Exam Flashcards
What Factors influence your diet?
Food preferences, availability, convenience, cost, culture/ religion, and overall health
Function of Carbohydrates
the primary energy source for all cells in the body, the sole source of energy for brain function, includes fibers vitamins, and minerals
Function of Fats
Facilitates absorption of fat-sol;uble vitamins, production of hormones
Function of protein
building block for all tissues, production of hormones and enzymes
Reasons to change your diet (5)
Fat loss, muscle gain, exercise performance, nutrient deficiency, overall health
Ways to expend energy
Basal metabolic rate, exercise activity, non-exercise activity, thermic effect of food
Def: Neutral Energy Balance
When energy in = energy out
Def: Positive Energy Balance
Energy in is greater than energy out (caloric surplus)
Def: Negative Energy balance
energy in is less than energy out (caloric deficit)
Ketogenic Diet
Mostly fats low carbs
Whole 30
Eat vegetables, fruit, nuts, oils, seeds, seafood and meat, dont eat grains, dairy, sugar, legumes and processed food
Intermittent fasting
Fast for a certain period of time and then eat for a certain period of time
Macro Tracking
Track what you are consuming
How to preserve muscle while losing fat
Adequate dietary protein (1.4g/kg), resistance training and appropriate rate of weight loss
How to assess effectiveness of a diet
is it practical, flexible, sustainable, working. Need to strategize, implement, evaluate and assess constantly
Factors effecting protein quality
Digestibility and amino acid composition
Def: Digestibility
The ability to digest and absorb the protein in a given food
Digestibility of Animal Protein
90-99%
Digestibility of soy and legume protein
less than 90%
digestibility of plant protein
70-80%
Def: Complete protein sources
Protein sources that contain all essential amino acids
Complete protein sources examples
all animal based proteins, quinoa, soy and whey
What does PDCAAS stand for?
Protein digestibility-corrected amino acid score
What is PDCAAS?
scale of protein quality that goes from 0 to 100
What is the PDCAAS of Dairy, egg whites, beef and chicken
100
What is the PDCAAS of soybeans
94
What is the PDCAAS of legumes
50s and 60s
What is the PDCAAS of gluten (wheat protein)
25
Def: Complementary Proteins
Combining plant proteins with various essential amino acids to create full amino acid complement
Recommendation of CFG regarding protein
Eat plant based proteins more often
Reasons of eating plant based protein
- plant-based proteins create significantly lower greenhouse gas emissions
- low quality can be overcome by consuming complimentary proteins
- plant-based diet reduces risk of diabetes and cardiovascular disease
How does a plant-based diet reduce risk of diabetes and cardiovascular disease
decreased saturated fat, increased fiber, decreased cholesterol and more conscious abut nutrient consumption due to restricted diet
Def: Vegan
No animal productd
Def: Lacto-ovo vegetarian
consume eggs and dairy
Def: Pesco vegetarian
consume fish, eggs and dairy
Def: Semi-vegetarian
consume dairy and eggs and red meat/poultry once a week
Def: Protein-energy undernutrition (PEU)
Insufficient intake of protein, energy or both
Impacts of (PEU)
Poor growth (height and/or weight) in children, infections from degradation of antibodies
Marasmus
prolonged period with out enough protein, occurs in babies less than 2 years, slow onset, skin and bones
Kwashiorkor
Sudden change in protein levels, occurs usually around 1 to 3 years, rapid onset (during weening), causes edema (including swollen belly)
How to reverse PEU
Rehydration, electrolyte balance, gradually add protein to diet
Infections caused by PEU
Dysentery, anemia, heart failure and death
Protein recommendations
AMDR 10-35% of total daily energy intake
RDA 0.8g/kg body weight/ day
Def: Nutrigenetics
Examines how gens influence the activities of nutrients
nutrient absorption, nutrient use and metabolism, nutrient requirements and food and nutrient tolerances
Def: Nutrigenomics
Examines how nutrients influence the activities of genes
gene mutation, gene expression and gene programming
Def: Nutritional Genomics
Examines the interactions of genes and nutrients, including both nutrigenetics and nutrigenomics
Single Gene disorders
mutations inherited at birth, influences a single gene, damage to the individual exerted early in life
Multigene disorders
influence several genes, sensitive to interactions with the environment
Single Nucleotide polymorphisms
Change to a single nucleotide in a DNA sequence
Transcription
From DNA to RNA
Translation
from RNA to polypeptide chain
Gene expression
Genes switched on and off through methylation, expressed goes form DNA to mRNA to tRNA to proteins
Pathway of eating impacting gene expression
- Nutrients or phytochemicals consumed
- Directly interact with genetic signals to turn on or off a gene or indirectly interact with genetic signals through substances generated during metabolism
- Gene is activated of silenced
- Protein synthesis increases or decreases
- leads to affect of individuals health such as disease prevention or progression
Anabolic reactions
Building reactions, requires energy
ex: glu+glu=gycogen, Glycerol+fatty acid=triglyceride, AA+AA=protein
Catabolic reaction
Breaking down, releases energy
ex: glycogen= Glu, trigly=Glycerol+fatty acid, protein=AA
ATP
High energy storage compound that captures energy, holds energy through negative charges of phosphates that are vulnerable to hydrolysis, cleaving P groups releases energy
Enzymes
almost always required, facilitates reactions, remains unchanged
Coenzymes
Complex, organic molecules, not proteins, associated with enzymes, required for enzyme function (E.g. Vitamins)
Pyruvate
3-C structure, can be used to make glucose in the liver
Acetyl CoA
2-C structure, cannot make glucose
How does protein enter the metabolism cycle
AA can enter as pyruvate, acetyl CoA or into the TCA cycle
How does carbohydrates enter the metabolism cycle
Glucose to pyruvate (can go back and fourth)
How do fats enter the metabolism cycle
Glycerol enters as pyruvate and fatty acids enter as acetyl CoA
Glycolysis
Starts as glucose, Required ATP to start, 6C split into 2 3C, Net ATP production, Hydrogen attaches to coenzyme (NADH) ends in pyruvate
Anaerobic pyruvate
Converted into lactate when there is not enough oxygen, coenzyme returns H allowing it to grab more, ATP is used in the liver to convert lactate into glucose (shift the burden of energy use to the liver over the muscles)
Aerobic pyruvate
pyruvate enters the mitochondria, a carbon is removed to convert to acetyl CoA (irreversible) process
Acetyl CoA options
Can be converted into fat or can make energy though the TCA Cycle
Converting Fatty acids to Acetyl CoA
oxidize 2 carbons at a time, releases a H in process (more energy), requires oxygen
Glucogenic vs ketogenic
ketogenic can only be converted into acetyl CoA, gulcogenic can be converted to pyruvate and other glucose precursors
Glucogenic entry points
As pyruvate or into TCA cycle (need deamination first)
Ketogenic entry points
Acetyl CoA (need deamination first)
TCA cycle
acetyl CoA comines with oxaloacetate (from carbs) produces H which attach to coenzymes that are sent to the Electron transport chain
Electron Transport Chain
accepts electrons form NADH using oxygen to produce ATP and Water, occurs in the inner mitochondrial membrane
Alcohol Metabolism
Absorbed through the stomach walls and small intestine, liver breaks down alcohol with alcohol dehydrogenase (ADH), produces acetyl CoA and NADH, which is most often converted into fat due to the livers low metabolic needs
Macronutrient uses post-prandial
carbs - stored, fats - used first, protein -build protein in body
Priorities for excess CHO
- Fill glycogen stores
- Used for energy
- Converted to fat
Priorities for excess Protein
- Body proteins
- Used for energy
- Converted to fatty acids
Priorities for excess Fat
- Use for energy
2. Store
Post-absorptive (2-3 hours)
break down liver and muscle glycogen stores and body fat stores for energy use
Beyond Glycogen completion
Body protein broken down and converted into glucose to supply, brain, nervous system and red blood cells and protein and fats broken down to provide energy for other cells
Prolonged fasting
acetyl CoA broken down to make ketone bodies to fuel tissues and brain, energy is conserved by reducing metabolic functions and suppressing appetite, energy used from all sources not just target fat loss
Result of changes in energy balance
Rapid water changes and gradual fat changes
Def: Appetite
Psychological and physical cues (see food, know popcorn at movies even though not actually hungry)
Def: Hunger
Physiological response, hypothalamus, presence or absence of nutrients in blood, can be overridden
Def: Satiation
Stop eating, feeling of fullness
Def: Satiety
opposite to hunger, sensing nutrients in blood, do not start eating again, overriding factors include stress, boredom, favorite food, social cues
Food Intake cycle
- Hunger (psychological influences)
- Seek food and start meal (sensory influences)
- Keep Eating (Cognitive influences)
- Satiation - end meal (postingestive influences)
- Satiety - several hours later (postabsorpitive influences)
Physiological influence of food intake
empty stomach gastric contractions absence of nutrients in small intestine GI hormones Endorphins are triggered by the smell, sight or taste of foods, enhancing the desire for them
Sensory influences of food intake
Thought sight smell sound taste of food
Cognitive influence of food intake
Presence of others/ social stimulation
Perception of hunger/awareness of fullness
Favorite foods/ foods with special meanings
Time of Day
Abundance of available food
Postingestive influences of food intake
food in stomach triggers stretch receptors
nutrients in small intestine elicit hormones (CCK)
Postabsorptive influence of food intake
nutrients in the blood signal the brain about their availability, use and storage
nutrients dwindle, satiety diminishes
hunger develops
Components of energy expenditure
- Basal metabolism - basal metabolic rate and resting metabolic rate (50-65%)
- physical activity (highly variable) (30-50%)
- Food consumption - thermic effect of food (10%)
- adaptation responses
Factors increasing BMR
Height, growth, body composition, fever, stress, environmental temperature (increases at both extremes), hormones
Factors decreasing BMR
age, fasting/starvation, malnutrition, sleep
Influences of estimating energy requirements
sex, growth, age, physical activity, body composition and size
Low-Carbohydrate diet
Uses glycogen stores first, then body proteins through gluconeogenesis, ketones found in urine from incomplete breakdown of fat, causes rapid weight loss due to glycogen loss, lean muscle loss, fluid loss and some fat loss
Ketogenic diet for athletic performance study
3 groups - high CHO, periodized CHO and ketogenic diet (tested over 3 week training camps with 2 workouts a day)
ketogenic diet performed worse, was less efficient, more oxygen required for the same race speed
Ketogenic Diet on Bone Health
Preliminary research showed reduced markers of bone health after just 3.5 weeks, values did not fully rebound when returned to normal diet
Total body mass
includes body fat (makes up about 20%), muscle, bones and organs
Lean body mass
includes muscle, bones and organs
lean soft tissue mass
includes muscles and organs
Total body muscle mass
includes muscle
Body fat composition distribution
ideal amount depends on gender (F25% - 12% essential, M15% - 3% essential)
Body fat location distribution
Visceral fat - surrounds vital organs causes central obesity
Subcutaneous fat- other regions
Waist circumference as an indication of visceral fat
women less than 35 in
men less than 40 in
Apple shape
android obesity, high health risk
Pear shape
gynoid obesity, less high health risk, may even improve health
Methods to assess body fat
Waist circumference - common with healthcare practitioners
Skinfolds - at several sites
Bioelectrical impedance - fat provides more resistance to electrical current ( more accurate than above)
Dual energy x-ray absorptiometry (DEXA) - low dose x-ray, gold standard
MRI- also gold standard, used to compare and contrast with DEXA
Body Mass Index (BMI)
relative weight for height weight in kg /height in m^2
based on population averages, related to disease risk, increased accuracy with waist measurements
BMI Classifications
Underweight: < 18.5
Healthy Weight: 18.5 to 24.9
Overweight: 25.0 to 29.9
Obese: 30.0+
Obesity
Excess or abnormal body fat that can impair health
Obesity Diagnosis
Anthropometric - BMI, waist circumference, boy fat %, body fat location
and
Impact on health - BP, lipids, glucose, physical symptoms, psychopathology, functional limitations/well being
Obesity prevalence
Obesity prevalence increasing, overweight prevalence remain the same (overweight becoming obese)
Health Risks associated with being over wieght
CVD, diabetes, cancer, inflammation and metabolic syndrome, increase mortality rate
BMI affect on mortality
BMI 22.5-24.9 = optimal survival
BMI 30-34.9 = 3 years loss of life
BMI greater than 40 = 10 years loss of life
Social and psychological affects of obesity
Discrimination and judgment
perceived laziness and lack of self-control
embarrassment, rejection, shame and depression
Fit fat paradox
Being overweight but fit counteracts increased risks and is healthier than normal weight unfit individuals
Health risks associated with underweight
fighting against wasting diseases (lack of energy stores)
menstrual irregularities and infertility
osteoporosis and bone fractures
increased risk of mortality
Fat Cell development
Energy in greater than energy out causes it to be stored as adipose tissues, body fat reflected in number of fat cells - grow must rapidly in first year, obese individuals have more fat cells
increase # of cells then cells increase in size then increase # of cells again
when lose fat # of cells remain
Lipoprotein Lipase (LPL)
Uptake of triglycerides into tissues, higher in obese people (Predisposed, have more LPLs), active in varying body regions depending on sex, weight loss increases activity
Set-point theory
Body likes to maintain homeostasis even with weight, adjusts to original weight, increased metabolism during weight gain and reduce metabolism during weight loss
genetic causes of overweight and obesity
genetics may determine a predisposition to obesity, identical 2 x more likely to be same weight, but genes interact with diet and physical activity
ob gene
Codes for leptin protein produced in adipose tissue, nicknamed obesity gene, promotes negative energy balance by suppressing appetite and increases energy expenditure, mutations are rare, leptin resistance
Adiponectin
protein regulation energy homeostasis
Lower concentration in obesity
secreted from adipose tissue
increases insulin sensitivity
Ghrelin
protein regulation energy homeostasis
Increases in concentration with fasting, decreases after a meal
Secreted form the stomach
Stimulates appetite
Leptin
Protein regulation energy homeostasis
high concentration in obesity
secreted from adipose tissue
suppresses appetite and increases energy expenditure
PYY
Protein regulation energy homeostasis
increases in concentration after a meal
Secreted form the CNS and GI tract
suppresses appetite
Types of fat
white adipose tissue - stores fat for other tissues to use, main type for fat in adults
Brown adipose tissue - releases stored fat as heat, abundant in newborns, lots of mitochondria, activated by uncoupling proteins
Environmental causes of overweight and obesity
Overeating - abundance of high kcal, inexpensive, tasty and advertised foods
Physical inactivity - sedentary behaviors which require little energy and replace more vigorous activity
Obesity treatments
WHO recommends 5-10% reduction in body weight as treatment through negative energy balance achieved by exercise training and hypocaloric diet
Weight loss strategies
small changes, moderate losses (10-20lbs/yr), reasonable goals
Physical activity recommendations
150 min of moderate to vigorous activity per week
Discretionary kcal allowance
Window between energy intake required to meet nutritional needs and energy expenditure, increased with exercise
Strategies for weight gain
energy dense foods, regular meals and snacks, use of nutrient-dense caloric beverages, exercise(ST), if aerobic training HITT, balance is key
Relative Energy deficiency in sport
Low energy availabilities effect on immunological, menstrual, bone health, endocrine, metabolic, hermatological, growth + development, psychological, cardiovascular and gastrointestinal function
Energy availability equation in athletes
energy availability =energy intake - exercising energy expenditure, includes energy needed to recover from workouts
Early symptoms of RED-S
Menstrual disturbances, initial weight loss, decreased mood status, decreased RMR, lower Resting HR, low BP
Mid Symptoms of RED-S
weight gain+ swelling, stress reactions/fractures, decreased sex hormones and leptin, decreased T3, decreased IGF-1, decreased ferritin, increased cortisol, decreased fasting
Long-term symptoms of RED-S
Recurrent stress fractures year to year, increased MSK injuries, increase illnesses, impaired performance, gut issues, inability to lose weight
Menstrual disorder symptoms
lower RMR, lower estradiol, higher cortisol, trend towards lower T3
Consequences of RED-S
Osteopenia or osteoporosis, low of adaptation to training, inability to lose weight, reduced fertility, thyroid dysfunctions
What drives RED-S in athletes
body image - societal and sport pressures
drive for thinness - lighter = faster
exercise dependency and eating disorders
making weight
unintentional LEA due to increased training volume
lack of understanding differences in male and female maturation
Puberty in male athletes
primarily increase in muscle mass and strength
increased testosterone brings about sex differences
greater cardiac blood and lung volumes
increased Hemoglobin
Puberty in female athletes
primarily increase in adipose tissue
initial dip in performance to adapt to new body
How to heal from RED-S
fuel around training, no fasted training or diets, CHO are essential, within day energy balance - no 3-4 hours blocks without food, low fiber, strength training, seek professional help early
