Macronutrients Flashcards
Energy
capacity of a physical system to do work
energy in kilocalories and joules
kilocalories: 1 kg of H2O, 1 C
Joule: 1kg of a substance, 1 meter using a force of 1 newton (1kcal = 4.184 KJ)
Energy content of carbohydrate
4 kcal
Energy content of protein
4 kcal
Energy of lipid
9 kcal
Energy of alcohol
7 kcal
What are the macronutrients?
carbs
fat
protein
What are the main components of energy expenditure?
REE (resting energy expenditure)
TEF (thermic effect of food)
AEE (activity related energy expenditure)
Resting energy expenditure
accounts for more than 50-70% of total energy expenditure
- related to lean body mass
Thermic effect of food
accounts for about 10% of total energy expenditure
Activity related energy expenditure
represents 15-30% of total daily energy expenditure
- dependent on physical activity
What factors should be considered when determining energy needs?
- age
- activity
- gender
- body size/composition
- climate
- pregnancy/lactation
How do you measure resting metabolic rate?
indirect calorimetry or use formula
What is RMR influenced by?
lean body mass growth fever disease cold
What nutrition concerns should you be aware when selecting food for a diabetic?
carbohydrate intake amounts
What nutrition concerns should you be aware when selecting food for a vegetarian?
Adequate protein intake (and Vitamin B12)
What are the 3 monosaccharide simple sugars?
glucose
fructose
galactose
Sucrose contains which 2 simple sugars?
glucose, fructose
Lactose contains which 2 simple sugars?
glucose, galactose
Maltose contains which 2 simple sugars
glucose AND glucose
Where does carbohydrate digestion begin?
in mouth (enzymes)
The majority of carbohydrate absorption occurs in the _____?
jejunum
Roughly how much carbohydrate reserve is stored in the body? And where is it located?
1/2 day supply
in liver and muscle
What is the most readily available source of dietary energy?
carbohydrate
Carbohydrate function
- protein sparing (prevents use of proteins for energy)
- anti-ketogenic
- energy
RDI of carbohydrates
45-65% total caloric intake
Insoluble fiber
- doesn’t dissolve in body
- adds bulk and softness to stool
Soluble fiber
- dissolves in body into gummy/viscous substance
- binds to fatty substances and promotes their secretion as waste
Which fiber helps to lower blood cholesterol levels?
soluble
Group of fibers in insoluble fibers
cellulose
hemicellulose
lignin
found in plant walls
Group of fibers in soluble fibers
gums
mucilages
pectins
Insoluble fiber food sources
Bran cereal
celery
apple skin
Soluble fiber food sources
Oat bran cereal or oatmeal
banana
pear
RDI for fiber to increase health benefits
19 - 38g/day
What is important about increasing fiber?
- increase slowly!
- about 5g every week to goal
- Match with adequate water
Side effects of high fiber diet
- too much too quickly: bloating, constipation
Common food sources of fiber
fruits, veggies, whole grains
How many grams of carbohydrates should be consumed to avoid using protein as energy? What is it called?
min 130g/day
protein sparing
Complete proteins
all the AA in body needed to digest
- meat, poultry, fish, eggs, milk, cheese, soy
incomplete proteins
Missing 1 or more AA to digest
- legumes, seeds, nuts, grain, veggies
Where does protein digestion begin?
in stomach
T/F essential proteins are made in the body
False; essential come from food and NOT synthesized in body
Non-essential proteins are synthesized in body
Why is protein an important nutrient to consume?
supplies AA for growth and maintenance of body tissues
What is the element that is the main component of proteins?
Nitrogen
Where are most AA absorbed?
duodenum
RDI of proteins
10-35% of total caloric intake
What is the most abundant form of lipids?
FA phospholipids
Saturated FA
- single C=C
- line up well
- solid at RT
- have all the H they can hold
- meat, poultry, butter, whole milk fat, palm oil
Unsaturated FA
- one or more double bonds
- don’t line up well
- liquid at RT
What are the essential FA?
- linoleic acid (Omega 6)
- linolenic acid (Omega 3)
Purpose of essential FA
- precursors of hormone like compounds
- components of nerve tissue and the retina
- body cannot manufacture all or enough
- absence results in disease
Where does lipid digestion start?
mouth (enzymes)
What are the functions of fat within the body?
- energy
- thermal insulation
- vital organ protection
- nerve impulse transmission (myelin)
- tissue structure
- cell metabolism
- essential precursor for all steroid hormones
- carries fat soluble vitamines
- enhances food flavor and texture
RDI of lipids
20-35% of total calories
Monounsaturated lipids
- FA missing one 1 H pair
- liquid at RT
- canola, olive, peanut oils
Polyunsaturated lipids
- FA missing 2 H pairs
- liquid at RT
- corn, safflower, soybean, sunflower oils
Omega 3 FA food sources
seafood almonds walnuts flaxseeds soybeans canola and olive oil
Omega 6 FA food sources
safflower grapeseed sunflower poppyseed palm oil
For healthy weight loss, how should many calories do you need to reduce?
start with 500 calorie reduction
RDI for macronutrients
CHO: 45-60%
Fats: 20-35%
Protein: 10-35%
What nutrition concerns should you be aware when selecting food for someone with heart disease?
- avoid saturated fat intake
- choose lean meats and dairy options
- increase Omega 3 intake
- increase fiber
Importance of water
- regulates body processes
- carries nutrients and other body chemicals to cells
- carries waste products away
- help regulate BT
Total body water of body weight, intracellular fluid and extracellular fluid
60% body weight
2/3 intracellular fluid
1/3 extracellular fluid
What is the average amount of water an adult loses a day?
10 cups daily
Volume depletion of water
un-replaced losses from prolonged sweating, vomiting, diarrhea, burn injury
Volume excess of water
diseases like kidney or heart failure prevent normal excretion of Na and H2O
Daily requirement of water
8-12 cups daily
What’s the best indicator on water deficiency?
color of urine
RDI of sodium
1000mg - 1500mg/day
Food sources of sodium
processed foods
smoked meats
condiments
table salt
RDI of potassium
3000mg - 4700 mg/day
Food sources of potassium
veggies, fruits
salt substitute
What is sodium regulated by?
ADH
What is potassium regulated by?
aldosterone
Potassium deficiency
hypokalemia (muscle weakness, cardiac, respiratory)
Potassium excess
hyperkalemia (fibrillation and death)
What is chloride regulated by?
aldosterone
RDI of chloride
1500mg - 2300mg/day
Food sources of chloride
salt and salty foods
Benefits of Omega 3 intake
decrease CVD, inflammatory reactions and tumor growth
Benefits of Omega 6 intake
structural component of membrane lipids, involved with cell signaling and require for normal skin function
Which FA increases HDL?
monosaturated
Which FA are “heart neutral”?
polyunsaturated