final donald layman nsp webinar ppt 01-15-18 · branched‐chain amino acids bcaas metabolic...
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1/15/2018
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OptimizingProtein…… inaCarbohydrateWorld
Donald K. Layman, Ph.D.
Professor Emeritus
Department of Food Science & Human Nutrition
University of Illinois at Urbana‐Champaign
Theconfusedconsumer…
Myth: “Adults eat more protein than they need”
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Recommended Dietary Allowance (RDA)The lowest level of dietary protein intake that will balance the losses of nitrogen from the body … in persons at energy balance with modest levels of physical activity …
Myth: “Adults eat more protein than they need”
Minimum intake to prevent deficiencies
versus
Optimum intake for health
DietaryReferenceIntake
AcceptableMacronutrientDistributionRange
RDA = Recommended Dietary Allowance
SafeRangeofDietaryProtein(DRI)
DietaryReferenceIntake(forprotein)
AcceptableMacronutrientDistributionRange
0.8g/kg~56g/d10%En
>3.0g/kg~225g/d35%En
P P
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Theparadigmshift… from Pyramids to Plates
• avoid fat• eat grains• daily net servings
• vegetables• protein (and dairy)• balanced meals
2010
What’s new in protein research:
health of skeletal muscle critical for long‐term health
age‐related “sacropenia”
• functional mobility
• metabolic health
aging reduces efficiency of protein use
meal distribution of protein
A “Muscle‐centric” View of Nutrition
Am J Clin Nutr 2006; 84:475
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Metabolic Advantage of Protein(with reduced carbohydrate intakes)
improves body composition protects skeletal muscle; targets fat loss
increases metabolic rate enhances satiety
reduces snacking
reverses the Metabolic Syndrome↓ TG, ↑ HDL, ↑ LDL size↓ FBG, ↓ post‐prandial insulin, ↓ BP
Minimum versus Optimum? what are the critical health outcomes?
Growth versus Aging
Protein RDA = 2.2 1.5 1.0 0.8 ……………………………………….. g/kg?
Meal effects on muscle protein balance
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Muscleproteinsynthesisafteramealinyoungversusolderadults
muscle protein syn
thesis
Katsanos et at AJCN 82: 1065, 2005
Meal containing:15 grams of protein
(7 g essential amino acids)
Aging reduces the Efficiency of protein use
Cause (?)
• reduced capillary blood flow
• reduced membrane transport
• reduced metabolic signaling***
Non‐essential Amino AcidsArgAlaAsnAspCysGluGlnGlyProTyr
Essential Amino AcidsLysMetTrpThrLeuPheHisValIle
Limiting AA’s
Why do we need protein = “Amino Acids”
building blocks for new proteins
multiple other metabolic roles
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Non‐essential Amino AcidsArgAlaAsnAspCysGluGlnGlyProTyr
Essential Amino AcidsLysMetTrpThrLeuPheHisValIle
Why do we need protein = “Amino Acids”
= leucine
= valine= isoleucine
Branched‐chain amino acids
BCAAs
Metabolic signals from amino acids
amino acids
Neurotransmitters(mood, appetite)
gut hormones(GLP1, CCK, PYY)
GCN2(integrated stress response)
SIRT‐1, PGC1(mitochondriabiogenesis)
vascular health(nitric oxide)
Leucine – mTORC1(protein synthesismuscle health)
Aging reduces the efficiency of protein use …… but does not impair the capacity to respond
muscle protein syn
thesis
Katsanos et at AJCN 82: 1065, 2005 Symons et al AJCN 86:451, 20074 oz of beef
~32 g protein~ 15 g EAA
~15 g protein~ 7 g EAA
specifically Leucine
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mTORC1RaptorRagulatorRag A/B
Rag C/DRheb
TSC2 REDD1
Akt
GATOR1
GATOR2Sestrin2
eIF4E‐BP1
rpS6
Muscle protein synthesis
eIF4F
Amino acids(leucine)
Growth hormones(insulin)
Energy(glucose)
TSC1
AMPK
AMPK
Stress(exercise)
S6K1
eEF2
eEF2K
GTP
GTP
GDP
“inhibitor”
“activator”
“regulator”
Regulation of Muscle Protein Synthesis
insulin leucine
mTOR
protein synthesis
Diet Controls Muscle Metabolism
Plateau of muscle protein synthesis(22 yr old subjects)
Moore et al. Am J Clin Nutr 2009; 89:161
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Mealresponseforadultmuscleproteinsynthesis:
0
5
10
15
20
25
30
35
40
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Response to leucine content of meal
Leucine (g)
Protein (g) 10 20 30 40 50 60
protein synthesis
“meal threshold”
Meal Patterns:
Breakfast ~10 g protein
Lunch ~20 g
protein
Dinner ~60 g protein
Unbalanced Protein Distribution
Breakfast ~30 g protein
Lunch ~30 g
protein
Dinner ~30 g protein
Balanced Protein Distribution
Maximum Protein Synthesis
Mamerow et al. J Nutr 144: 876, 2014
Balanced Unbalanced
Recommendations:• 30 g of protein per meal• 2.5 g of leucine per meal• 1.2 ‐ 1.5 g protein/kg/day
JAMDA 14:542, 2013
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Leucine content of proteinsProtein source Leucine (%)
whey isolate 11 – 12
milk protein 9.5
egg white 8.8
“meats” 8.6
soy protein 7.8
oat protein 7.8
wheat gluten 6.8
Protein Quality:
*
*meats = 8 g protein/ozfish = 5 g protein/oz
Metabolic Roles of Leucine and BCAAs
• stimulates mTOR and muscle protein synthesis
• stabilizes blood glucose with recycling of alanine
• enhances fatty acid oxidation thru CPT‐1
• anaplerotic maintenance of TCA cycle
• enhances innate immunity thru glutamine production
• enhances vascular function thru arginine production
acetyl‐CoA
leucine mTOR Protein synthesis
Fatty acids
succinyl‐CoA
alpha‐KG
Val & Ile
glucose pyruvate
alanineglutamate
PDH
BCKAD
BCATalpha‐KIC
CPT‐1
TCAcycle
‐NH3
acyl‐CoA
‐NH3 ‐NH3
Asp
glutamine
arginine
Leucine Metabolism in Skeletal Muscle
‐NH3
mitochondria
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acetyl‐CoA
[Leucine] mTOR Protein synthesis
BCKAD
BCATalpha‐KIC
TCAcycle
‐NH3
Leucine Metabolism in Skeletal Muscle
mitochondria
[ATP]
acetyl‐CoA
leucine mTOR Protein synthesis
glucose pyruvate
alanine
PDH
BCKAD
BCATalpha‐KIC
TCAcycle
‐NH3
‐NH3
Leucine Metabolism in Skeletal Muscle
mitochondria
acetyl‐CoA
leucine mTOR Protein synthesis
Fatty acids
glucose pyruvate
alanine
PDH
BCKAD
BCATalpha‐KIC
CPT‐1
TCAcycle
‐NH3
acyl‐CoA
‐NH3
Leucine Metabolism in Skeletal Muscle
mitochondria
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acetyl‐CoA
leucine mTOR Protein synthesis
Fatty acids
alpha‐KG
glucose pyruvate
alanineglutamate
PDH
BCKAD
BCATalpha‐KIC
CPT‐1
TCAcycle
‐NH3
acyl‐CoA
‐NH3 ‐NH3
Asp
glutamine
arginine
Leucine Metabolism in Skeletal Muscle
‐NH3
mitochondria
‐NH3
acetyl‐CoA
leucine mTOR Protein synthesis
Fatty acids
succinyl‐CoA
alpha‐KG
Val & Ile
glucose pyruvate
alanineglutamate
PDH
BCKAD
BCATalpha‐KIC
CPT‐1
TCAcycle
‐NH3
acyl‐CoA
‐NH3 ‐NH3
Asp
glutamine
arginine
Leucine Metabolism in Skeletal Muscle
‐NH3
mitochondria
DietaryReferenceIntake
AcceptableMacronutrientDistributionRange
(Leucine: minimum vs optimum)
2 g
8‐9 g
> 35 g
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Protein and Exercise (athletes)
Protein for athletes
1.2 up to 2.0 g/kg body weight
Exercise improves efficiency
The “Western Diet”
Is Protein Safe?
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2009;9:311
Nature Reviews Endocrin 2014;10:723
Isn’t protein bad for your kidneys?
Protein enhances kidney functionand efficiency.
Safety of Dietary Protein
Isn’t protein bad for you bones?
Protein is the foundation of bone matrix and essential for bone repair and remodeling.
Solid Bone Matrix
Weakened Bone Matrix
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Doesn’t protein cause cancer?
WhyistheresomuchFakeNewsaboutNutrition?
IJO 39: 1109, 2015
Epidemiology: provides statistical correlations
Correlations do not equal Causation
Surveys in error by ~800 kcal/day
Carbohydrates:The Good, the Bad, and the Ugly!
• sugar• fructose• whole grains• lactose• fiber• starch• VLCD
Glucose (sugar) is an essential fuel …… but glucose can be toxic to cells (diabetes)
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DietaryReferenceIntake(carbohydrates)
C
130 g/day 65% kcal
RDA =5 servings of vegetables2‐3 servings of fruit3 servings of grains (15 g each)
Acceptable range
>300 g/d
Carbohydrate needs …
… or tolerance
RDA = 130 g/dayaverage U.S. intake ~ 300 g/day
Glucose as a fuel for muscle: exercise
Factors are: intensity duration training
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Carbohydrate Tolerance (designing diets)
RDA = 130 g/day RDA meets all nutrition needs(veggies, fruit, fiber, whole grains)
Carbs > 130 g/day are earned with exercise~60 g/hr intense Ex; HR > 100
Meal threshold < 40 g/meal; minimizes insulin response
Meals > 40 g associated with exercise recovery
Designing Diets:
Designing Diets:
• Diets with higher protein & reduced Carbs are beneficial
• Optimal protein to protect muscle & stimulatemetabolism should be 1.2 to 1.5 g/kg (100 to 140 g/day)
• Evidence supports meal distribution with ~30 g/meal
• The first meal is important for muscle response
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Designing Diets: carbohydrates?
• Balance protein and carbohydrates at every mealapproximately 1:1 ratio
• Meal with more than 40 g of Carbs have large insulin response(restrict early meals to < 40 g of Carbs)
Email: dlayman@illinois.edu
Twitter: @donlayman
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