Optimal Protein Intake and the Recommended Daily Allowance (RDA)

8/9/2019 Optimal Protein Intake and the Recommended Daily Allowance (RDA)

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Optimal Protein Intakeand the RDA

Presents

Seminar Highlights from the Florida DieteticsAssociation Meeting

July 13, 2010

Orlando, FL

A Presentation Provided by The HealthSpan Institute andContinuing Education


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Optimal Protein Intakeand the RDA

The Scientific Basis for the Benevia ProductPortfolio and The Need for Superior HighLeucine/Essential Amino Acid Protein Blends asProvided in all Benevia Clinical NutritionProducts.


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Optimal Protein Intake

and the RDA

Robert R. Wolfe, Ph.D.

Professor, GeriatricsUniversity of Arkansas for Medical Sciences

Jul y 13, 2010. Orlando, Florida

Florida Dietetics Association Annual Meeting


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Current Guidelines Where Do They Come From?

Institute of Medicine

Food and Nutrition Board

Dietary Reference Intake (DRIs)

EAR

Estimate

AverageRequirement

RDA

Recommend

ed DietaryAllowance

UL + LL

Upper and

LowerLimits

AMDR

Acceptable

MacronutrientDistribution

Range

USDA Dietary GuidelinesOther


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N-Balance: The Primary

Tool for Determining DRI

N-balance determines the minimalamount of protein intake needed toavoid a progressive loss of body

protein.


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Current Recommendations

EAR- 0.66 gm protein / kg x day

RDA- 0.80 gm protein / kg x day

UL + LL - No Recommendations

AMDR - 10-35% of Energy of Intake

Taken from DRIs


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Relation Between

Recommended DietaryAllowance (RDA)and

Acceptable NutrientDistribution Range


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Acceptable MacronutrientDistribution Ranges

Range (% of energy)

Macronutrient Children, 1-3 y Children, 4-18 y Adults

Fat 30-40 25-35 20-35n-6 polyunsaturated fats

(linoleic acid)5-10 5-10 5-10

n-3 polyunsaturated fats*(-linolenic acid)

0.6-1.2 0.6-1.2 0.6-1.2

Carbohydrate 45-65 45-65 45-65Protein 5-20 10-30 10-35

SOURCE: IOM (2002a).


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Average Energy Requirement

35 kcal / kg x dayIf protein intake =

35% = 12.25 Kcal / kg x day

= 3gm protein / kg x day

10% = 3.5 Kcal / kg x day

= 0.89 gm protein / kg x day


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The RDA is Below the

Minimal AMDR for Protein


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Implication of AMDRs:

The optimal level of protein intakeis greater than the minimal needed

to avoid deficiency.


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We Should ConsiderMinimal and Optimal Levels

of Protein Intake


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Protein Intake Greater thanMinimal Requirements

Primarily Targets Muscle


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Muscle Protein Plays aCentral Role in Whole Body

Protein Metabolism


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Fasted

AminoAcids

Gut


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AminoAcids

Gut

Fasted + Stress


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AminoAcids

Fed

Aminoacid

s

Gut


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Is Adequate Muscle Mass

Important for Health?


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Midthigh Muscle Cross-Sectional Area PredictsMortality in Patients with COPD

Marquis et al, Am J Respir Care Med, 166: 809, 2002

Click to edit Master text stylesSecond level

Third level Fourth level

Fifth level


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There is a threshold effect of

loss of muscle and severity ofstress.


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Mortality and Strength

From Ruiz RJ, et al. BMJ 2008; 337(7661):92-95.


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Older individuals are much

closer to the dangerthreshold than young people


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How Does Ingested ProteinAffect Muscle Protein?


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Muscle Protein is in a ConstantState of Turnover

AMINO ACIDS

CELL

BLOOD

AminoAcids

PROTEINS

Oxidation

SynthesisBreakdown


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Protein intake stimulates

growth of muscle protein


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Response to a Single Serving of Beef

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

Basal 4 oz Basal 12 oz

MuscleProteinS

ynthesis%/h


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Dose Response to Protein Intake

There is a maximal effective singledose response to protein intake.


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Does increased protein intake

translate to more lean massand improved healthoutcomes?


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Dietary Protein Intake and Change inLBM over 3 y in Elderly (n= 2066)

From Houston DK et al. Am J Clin Nutr 2008; 87(1):150-155.


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Changes in Nutritional Status and Patternsof Morbidity among Free-Living Persons: a

10 year longitudinal study

Vellas BJ, et al. Nutrition 1997; 13:505-519.

304 subjects, age 72 at start

Results:Subjects with protein intakes greater than 1.2 g / kg day had fewer health problems over 10 years than

those with protein intakes less than 0.8 g / kg day.


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Protein Intake and

Cardiovascular Health


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Relative Risks (RR) of IschemicHeart Disease in 80,082 Women

1 2 3 4 5

Total Protein Intake 14.7 17.1 18.8 20.6 24.0

Multivariable RR 1.0 0.86 0.84 0.91 0.72

From: Hu et al. Am J Clin Nutr 1999; 70:21-227.


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Protein Supplements (20g/day) ReduceBlood Pressure in Hypertension

-14

-12

-10

-8

-6

-4

-2

0

Systolic Pressure Diastolic Pressure

From: Townsend et al. Am J Hypertension 2004; 17:1056


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Protein Intake and Bone Health

Protein under nutrition associated with low bone mineraldensity and greater fracture risk.

Geinoz G, et al. Osteoporos Int 1993; 3:242-248.

Heany RP. Am J Clin Nutr 2002; 75:509

Protein supplementation improves outcome after hipfracture.

Bonjou JP, et al. Bone 1996; 18:139S.

Tkatch L, et al. J Am Coll Nur 1992; 11:519.

Frost HM. J Bone Min Res 1997; 12:1-9.


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Benefits of Protein Intake inWeight Management

Thermogenesis

Satiety

Partitioning of nutrients to muscle


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How Much Protein Intake is

Optimal


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Estimation of Optimal

Protein Intake from MuscleMetabolism Studies


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Optimal Protein Intake fromMetabolic Studies

Maximal stimulation of muscle protein synthesis isachieved with 15 gm EAAs (35 gm protein).

Recommended intake for 70 kg man:

35 gm protein / meal x 3 meals / day

= 105 gm protein

= 1.5gm protein / kg x day


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Optimal Intake vs RDA

RDA = 0.8 gm protein / kg x day

Recommended from Metabolic Studies

= 1.5 gm protein / kg x day


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Dietary Recommendations

Protein intake by age NHANES, 2003-2004

Dietary GuidelinesLower AMDR Upper AMDR

1.5 g/kg/d

0

5

10

15

20

25

30

35

%

Calories

2-3 4-8 9-13 14-18

19-30

31-50

51-70

71+

Years

Protein


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Conditions Which May Increase the

Optimal Level of Protein Intake

Aging

Muscle wasting (eg, cachexia, sarcopenia, etc.Acute response to injury, critical illness

Diabetes

ObesityOsteoporosis

Exercise training


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Muscle Protein Synthesis

in Cancer

pLeu

500

pIle

200


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0 30 60 90

120

150

180

210

240

270

300

0

100

200

300

400

500EXP

Control

Time (min)

M

0 30 60 90

120

150

180

210

240

270

300

0

50

100

150

200EXP

Control

Time (min)

M

pVal

0 30 60 90 120

150

180

210

240

270

300

0

100

200

300

400EXP

Control

Time (min)

M

pPhe

0 30 60 90 120

150

180

210

240

270

300

0

50

100

150EXP

Control

Time (min)

M

There was a significant interaction and group effect for leucine (P


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meanFSR%

Postab

sorptiv

eFe

d

Delta

-0.05

0.00

0.05

0.10

0.15Control

EXP

%hour

Muscle protein fractional synthetic rate. A significant interaction was found for FSR (P=0.0269.


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What About the Kidney?


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There is no evidence that higher

protein intakes cause renal failurein healthy individuals

Institute of Medicine. Dietary Reference Intakes

for Carbohydrate, Fiber, Fat, Fatty Acids,

Cholesterol, Protein, and Amino Acids.

Washington, D.C.: National Academy Press; 2005


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Lean Body Mass

Predicts Relative Risk of Death in ESRD

Lowrie and Lew, AJKD, 1990


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Effect of Dietary Protein Intake inKidney Disease (n=585)

From Levey AS, et al. Am J Kid Disease 2006; 48(6):878-888.


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Effect of ProteinIntake on Incidence

of Kidney Failure(A) and compositeof Kidney Failure

and All-CauseMortality (B)

From Levey AS, et al. Am J Kid Disease 2006; 48(6):878-888.


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Conclusion

A relatively high proportion (20% ormore of caloric intake) of protein intakebenefits muscle and other health

outcomes without significant healthrisks.

Optimal Protein Intake and the Recommended Daily Allowance (RDA)

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