Nutrition Exam 4 Final Review Summer 2015

AdenosineTriphosphate (ATP)

•Immediatelyusable energy compound–Synthesizedby the body–Mostdirectly used for muscle contractions•Anaerobic–Phosphocreatine–Fastglycolysis (CHO)•Aerobic–Slowglycolysis (CHO, FAT, PRO)

Phosphocreatine(PCr)

•High-energycompound that can be used to re-form ATP from ADP–PCr+ ADP àATP + Cr–Fastestmethod of producing ATP•Functionsas the major source of energy for events lasting up to 1 minute•Jumping,lifting, throwing, sprinting•Creatine–Organicmolecule in muscle cells that is synthesized from 3 amino acids: glycine,arginine,and methionine.

Catabolism - the breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy; destructive metabolism.

Anabolism - the synthesis of complex molecules in living organisms from simpler ones together with the storage of energy; constructive metabolism.

Metabolism - the chemical processes that occur within a living organism in order to maintain life.

MacronutrientDistribution

•CHOand PRO recommendations should be examined in terms of gramsper kilogramof body weight as opposed to percentage of total calories– Accountsfor individual body size–g/kgof body weight is more closely related to absolute needs of athletes.

DMAA - Containing dietary supplements are illegal and their marketing violates the law. Based on the scientific information reviewed by FDA, DMAA is not a dietary ingredient. No, FDA does not have any information to demonstrate that consuming DMAA is safe.

BottomLine on Supplements

EFFORTAND CONSISTENCY and proper diet aremuch more important for your / an athlete’s training than it is to find theperfect supplements! Justlike there’s no magic weight loss drug, there are no magicweight/strength/muscle gaining supplements!

CarbohydrateLoading – Necessary?

•Depletionof glycogen via exercise during tapering phase of training followed by high CHOdiet (relative!) 3 days prior to competition•Higher%CHO intake the night before competition•Increasesof 50-85% in glycogen storage•Onlyuseful for athletes competing in continuous, intense aerobicbouts (60-90 mins) orrepeated shorter events (example – soccer match).

CHORecommendations – Another Viewpoint.

Dr.Jeff Volek, Dr.Stephen Phinney:–Highcarb diets are detrimental to health.–Oncean athlete is “low-carb” adapted (~4 weeks), a low-carb diet will not lead todecrements in performance! –(Earlierstudies showing the necessity of “carb-loading” and high-carb diets, were basedon people not given enough time to adaptto a low-carb diet).

Hydrationfor Athletes

•Drinkfluids consistently throughout the day•Ifpossible, continue throughout training or competition (even swimming or wintersports)•Followingexercise, gradually drink to restore initial weight.

Carbohydrate Loading – Necessary? •Depletion of glycogen via exercise during tapering phase of training followed by high CHO diet (relative!) 3 days prior to competition •Higher %CHO intake the night before competition •Increases of 50-85% in glycogen storage •Only useful for athletes competing in continuous, intense aerobic bouts (60-90 mins) or repeated shorter events (example – soccer match).

CHO Recommendations – Another Viewpoint.

Dr. Jeff Volek, Dr. Stephen Phinney: –High carb diets are detrimental to health. –Once an athlete is “low-carb” adapted (~4 weeks), a low-carb diet will not lead to decrements in performance! –(Earlier studies showing the necessity of “carb-loading” and high-carb diets, were based on people not given enough time to adapt to a low-carb diet).

Hydration for Athletes

•Drink fluids consistently throughout the day •If possible, continue throughout training or competition (even swimming or winter sports) •Following exercise, gradually drink to restore initial weight.

PROBenefits

•Boostanabolic effect of exercise–Increasedlean body mass•(NEVERuse the expression “lean muscle mass”)–Increasedstrength over time.

•Wheyprotein provides fast-acting protein synthesis.

•Caseinprotein provides sustained protein synthesis.

•Animal-basedproteins are superior to soy-based proteins.

The Female Athlete Triad is a syndrome of three interrelated conditions that exist on a continuum of severity, including:Energy Deficiency with or without Disordered Eating Menstrual Disturbances/ Amenorrhea Bone Loss/Osteoporosis.

Hydrationfor Athletes

•Drinkfluids consistently throughout the day

•Ifpossible, continue throughout training or competition (even swimming or wintersports)•Followingexercise, gradually drink to restore initial weight.

Milk for Recovery!

•Contains both whey and casein protein •Chocolate Milk: 3:1 CHO:PRO ratio – contains sucrose (good?/bad?)

•Shown to enhance both endurance and resistance training recovery

•Provides fluids for hydration

•Replenishes glycogen stores

•Vitamins and minerals
BranchedChain Amino Acids

•Essentialamino acids: leucine, isoleucine, andvaline.

•Highconcentrations in whey protein (26%), milk (21%), and other high-qualityprotein sources.

•Augmentedprotein synthesis and reduced protein degradation (recovery), possibly delayfatigue.

•Dosage:9-15 g total throughout exercise•Usefulwhen restricting energy intake.

Fat

•Fatoxidation–Utilizationof fat during low or moderate aerobic activity–Fattyacids and triglycerides in the bloodstream–Fatstored in body cells (adipose tissue)•Highenergy (9 kcal/g), but cannot support high-intensity exercise as fat•Percentagevs. relative amount of fat vs. chooxidized (intensities/duration).

Fat also provides body fuel; use of fat as fuel depends on the duration of the exercise and the condition of the athlete.
For moderate exercise, about half of the total energy expenditure is derived from free fatty acid metabolism. If the event lasts more than an hour, the body may use mostly fats for energy. Using fat as fuel depends on the event's duration and the athlete's condition. Trained athletes use fat for energy more quickly than untrained athletes. Consumption of fat should not fall below 15 percent of total energy intake because it may limit performance. Athletes who are under pressures to achieve or maintain a low body weight are susceptible to using fat restriction and should be told that this will hinder their performance.Fat may contribute as much as 75 percent of the energy demand during prolonged aerobic work in the endurance-trained athlete. There is evidence that the rate of fat metabolism may be accelerated by ingesting caffeine prior to and during endurance performance. However, insomnia, restlessness and ringing of the ears can occur with caffeine consumption. Furthermore, caffeine acts as a diuretic and athletes want to avoid the need to urinate during competition.

Yes!

MacronutrientDistribution

•CHOand PRO recommendations should be examined in terms of gramsper kilogramof body weight as opposed to percentage of total calories–Accountsfor individual body size–g/kgof body weight is more closely related to absolute needs of athletes.

CHORecommendations – Another Viewpoint

Dr.Jeff Volek, Dr.Stephen Phinney:–Highcarb diets are detrimental to health.–Oncean athlete is “low-carb” adapted (~4 weeks), a low-carb diet will not lead todecrements in performance! –(Earlierstudies showing the necessity of “carb-loading” and high-carb diets, were basedon people not given enough time to adaptto a low-carb diet).

Phosphocreatine(PCr)d to u

•High-energycompound that can be used to re-form ATP from ADP–PCr+ ADP àATP + Cr–Fastestmethod of producing ATP•Functionsas the major source of energy for events lasting up to 1 minute•Jumping,lifting, throwing, sprinting•Creatine–Organicmolecule in muscle cells that is synthesized from 3 amino acids: glycine,arginine,and methionine.

Carbohydrate

•Anaerobicglycolysis(inthe cytoplasm)–Breakdownof glucose or glycogen in the absence of oxygen–1glucose molecule produces 2 ATP•Providesenergy for high-intensity activity lasting 30 s to 2 mins (2ndfastest method)•Rapidaccumulation of lactate slows ATP production -> fatigue.

Carbohydrate

•Aerobicglycolysis(inthe mitochondria)–Breakdownof glucose or glycogen in the presence of oxygen, yielding 2 pyruvate–2pyruvatemolecules produce 28-30 ATP•Providesenergy for activity lasting longer than 2 mins(slowest method)

•95%of ATP produced aerobically in the mitochondria

•Canbe sustained for hours.

Fat

•Fatoxidation–Utilizationof fat during low or moderate aerobic activity–Fattyacids and triglycerides in the bloodstream–Fatstored in body cells (adipose tissue)

•Highenergy (9 kcal/g), but cannot support high-intensity exercise as fat

•Percentagevs. relative amount of fat vs. chooxidized (intensities/duration).

When someone is clinically overweight but still has a good body shape or able to run faster or gym harder than a slimmer person.

Fat9 kcal/gm
Carbohydrates4 kcal/gm

Protein4 kcal/gm

Alcohol7 kcal/gm

.Directcalorimetry

Measuresbody heat

Indirectcalorimetry

Collectingexpired air

.EnergyExpenditure

Basalmetabolic rate (BMR)

Minimum amount of energy in afasting state

Restingmetabolic rate (RMR)

Non fasting-6% higher than BMR

Physicalactivity

Thermiceffect of food

Adaptivethermogenesis

Brown fat

. Energy Expenditure

Basal metabolic rate (BMR)

Minimum amount of energy in a fasting state

Resting metabolic rate (RMR)

Non fasting-6% higher than BMR

Physical activity

Thermic effect of food

Adaptive thermogenesis

Brown fat

.ThermicEffect of Food (TEF)

Energyused to digest, absorb, and metabolize food nutrients.

~5-10%above the total calories consumed.

TEFis highest for protein > carbohydrate > fat MacronutrientTEF differences are notsignificant with regard to losing weight.

Thermogenesis

Non-voluntaryphysical activity triggered by overeating or cold environment.

Fidgeting,shivering, maintenance of muscle tone, postureIncreasesin the sympathetic nervous system activity.

Possiblyresists weight gain.

.Satiety Regulator

The hypothalamus When feeding center is stimulated, it signals you to eat.

When satiety center is stimulated, it signals you to stop eating.

Sympathetic nervous system

When activity increases, it signals you to stop eating.

When activity decreases, it signals you to eat.

.ClassicWeight Loss Paradigm.

Calories in ---- Calories Out

Is it this easy?

Commonidea surrounding weight loss:“TheFirst Law of Thermodynamics states that energy can neither be created nordestroyed. It can only be converted from one form to another. In other words,energy just doesn’t just magically disappear; it must be converted to somethingelse. In the case of any excess calories you ingest, they will be stored asfat, used to accommodate an increase in lean tissue mass, or dissipated as heatthrough thermogenesis. Manipulating the proportion of protein, fat andcarbohydrate you eat each day will not excuse you from the Law ofThermodynamics.”

“Iwas somewhat confused to see this [a nutritional description of the energybalance equation] Surely the nutritional scientists did not really believe this, right? I mean, any idiotundergraduate students knows that the 1st Law is only useful in a closedsystem, and humans live on the planet Earth, not in an insulated box. Right?”…“Unfortunately,to a physicist this energy balance hypothesis looks like a silly hand-wavingexercise, not a serious argument. Frankly I was flabbergasted when I first readthis article. This conservation of energy argument is on the same scientificlevel as the ridiculous “drink cold water to lose weight” idiocy. A humanorganism is:1) Not in thermal equilibrium with theirenvironment. Last time I checked I have a body temperature around 38 °C andspend most of my time in 21 °C rooms. 2) Capable of significant mass flows (e.g.respiration). 3) Capable of sequestering entropy (e.g. proteinsynthesis). Iswearing a sweater fattening (by insulating you from your environment)?”

-RobertMcLeod (physicist)

.Claesson Et Al.

Body-weight and waist circumference ↑significantlyonly in the candy group.

LDL cholesterol ↑ in the candygroup.

BMRincreased only in the peanut group

CONCLUSION: Two weeks of snacking basedon peanuts (fat-protein) is better for you than candy (high GI carbs).

Not all calories are created equally.

.Layman Et Al.

Dietswere equal in kcals and fat (30% energy intake) but differed in proteincontent and the ratio of carbohydrate:protein.

Group1: RDA Recommended CHO:PRO Ratio 3.5gto 1g (CHO: PRO)

Group2:

1.5gto 1g (CHO: PRO)

.Estimation of Body Fat

Underwater weighing Most accurate Fat is less dense than lean tissue Fat floats.

DXA An X-ray body scan thatallows for the determination of body fat.

.Estimationof Body Fat

Underwaterweighing Mostaccurate Fatis less dense than lean tissueFat floats.

BodPod Airdisplacement Skinfolds.

.BodyFat Distribution

“Apple”(android) obesityAssociatedwith more heart disease, HTN, Type II DiabetesAssociatedwith greater amounts of visceral fatEncouragedby testosterone and excessive alcohol intakeDefinedas waist measurement of >40” in men and >35” in women.

.BodyFat Distribution

“Pear”(gynecoid)obesityEncouragedby estrogen and progesteroneAftermenopause, “apple” obesity may appearLesshealth risk than “apple” obesity (less fat surrounding internal organs).

“Semi-starvation”Diets

Bodydefends itself against weight lossBasalMetabolic Rate drops during weight loss and make it more difficult to loseweightActivityof lipoprotein lipase increases making it more efficient at taking up fat forstorage.