumers

Food Label Claims by FDA

- health

- nutrient content

- structure function

"Low calorie"

40 calories or fewer per serving

"Reduced calorie"

at least 25% lower in calories than regular food

"Calorie free"

fewer than 5 calories per serving

"Trans fat free"

less than 0.5 g trans fat and less than 0.5 g of saturated fat per serving

Pesticides

1. avoid direct contact

2. most fruits and vegetable have no pesticides or negligible amounts within safe limits for adults

3. fish from contaminated waters may contain high levels of pesticides

"100% organic"

- made with 100% organic ingredients

- USDA logo can be used

"Organic"

- minimum 95% ingredients are organic

- may include USDA logo

"Made with organic ingredients"

- 70%-94% is organic

- cannot use USDA label

ingredient panel only*

- less 70% organic

- organic can only be used on ingredient panel

How to eat food on a budget?

1. get unpackaged whole food

2. sales, but not unhealthy choices

3. deals and groupons online before you go

4. farmers market

5. buy seasonal and local foods

6. meal prep

7. choose the right supermarket

Quackery

1. big business

2. sales people use questionable scientific info

3. expected benefits are trivial compared to extravagant claims (no legitimate basis)

Where can you find accurate information regarding nutrition?

- books on nutrition (textbooks)

- scientific journals (important not to overinterpret)

- governmental agencies (USDHHS, USDA, FDA, etc)

- scientific organizations (AND, ASN, etc)

- nutrition professionals

Processed food

1. prevents spoilage

2. some food enriched or fortified

3. some nutrients may be lost

4. problem is the excessive use of highly refined products

Purpose of additives in food

1. flavor

2. enhanced color

3. improve texture

4. preserve the food

- must be generally recognized as safe (GRAS) to earn FDA approval

Digestion

breaking down macronutrients to yield nutrients ready for absorption

Absorption

movement of nutrients from intestinal tract to the circulation

Upper GI Tract

- oral cavity

- esophagus (LES)

- stomach (pyloric sphincter)

gastroesophageal sphincter

- separates the esophagus from the stomach

- closes to prevent the stomach contents from re-entering the esophagus

Lower GI

- small intestine (duodenum, jejunum, ileum)

- large intestine/colon (cecum, ascending, transverse, descending, sigmoid)

- rectum

Accessory Organs

liver, gallbladder, pancreas

Role of the Stomach

- mixing

- secretion of gastric juices:

1. HCL= protein denaturation and kills bacteria

2. pepsin

3. mucus for protection

4. intrinsic factor for vitamin B12 absorption)

- production of hormones

Secretions of pancreas

- enter at duodenum

- biocarbonate = increases pH

- enzymes = breakdown protein, fats, and carbs

role of small intestine

Secretions of gallbladder

- enter duodenum

- bile acids = made in liver and allow fat digestion and absorption

role of small intestine

Role of the Large intestine

- water absorption

- electrolyte absorption

- bacterial action (fermentation, some vitamin production, probiotics v. prebiotics)

Probiotics

beneficial live bacteria found in certain foods or supplements

Prebiotics

special form of dietary fiber that acts as a fertilizer for the good bacteria in your gut

The rate at which food leaves the stomach is influenced by...?

- volume

- consistency

- composition of chyme

Amount of time between ingestion of food and its elimination?

24-72 hours

- fiber moves faster

Factors affecting transit time of food out of the body

- composition of diet

- illness

- certain medications

- physical activity

- stress/emotions

Major mechanisms of Absorption

- diffusion

- facilitated diffusion

- active transport

Energy Metabolism

chemical reaction involved in breakdown, synthesis, and transformation of energy yield nutrients

Metabolic Pathways

a series of enzymatic reactions that converts one biological material to another

Catabolic

breaking down molecules

Anabolism

synthesis of molecules

Enzyme Catalyzed Reactions

- reversible

- enzymes

- many types

- cofactors / coenzymes often assist enzymes

Enzymes

catalysts that speed of chemical reactions

ATP

Adenosine Triphosphate

- provides energy needed for biosynthesis, muscle contractions, active transport

Electron Transport Chain (ETC)

series of chemical reactions that transfer electrons and 4 hydrogen ions from reducing agents along protein complexes in the inner mitochondrial membrane producing ATP

Glycogenolysis

start with glycogen,

end with individual glucose molecules

Glycolysis

breakdown of glucose to pyruvate or lactate

Kreb Cycle

Tricarboxylic acid cycle (TCA)

- major pathway used during aerobic conditions

- forms guanosine triphosphate (GTP) and reduced coenzymes (NADH + H+ and FADH2)

Fat Catabolism

breakdown of triglyceride molecules into glycerol and fatty acids when available energy sources are low

- lipolysis is followed by beta-oxidation

Lipolysis

the breakdown of fats and other lipids by hydrolysis to release fatty acids

Beta Oxidation

breakdown of fatty acids

Protein Catabolism

- first broken down to amino acids

- supplies <10% of daily ATP

- transamination

- deamination

- krebs cycle

- election transport chain

Transamination

transfer of amino group from an amino acid to alpha ketoacid

Deamination

removal of amino group from an amino acid to produce alpha ketoacid

Anabolic Pathways

- gluconeogenesis

- glycogenesis

- lipogensis

- ketogensis

- protein synthesis

Gluconeogenesis

formation of glucose from noncarbohydrate sources

Glycogenesis

formation of glycogen from glucose

Lipogenesis

excess glucose or amino acids make triglyceride (fatty acids or lipids)

Ketogenesis

- usually occurs at higher rates during starvation, consumption of a low carbohydrate diet, or during uncontrolled diabetes

- accumulation of acetyl coA results in ketones

Protein synthesis

- transcription: DNA --> RNA

- translation: RNA --> protein

Where do carbs come from?

photosynthesis

Monosaccharides

glucose, galactose, fructose

- ready for absorption from the gut without further digestion

Disaccharides

lactose = galactose and glucose

maltose = glucose and glucose

sucrose = fructose and glucose

Complex Carbs (polysaccharides)

starch - storage form in plants

glycogen - storage form in humans

non-digestible fiber

Insoluble Fiber

cellulose, hemicellulose, lignin

- wheat and other plant foods

Soluble Fiber

pectins, gums, beta-glucans

- fruits, most grains, beans

What are primary sources of digestible carbohydrates?

grains, fruit, and vegetable

- other sources: dairy, protein, and sweets

Dietary Goals of Carbs

1. AMDR: 45-65% calories

2. RDA: 130g/d & an

upper limit for sugar of 10%

3. Daily Reference Value is 300g

4. Fiber: RDA 25g women and 38g men

Absorption of Carbs

- almost all monosaccharides

- glucose and galactose by active transport

- fructose by facilitated diffusion

- fructose and galactose are converted to glucose in liver and used or sent into blood stream

- glucose metabolized by liver or sent through bloodstream to other tissue/cell (most important physiologically and RBC love)