Lecture 15 Macronutrients Metabolism Overview I+II

Question 1

What are macronutrients

Answer 1

Class of chemical compounds that humans consume in large quantities and provide the majority of our energy ( carbs,lipids,protein)

Macronutrients that do not provide energy (water, fiber)

Question 2

Balancing 3 macronutrients percentages

Answer 2

AMDR- Carbs 45-65%
AMDR- Fat 20-35%
AMDR- Protein 10-35%

AMDR - acceptable macronutrient distribution range

Question 3

What are carbohydrates

Answer 3

One of three macronutrients

Important source of energy for all cells

Only energy source for red blood cells

Composed of carbon, hydrogen, oxygen

Glucose most abundant

Question 4

Monosaccharides

Disaccharides

Answer 4

Monosaccharide: One molecule ( Glucose, fructose, and galactose

Disaccharides: two molecule (lactose, maltose, sucrose)

Question 5

Galactose+ glucose =

Answer 5

Lactose

Question 6

Glucose+ glucose =

Answer 6

Maltose

Question 7

Glucose + Fructose =

Answer 7

Sucrose

Question 8

What are complex carbohydrates

Answer 8

Oligosaccharides contains 3 to 10 monosaccharides

Startch, glycogen, most fibers

Question 9

Startch, glycogen, fiber functions

Answer 9

Startch = storage form of glucose in plants ; food sources include grains, legumes and tubers

Glycogen = storage form of glucose in animals ; stored in liver and muscles

Fiber = forms the support structures of leaves, stems and plants

Question 10

Fiber

Digestion and absorption
Sources

Answer 10

Most fibers are not digested and absorbed by our bodies

Soluble fibres can be digested by bacteria in our colon

Source: whole grains, vegetables, nuts and seeds, fruits.

Question 11

Importance of carbohydrates in the diet

Answer 11

Carbohydrates spare protein and prevent ketoacidosis

Fiber helps us stay healthy - promote bowel health, reduces risk of diverticulosis, reduce risk of colon cancer

Question 12

How much carbohydrate should we consume in a day

Answer 12

130grams a day

Range o 45 to 65% of daily calories

Question 13

Consuming to much carbohydrates

Answer 13

High in simple sugars can cause tooth decay, increase LDL, decrease HDL, contribute to obesity

Fructose may increase hepatic de novo lipogenesis, may increase visceral adiposity,

Question 14

Too little carbohydrates

Intake for women and men, where to get fiber from

Answer 14

14g of fiber for every 1000 kcal per day( 25g/day for women and 38g/day for men)

Best to get fiber from food

Question 15

What is enriched and fortified food

Answer 15

Enriched : nutrients that were lost during processing have been added back so the food meets a specific standard

Fortified: have nutrients added that did not originally exist in the food

Question 16

Anatomy of grain

Answer 16

Bran - rich in fibre and vitamins

Endosperm = rich in carbs and protein

Germ - rich in unsaturated fats and vitamins

Question 17

Nutritive sweeteners vs non nutritive ( alternative) sweeteners

Answer 17

Nutritive sweeteners - sucrose, fructose, honey, brown sugar, contains 4 kcal per gram. Slow absorbing sugar alcohols

Non nutritive (Alternatives) sweeteners - provide little or no energy, safe for adults, children and people with diabetes

Question 18

What about alternative sweeteners

Acceptable daily intake

Answer 18

50mg/kg body weight for aspartame
5mg/kg body weight for sucralose

Question 19

What are lipids

Answer 19

Diverse group of molecules that are insoluble in water

Question 20

What are the three types of lipids found in foods and in body cells and tissues

Answer 20

Triglycerides
Phospholipids
Sterols

Question 21

What are triglycerides

Answer 21

Three fatty acid molecules
One glycerol molecule

Question 22

Fatty acids are classified by :

Answer 22

Carbon chain length - How many C
Saturation Level - how many double bonds
Shape - straight and rigid or bent and kinked

Question 23

Triglyceride carbon chain length

Answer 23

Short - (<6), medium - (6,12), or long chain FAs (14+)

Carboxyl end (COOH): alpha-carbon (Alpha-first)

Methyl end (CH3): omega carbon

Determines method of lipid digestion, absorption, metabolism and use

Question 24

Saturation of triglyceride

Answer 24

Saturated fatty acids have hydrogen atoms surrounding every carbon in the chain

Monounsaturated fatty acids lack two hydrogen atoms

Polyunsaturated fatty acids (PUFA) have more than one double bond

Question 25

Triglyceride shape

Answer 25

Saturated fatty acids pack tightly together and are solid at room temp Unsaturated fatty acids do not pack tightly together and are more often liquid at room temp Hydrogen atoms at the unsaturated part can be arranged in different positions Cis: same side of carbon chain Trans: opposite sides of the chain

Question 26

Triglyceride hydrogenation

Answer 26

Hydrogenation: hydrogen atoms are added to unsaturated fatty acids Create trans fatty acids Reduce oxidation; resist rancidity

Question 27

Triglyceride fatty acids (EFAs)

Answer 27

Essential fatty acids - cannot be made by or body and must be obtained in the diet - linoleum acids ( omega 6 fatty acids), found in vegetable and nut oils - alpha-linolenic acid ( Omega-3fatty acid), found in vegetables, soy, flaxseeds, and flaxseed oil, soybeans and soybean oil

Question 28

Phospholipids consist of the following

Answer 28

Glycerol backbone, two fatty acids, phosphate Hydrophobic end, which is their lipid “tail” and a hydrophilic end, which is their phosphate “head” Transport substances in and out of the cell

Question 29

Phospholipids in the liver are called _____ (combined with bile salts and electrolytes)

Answer 29

Lecithins AIDS in digestion of fat

Question 30

Sterols Found in both Contain multiple Foods….

Answer 30

Found in both plant and animal foods and produced in body Contain multiple rings of carbon atoms Primarily found in fatty part of animal products Cholesterol (Exogenous vs endogenous)

Question 31

The Importance of fats in the diet

Answer 31

Fats are a major fuel source at rest: 9kcal/g, 30-70% of our daily energy, primary fuel source for the heart Important for energy storage Essential fatty acids Fat-soluble vitamins

Question 32

How much fat is acceptable

Answer 32

Acceptable macronutrient distribution range for fat : 20-35% of calories Active people may need more energy from carbs and can reduce their fat intake to 20-25% of total calories Minimize saturated and trans fatty acid intake

Question 33

Ratio of linoleic: alpha-linolenic acid

Answer 33

5:1 to 10:1 ratio of linoleic: alpha -Linolenic acid

Question 34

What are proteins

Answer 34

Large, complex molecules found in cells of all living things - synthesis controlled by genetic material (DNA) -contain carbon, hydrogen, oxygen, nitrogen -made from a combination of amino acids

Question 35

Amino acids are connected by ….

Answer 35

Peptide bonds, di-tri-oligo-poly-peptides

Question 36

Amino acids Essential amino acids Nonessential amino acids Transamination

Answer 36

Nine essential amino acids: - cannot be produced in sufficient quantities to meet physiological needs - must be obtained from food Non essential amino acids - can be synthesized in sufficient quantities Transamination - transfer amine group from an essential amino acid to a different acid group and R group - used to make nonessential amino acid

Question 37

What is phenylketonuria (PKU)

Answer 37

Condition where the body cannot metabolize phenylalanine and it can build up toxic levels if consumed in significant quantities in diet

Question 38

How are proteins made? Protein turnover

Answer 38

Existing proteins are degraded to provide the building blocks blocks for new proteins Amino acids pool includes amino acids from food and cellular breakdown

Question 39

Dietary protein Maximal effective protein dose in young health individuals is?? What are BCAA

Answer 39

20g Branched chain amino acids may be able to enhance muscle protein synthesis by activating mTOR

Question 40

What are some complementary food combinations

Answer 40

Rice and lentils Peanut butter and bread Tofu and broccoli Sesame seeds with mixed bean salad

Question 41

Functions of protein in the body

Answer 41

Cell growth, repair, maintenance Enzymes and hormones Fluid and electrolyte balance Acid-base balance Immune system Energy source Nutrien transport and storage Neurotransmitter synthesis

Question 42

Positive nitrogen balance Negative nitrogen balance In nitrogen balance

Answer 42

+ = body is retaining or adding protein: growth pregnancy or recovery from illness or a protein deficiency - = body is losing protein : starvation of very low energy diets, severe illness, infections, high fever, burns In nitrogen balance

Question 43

How much protein should you consume a day

Answer 43

0.8g per kg body weight per day ADMR for energy from protein is 10-35%

Question 44

What are some adverse effects of to much protein

Answer 44

Greater than 2g/kg body weight Increase bone loss Increase kidney disease in people who may be more suspceptible May Linked to increased risk of CHD

Question 45

What are some benefits to vegetarians diet

Answer 45

Reduced risk for obesity/type 2 diabetes Lower Bp Reduce risk of heart disease Fewer digestive problems Reduced risk of some cancers

Question 46

Vegetarian diets cons

Answer 46

Can be low in some nutrients Special attention to vitamins D, B12, Riboflavin, zinc and iron (vegans)