Nutrients and Energy Flashcards
Nutrition
act of obtaining and using nutrients to support all the processes required for life.
What are the 6 classes of nutrients needed for our body?
carbs, lipids, proteins, vitamins, minerals, and water
carbs
ORGANIC, ENERGY YIELDING, macronutrient
lipids (fats)
ORGANIC, ENERGY YIELDING, macronutrient
proteins
ORGANIC, ENERGY YIELDING, macronutrient
vitamins
ORGANIC, micronutrient
minerals
inrorganic, micronutrients
water
inorganic
macronutrient
need more than 1g daily in diet
micronutrient
need less than 1 gram daily. typically a vitamin or mineral.
What makes up basal metabolism?
Respiration ○Circulation ○Temperature regulation ○Cell activity ○Maintenance Everything else
Energy value of food is measured in:
kcal (NOT CALORIE) = 4.184 J
REE
BMR = resting energy expenditure. varies by person: ○LEAN BODY MASS!!!!!! Period. All else are secondary ○Body size ○Sex ○Age ○Heredity ○Physical condition, Nutrition ○Climate
Note skin and energy relationship
Those who are taller have more skin covering them, which means they have more surface area to dissipate heat, which means they need a HIGHER BMR in order to compensate for this.
resting metabolic rate (RMR)
Energy required in a rested, fasted state to maintain vital organ function
○Measured while laying down and resting at least 30 minutes prior to the determination
basal metabolic rate (BMR)
RMR measured soon after waking in the morning, after a 7-8 hour resting period, and at least 12 hours after the last meal
○RMR and BMR differ in practice by less than 10%, thus may be used interchangeably in clinical care
What are the sources of kcals? What are their energy value? Where does OH fit into this?
- macronutrients.
carbs: 4 kcal/g
lipids: 4 kcal/g
proteins: 9 kcal/g - OH is NOT a nutrient, tho is provides 7kcal/g. it instead inhibits growth and maintenance and repairs of the body.
nutrient dense
provide maximal amounts of nutrients for minimal number of calories
energy dense
high in fat and have a low water content with lower amount of essential nutrient
empty calories
Provides primarily calories, and little else (ex. soda)
kilocalori? What if it is a calorie?
amount of heat required to raise the temperature of 1 kg of water 1 degree Celsius. If it is a calorie, switch kg to g.
DRI dietary reference intakes. What are they?
list the amount of each nutrient your body needs daily. “I need this much intake every day”
- Estimates average requirment (EAR)
- Adequate Intake (AI) level
- Tolerable upper intake level (UL)
- Recommended Dietary allowance (RDA)
- AMDR
Estimated average requirements (EAR)
Amount estimated to be adequate for HALF (con) the healthy individuals of a specific age or sex
○Not effective for individuals as this value is a median for a group. Literally in the middle of the curve
recommended daily allowances (RDA)
Nutrient-intake goals for individuals to meet nearly all healthy persons requirements at any stage in life
○Defined as 2 standard deviations (97%) above EAR
○Can only be established for nutrients with EARs (con)
adequate intake
Nutrient intake goals for individuals, based on observed/experiments. As in, EAR and RDA have to not work for you to take this route.
○For those with no set EAR and RDA
○Ex. No RDAs for infants 0 to 6 months of age; only AIs
Tolerable Upper Intake Levels (UL)
Highest level of usual daily nutrient intake likely to be safe for a population (an attempt to find out how much is too much)
○Not all nutrients have an UL
○Lack of UL does not mean there is no toxicity
○Insufficient research
Acceptable Macronutrient Distribution Ranges (AMDR)
Recommended percentage intakes for the macronutrients:
45-65% kcalories from carbohydrate
○20-35% kcalories from fat
○10-35% kcalories from protein
All this stuff varies by the level of activity the person has in a day.
In terms of accuracy methods, is EAR good enough? Where do patients was to be?
Anything below EAR is inadequate. Patients want to be between the EAR and the upper daily limit. (know that you need to be between RDA and UL…exam worthy)
Energy expenditure
EE ~ Basal EE (BEE) + diet thermogenesis + activity (walking, sports, etc)
What’s the most accurate way to measure energy expenditure?
Measurement via direct (measures total heat lost from body) and indirect Calorimetry (assess respiratory gas exchange…MOST ACCURATE in clinical practice) estimate . note that all of this varies by age and activity of the person
Energy balance
Based off nutrient intake and how it makes the energy we use and how it is expended by our body. Intake = proteins, carbs, lipids, and OH (though smallest contributer). Output = energy expended = basal metabolism, physical activity, amount of heat lost from food
Difference between positive, negative, and neutral balance?
neurtral: intake = outtake. no weight gain.
positive: intake is greater than outtake (weight gain..energy stored as adipose)
negative outtake (intake is less than outtake. weight loss)
functions of adipose? storage?
Protect, support organs, regulate temperature. stored:
○Visceral adipose tissue (VAT), risk for metabolic syndrome. fat is stored UNDER fat, around vasculature and vital organs and around abdominal area.
○Subcutaneous adipose tissue (SCAT) -> found under skin and above the mucsle
○Essential Fat (found around the heart)
What hormones are secreted from adipose? what is the purpose?
adipokines, responsible for immune and inflammatory processes.
Difference between adipose hypertrophic and hyperplastic growth
trophic: size of the adipocytes
plastic: NUMBER of adiposcytes
Hunger -
•Satiation -
•Satiety -
Hunger - need for food
•Satiation - signal to stop eating
•Satiety - interval between the next drive to eat
what is the drive to eat?
Balance between energy expenditure, and obtaining resources for new energy
○Long term - energy stores
○Short term - hypoglycemia, hormones
•Energy status + brain centers + efferent signals
What plays a large role in our hunger and satiety?
hypothalamus
ventral medial nucleus (VMN)
lateral Hypothalmic area (LHA)
Neurotransmitters:
ventral medial nucleus (VMN VMN = responsible for our satiety
LHA =Lateral hypothalmic area (LHA) = responsible for our Hunger
neurotransmitters: communicates between ventral medial nucleus and lateral hypothalmic area.
What is the role of gastric stretching?
Stimulates the vagus, saying that food is present. Circulating nutrient levels is also caused by vagal stimuli.
GI hormones:
Orexigenic:
anorexigenic:
Orexigenic:(stimulate feeding)
anorexigenic:(inhibit feeding)
Leptin
plays role in long and short term signaling acts directly on hypothalmus ventral medial nucleus and lateral hypothalmic area. also acts on NYP
NYP neurotransmitter
once sitmulated form leptin, increases appetite and releases orexigenic proteins to help initiate feeding to initiate energy stores.
Agrp neurotransmitter
increases appetite and releases orexigenic proteins to help initiate feeding to initiate energy stores.
POMC
It is an anti orexigenic protein. It’s a anorexigenic protein. works to decrease satiety (decrease appetite)
Ghrelin
Main site of synth: gastric X/a like cells (fundus of the stomach)
Secretion Pattern: increases prior to meal, decreased by food intake.
Effect on food intake: stimulates food intake
CCk
Main site of synth: proximal intestinal I cells
Secretion Pattern: stiulated by duodenal presence of fat and protein. causes gallbladder contraction.
Effect on food intake: promotes meal termination and reduces meal size
Peptide YY3-36 (PYY)
Main site of synth: dista;-intestinal L cells
Secretion Pattern: stimulated by presence of fat in the lumen
Effect on food intake: reduces appetite and food intake
Glucagon-like peptide 1 (GLP-1)
Main site of synth: distal-intestinal cells
Secretion Pattern: stimulated by presence of nutrients in the lumen
Effect on food intake: short-term inhibition of food intake. works with glucose and increases secretion of insulin
L CELLS
Pancreatic polypeptide (PP)
Main site of synth: pancreatic F cells
Secretion Pattern: released in proportion to calories ingested
Effect on food intake: reduces appetite and food intake
List all the processes in sequence for when one is feeding
Ghrelin↓, PYY↑, GLP1↑, CCK1↑, Leptin↑ → modulate AGRP, NYP, POMC → orexigenic proteins↓ anorexigenic proteins↑ →suppressed appetite
List all the processes in sequence for when one is fasting
→ Ghrelin ↑, PYY↓, GLP1↓, CCK↓, Leptin↓, modulate AGRP, NYP, POMC →orexigenic proteins↑, anorexigenic proteins↓ → increased appetite
What happens if you eat high volume foods? what foods contribute to weight loss?
Stomach is distended and it keeps you satiated longer.
For weight loss: Choosing high-volume, low-energy dense (low cal) foods can contribute to weight loss. You must know this.
what is special about eating protein?
energy producing and most satiating due to circulating amino acids
what do you expect when eating high fiber foods?
gastric stretching and delayed stomach emptying - promote satiety
what do you expect when eating high fat foods?
high levels leads to satiety signals (weak effect)
what are the 3 components of total energy expenditure?
- basal (the bulk of the energy we spend daily. keeps our vital organs on that A1)
- physical activitity
- thermic effect of food….as it consumes 10% of our daily energy to process food
what effects our basal metabolic rate?
●Energy expenditure at rest (awake), 12 hours after last meal
●Varies based on age, sex, weight, etc.
●BMI effects due to varying active tissues (adipose is less metabolically active than muscle)
●Falls about 10% during sleep, 40% during starvation (our needs throughout the day changes)
●Average BMR ~2000 kcal/day (70kg male)
what is the most variable component of energy expenditure?
physical activity.
what contributes to the amount of energy needed in terms of physical activity? what can be done to facilitate weight loss in this department?
○Muscle mass
○Frequency, intensity, and duration
for weight loss: High level of activity (~1hr.day) and self monitoring for long term weight loss
What is BMI?
- a measure of our energy stores. it is a non-specific measure of body cell mass.
what is IBW (ideal body weight?
ideal weight for height, based on equations.
what is composition?
Adipose/muscle ratio, muscle mass, nutritional status, bone mass, inorganic compounds. more specific than IBW.
how does skinfold thickness relate to total body fat? what else could be used to assess body composition?
it reflexes changes in total body fat, with triceps skinfold being the most common. you could also use bioelectrical impedance,, which uses alternating current to two limbs in order to measure resistance between the 2 in order to relate that to our body compositions. could also use MRI, daxter scans
BMI
weight (kg)/ height (m)^2
what are the classifications for the BMI numbers?
Underweight BMI<18.5 kg/m2
○Healthy weight BMI 18.5-24.9 kg/m2
○Overweight BMI 25.0-29.9 kg/m2
○Obesity BMI >30 kg/m2
○BMI >25 kg/m2 increase risk of premature death/disability
○Variation, interpret based on frame size, sex, age, etc
who can get bariatric surgery?
those with BMI above 35 and are commorbidities for heart failure and such
what valuies in men and women put them at increased risk for cardiovascular disease? what about waist to hip ratio?
man: greater than 40 in, greater than 0.9
woman: greater than 35 in, greater than 0.85
What are the health consequences for obesity?
●Psychological burden, mechanical effects on joints, increased free fatty acids, leptin, and proinflammatory adipokines (also at increaed risk for osteoarthritis)
●Dyslipidemia - VLDL (↑), triglycerides (↑), cholesterol (↑), LDL (↑), HDL(↓) →→ atherogenesis
●Metabolic syndrome, triglycerides (↑), HDL (↓), BMI/WHR (↑), hypertension, microalbuminuria
what did the framingham study show?
1 unit increase BMI, increased risk of heart failure 5% in men, 7% in women
what are health consequences for the the heart due to obesity?
Cardiovascular disease- inflammation, thrombosis, hyperglycemia, atherogenesis, and adipokines → risk for Hypertension, heart failure, and CAD
what are health consequences for the pulmonology due to obesity?
alveolar hypoventilation, Obstructive sleep apnea, pulmonary HTN, dysrhythmia, mortality (↑). also leads to right sided heart failure, secondary to elevated pressures in the lung (Cor pulmonale)
what are risk factors for DM2?
BMI 25-30 kg/m2, 3-4x risk of T2DM in men and women >55 and BMI >40 kg/m2, 12-18x risk of T2DM in men and women >55
what is the link between insulin resistance and DM2? how does this effect the pancrease?
there is increased insulin reisstance from adipokines in DM2 patients. Increased Insulin resistance leads to increased production and pancreatic burnout
what releases leptin? what does leptin do?
- adipocytes
- helps suppress appetite
Note: so long as you have the leptin receptor, you can respond to leptin, and you will lose weight.
Which of the follow macronutrients yields the highest amount of energy per gram?
a) Protein
b) Vitamin
c) Mineral
d) Lipid
e) Complex Carbohydrate
f) Simple Carbohydrate
d)Lipid
Which of the following best describes a substance that works not only as a way to decrease food intake, but also plays a close role in insulin secretion?
a) A hormone from the hypothalamus
b) A hormone produced from ileal L cells
c) A hormone produced from duodenal I cells
d) A neurotransmitter from the hypothalamus
e) A hormone secreted the gastric antrum
b)A hormone produced from ileal L cells. these guys produce GLP-1
A 55 year old male presents to your clinic for a routine well examination. He states that he has been feeling well and has no complaints. He is a never smoker and does not drink alcohol. His blood pressure is 145/90, pulse 85, O2 saturation 97% on room air, respiratory rate 16, and BMI 40 kg/m2. Cardiovascular and Pulmonary examination shows no abnormalities. During the counseling of the patient, which of the following is he at increased risk for given his examination today?
a)Mechanical damage to joints leading to osteoarthritis
b)Increased circulating levels of triglycerides
c)Heart failure
d)Atherogenesis
e)Obstructive Sleep Apnea
f)All of the above
46
f)All of the above
