Recommended Dietary Allowances

David L. Gee, PhD

Central Washington University

RDA Facts

• National Academy of Sciences (NAS)– Food and Nutrition Board (FNB)(past)– Institute of Medicine (IOM)(current)

• Traditionally revised every 5 years (last traditional RDA:10th ed, 1989)

• First RDA’s formulated during WWII to adequately feed soldiers

RDA Uses

• USDA’s Thrifty Food Plan– Food Stamp Program

• School Lunch Program

• Institutional Food Services

• Women, Infant, & Children Food Supplementation Program (WIC)

RDA’s: What are they?

• allowances, not requirements– different age groups– males and females– pregnant and lactating women

• Traditionally for protein, 11 vitamins, 7 minerals– New RDA’s include CHO, FAT, exercise

RDA’s: How are they determined?

• Determine individual requirements of healthy people–Nutrient balance studies

• Measure intake and losses and nutrient markers

Figure 2-2 Nutrient Requirements Vary From Person To Person

© 2002 Wadsworth Publishing / Thomson Learning™

RDA’s: How are they determined?

• Determination of allowance– Safety factor

• individual variations

• bioavailability of different foods– Iron– Protein– folate

Figure 2-2 Nutrient Requirements Vary From Person To Person

© 2002 Wadsworth Publishing / Thomson Learning™

DRI’s: Updated version of the RDA’s

• Dietary Reference Intakes

• RDA’s: “levels of intake of essential nutrients... to be adequate to meet the known nutritional needs of practically all healthy persons.”

DRI’s differ from RDA’s

• Incorporates risk reduction for chronic diseases

• Includes essential and other food components (CHO, PRO, FAT, fiber, phytoestrogens, etc)

Components of DRI’s

• DRI Recommended Intakes– Recommended Dietary Allowance (RDA)

• well substantiated evidence

– Adequate Intake (AI)• less substantiated/controversial

Other components of DRI’s

• Estimated Average Requirement (EAR)– Useful for population studies

• Tolerable Upper Intake Level (UL)

– Side effects/toxicity may occur if consumed above this level

Dietary Reference Intakes

• 1997: Bone nutrients– Calcium, phosphorus, magnesium, vitamin D, fluoride

• 1998: B vitamins– B1, B2, B3, B6, B12, folate, pantothenate, biotin, choline

• 2000: Antioxidants– vitamin E, vitamin C, selenium, carotenoids

• 2001: Miscellaneous– vitamins A&K, iron, copper, zinc, etc...

• 2002: CHO, FAT, PRO, Fiber, Physical Activity

DRI for Calcium– released August 1997

• Calcium AI’s• 9-18 yr: 1300 mg/d

– Old RDA: 800-1200

• 19-50 yr: 1000 mg/d – Old RDA: 800

• > 50 yr: 1200 mg/d – RDA: 800

DRI’s for CHO, PRO, FAT, Fiber and Physical Activity:Controversy brewing?

• Sept. 2002• Acceptable Macronutrient Distribution Range

– AMDR

• CHO: 45-55% of Calories– 2000 USDA Dietary guidelines 60%– 2005 USDA Dietary Guidelines: not specified, choose fiber-rich fruits,

vegetables, & whole grains often

• FAT: 20-35%– 2000 USDA Dietary guidelines <30%– 2005 USDA Dietary Guidelines 20-35%– Emphasis on unsaturated fat, less saturated fat

• PRO: 10-35%– Old RDA’s 0.8gP/kgBW (about same)

DRI’s for CHO, PRO, FAT, Fiber and Physical Activity

• Dietary Fiber:25g women, 38g men– 2000 Dietary guidelines 25g/2000Cal– 2005 DG: not specified

• Exercise– Moderately intense exercise accumulated for one hour

every day– 1996 Surgeon General’s Report: 30 minutes/day– 2005 Dietary Guidelines

• > 30 min/day to reduce chronic disease risk• ~ 60 min/day to manage weight • 60-90 min/day to sustain weight loss

DRIs for CHO, FAT, PRO, FIBER, & Physical Activity

Sept. 2002

• Carbohydrates: 45-65% of Calories– Dietary Guidelines: >50-60% – DRI: < 25% from ‘added’ sugars

• Fat: 20-35% of Calories– Dietary Guidelines: <30%– Specific levels of essential fatty acids made

• Protein: 10-35% of Calories– Old RDA’s >0.8g/kgBW– Recommendations are similar

DRIs for CHO, FAT, PRO, FIBER, & Physical Activity

Sept. 2002

• Fiber– First recommendations for RDA/DRI

– Adults < 50 yrs: males 38g, females 25g

– Adults >50: males 30g, females 21g

– Past recommendations: 25-35g

• Physical Activity– First recommendations for RDA/DRI

– “Maintain cardiovascular health at a maximum level”• > 1 hr/day at moderately intense level

DRI for Calcium and Related Nutrients (Vit D, P, Mg, F)

• AI’s for Vitamin D

• 9-18 yrs: 5 ug/d (RDA: 10 ug/d)

• 19-50 yrs: 5 ug/d (RDA: 5 ug/d)

• >51 yrs: 10 ug/d (RDA: 5 ug/d)

DRI’s for B-Vitamins

• Released April 1998

• Similar for B1, B2, B3, B6

• Folic Acid–adults: 400 ug/d (180-200)

–pregnancy: 600 ug/d (400)

DRI’s for B-Vitamins

• Vitamin B-12 –2.4 ug/d (2.0 ug/d)

• now includes –Pantothenic Acid

–Biotin

–Choline

FCSN 245 Upcoming Schedule

• Tuesday, April 15– Turn in study group cards– Federal income taxes due

• April 15-18 Discussion Labs– Food Label Activity– Recording 3 day food record

• Tuesday, April 22– Exam 1– Chapters 2 (dietary guidelines, labels, RDA’s) & 4

(carbs)