What are the 6 classes of nutrients?
proteins, fats, carbs, vitamins, minerals and water
What are the macronutrients?
proteins, carbs and fats
Which nutrient is the most energy dense?
fats
Which nutrients are organic?
proteins, carbs, fats and vitamins
What are the steps of the scientific method?
observation, question, hypothesis, experiment/design, conclusion
What are the epidemiological studies?
Cross-sectional, Case-control and cohort studies
What are the experimental studies?
Animal studies, in vitro studies and clinical trials
Cross-sectional studies
Research study observed at one set point
Case-control Study
Two groups that visualize changes usually in accordance with disease and a control group over time
Cohort studies
Examines a common group at defined intervals over time
What is DRI?
Dietary Reference Intakes
What is EAR?
Estimated Average Requirements
What is AI?
Adequate Intake
What is RDA?
Recommended Daily Allowance
What is UL?
Upper intake levels
Primary Nutrient Deficiency
Caused by inadequate diet
Secondary Nutrient Deficiency
Caused by other problems inside the body
How many cal/gram of carbs?
4 cal/gram
How many cal/gram of protein?
4 cal/gram
How many cal/gram of Fats?
9 cal/gram
How many cal/gram of alcohol?
7 cal/gram
Digestion
breaking down foods into nutrients in preparation for absorption
Absorption
The uptake of nutrients by cells of the small intestine for transport into either the blood or the lymph
What is the Cephalic phase?
Digestion begins here, when we think, smell, see or taste food our stomach begins to secrete gastric acids
What are the parts of the small intestine?
duodenum, jejunum and ileum
What organs are involved in digestion but not a part of GI tract?
pancreas, liver and gallbladder
Why might a fast-paced life affect digestion?
May not feel hunger right away as the cephalic phase takes time and stomach may not be able to prepare for food
What is bolus?
food that moves into the stomach
What is chyme?
Semiliquid mass that leaves stomach
What is bile?
emulsifier bringing fats into suspension with water
Where is bile made/stored?
made by the liver and stored in the gallbladder
What is bile needed for?
Digestion of fats
How does the small intestine absorb nutrients efficiently?
The small villi and microvilli increase surface area
What is the purpose of GI mucus?
Makes it so everything moves effectively
Simple Carbohydrates
Mono- and Disaccharides
Complex Carbs
Oligo- and Polysaccharides
What are the 3 monosaccharides
glucose, galactose and fructose
glucose
most abundant
fructose
found mostly in fruits
galactose
component of lactose, mammary glands
Sucrose is made of
glucose and fructose
Lactose is made of
galactose and glucose
What is lactose intolerance?
The lack of the lactase enzyme that breaks down lactose molecules in order for breakdown into monosaccharides
What are symptoms of lactose intolerance, explain?
Diarrhea is common because the larger sugar molecule pulls in water as it travels through digestive track
What is an oligosaccharide and what are they needed for?
They are carbs with 3-10 sugar units and needed for prebiotics
Starches
larger chains of sugars that take longer to break down and feel fuller
Glycogen
sugars stored into muscles
Soluble Fibers
slow gastric emptying, full feeling
Insoluble Fibers
provides bulk, better for constipation
Negative health outcomes from excess refined sugar
diabetes, insulin resistance and dental caries
Examples of Lipids
oils, butter, wax and sterols
Major functions of lipids
Storage, energy source, structure and communication
Building blocks of lipids
glycerol and fatty acids
Saturated fats
single bonded, solid at room temp
Unsaturated Fats
Double bonded, liquid at room temp
What are the essential fatty acids?
Omega 3 and 6
What are types of Omega 3 fatty acids?
ALA, EPA and DHA
What are good sources of Omega 3 fatty acids
ALA- chia seeds, EPA/DHA- fish
What is trans fat?
change from unsaturated to saturated form that is modified by scientists
Health risks of trans fat
Increases cholesterol, increases bad cholesterol and decreases good cholesterol
Main functions of cholesterol
Cell membranes, precursor to vitamin D and steroid hormones and needed for bile acid
Key steps of lipid digestion and absorption
Gastric lipase in stomach, bile in small intestine, absorbed through lymph system
How is fat stored in animals
stored as glycogen in the muscles
What are the building blocks of proteins?
amino acids
What is the name of bond between amino acids
peptide bond
primary structure of protein
chemical bonds only
secondary structure of proteins
electrical attractions
Tertiary structure of proteins
hydrophilic and hydrophobic
Quaternary structure
two or more polypeptides
Which populations need extra protein?
pregnant and lactating women, athletes
Functions of Proteins
hormones, neurotransmitters, enzymes
extreme protein deficiency
underweight, muscle wasting, poor growth and Kwahinorkor
What is metabolism?
all the chemical reactions in the body
What is ATP?
adenosine triphosphate, bodies energy
Glycolysis
cycle that converts glucose to pyruvate
TCA cycle, Kreb's cycle
cycle that converts acetyl coA to ATP
What happens with no oxygen when energy is needed?
anaerobic glycolysis can keep making small amounts of ATP by recycling itself
What is fatty acid oxidation?
The process of breaking apart fatty acids and making them into acetyl CoA
How can amino acids be used for energy?
converted to either pyruvate, acetyl CoA or they are able to simply enter TCA cycle as is
What are the products of TCA cycle?
Carbon dioxide, oxaloacetate, NADH, FADH2
How does ETC generate ATP?
proton gradient used to pump ATP
Primary hormones of the fasted state
glucagon, cortisol and epinephrine
Primary hormone of fed state
insulin
hunger
physiological response, triggered by hypothalamus
satiety
feeling full/satisfied after a meal, determines period between meals
satiation
feeling full/satisfied during a meal, determines how much you eat during a meal
Hypothalamus regulates _____
thirst, hunger and satiety
energy expenditure=
thermogenesis + basal metabolism + physical activity + NEAT
What type of fat confers the most health risk?
visceral fat
What are the health risks of obesity?
elevated blood pressure, diabetes, elevated cholesterol, cardiovascular disease and certain cancers
Body dysmorphia
mental health condition in which you can't stop thinking about perceived flaws or defects in your appearance
What is the most common ED?
Binge eating disorder
What is orthorexia?
an obsession with eating foods that one considers healthy
Anthropometrics
includes weight, stature, abdominal circumference and skinfold measurements
Pros of BMI
assessment of large populations
Cons of BMI
doesn't take into account individual differences
What is DXA?
assessment of bone mineral density, body fat and lean muscle mass
What medications address obesity?
Phentermine, Topiramate, Bupropion, Naltrexone, GLP-1 Agonists, Orlistat
Which obesity medication is the most effective?
GLP-1 agonists
Pros to surgical weight loss
Decreased appetite