1. Individuals and Populations Future Dietary Reference Intakes*
Targeting Healthy and “non-Healthy”
Individuals and Populations
Future Dietary Reference Intakes*
*EA Yetley, AJ MacFarlane,LS Greene-Finestone, C Garza, JD Ard, SA Atkinson, DM Bier, AL Carriquiry, WR Harlan D Hattis, JC King, D Krewski, DL O’Connor, RL Prentice, JV Rodricks, and GA Wells. Options for basing Dietary Reference Intakes (DRIs) on chronic disease endpoints: report from a joint US-/Canadian-sponsored working group. Am J Clin Nutr. 105:249S-285S, 2017.

2. Demographic Shift
Source: U.S. Census Bureau, 

3. Changes in the Landscape of Nutrition and Health
1988 Surgeon General’s Report
1989 Diet and Health Report
1994 How Should the RDAs be Revised?
“As problems of nutritional deficiency have diminished in the U.S., they have been replaced by problems of dietary imbalance and excess”.
Prevalence of Obesity:
1986
2010
No Data <10% %–14% %–19% %–24% %–29%

4. Stunting Rates by Region (UNICEF)

5. Challenges in Setting Future DRIs for Healthy and “non-Healthy” Individuals and Populations
Outcomes of interest are unlikely to be nutrient-specific
Absolute risks of targeted preventable conditions are not 100% in any population group
Uncertainty in magnitude of risk reduction effectiveness remains difficult to estimate
Multi-factorial nature of likely outcomes of interest

6. Growth Reference Study Prescriptive Approach:
Reference v Standard
Optimal Nutrition
Breastfed infants
Appropriate complementary feeding
Optimal Environment
No microbiological contamination
No smoking
Optimal Health Care
Immunization
Pediatric routines
Optimal
Growth

7. Parental Education (y)

8. Mothers' heights – Longitudinal studycm
8% difference in maternal length (based on Oman)
Source: WHO Multicentre Growth Reference Study Group. Enrolment and baseline characteristics in the WHO Multicentre Growth Reference Study. Acta
Paediatr Suppl 2006;450:7-15 .

9. Fathers' heights – Longitudinal studycm
7% difference expressed as delta between Oman and Norway expressed as percent of Norway’s value
Source: WHO Multicentre Growth Reference Study Group. Enrolment and baseline characteristics in the WHO Multicentre Growth Reference Study. Acta
Paediatr Suppl 2006;450:7-15 .

10. Length at Birth cm
3% difference in birth length (based on delta between India and Norway, and expressed as % of birth lengths in India
Source: WHO Multicentre Growth Reference Study Group. Enrolment and baseline characteristics in the WHO Multicentre Growth Reference Study. Acta Paediatr Suppl 2006;450:7-15 .

11. Mean Lengths from Birth to 24 Months at Each of the MGRS Sites
Age
Mean of Length (cm)
200
400
600 50 60 70 80
Brazil
Ghana
India
Norway
Oman
USA

12. Projected Adult Heights
Means (points) and standard deviations (bars) of the difference between 2 times the height of the child at two years and the mid-parental height by site.

13. Key Messages
Mid-parental height consistently explained a greater proportion of
observed variability in attained child length than either paternal or
maternal height alone
Doubling a child’s height at two years matched mid parental height when
parental stature was likeliest to reflect genetic potential and their children’s
care approximated international recommendations
Meeting international care recommendations also resulted in predicted adult
statures of the children that approximate international norms
notwithstanding shortfalls in parental heights.

14. Nutrient-environment interactions: Not New to DRI Discussions
Smoking (vitamin C)
Sun exposure (vitamin D)
Epigenetics - phenotypic flexibility
Secular trends in food supply such as:
Fibre
Salt
Omega-3 fatty acids
Fortificants
Use of dietary supplements – nutrients and natural health products

15. Key Questions To Be Addressed in Deriving DRIs for Low and Middle Income Countries/Regions
When are DRI’s for healthy populations/individuals appropriate baselines for estimating needs of unhealthy populations/ individuals?
How and when does one account for undesirable characteristics such as the occurrence of LBW, excessive energy intakes, specific morbidities, poor baseline diets, polluted environments, etc?
How and when does one consider other variables such as the non- continuous nature of human growth, simultaneous consideration of multiple factors many possibly having small effects (some synergistic; others antagonistic) on targeted outcomes?
What are impacts of irregular periods of dietary excesses and want?

16. Estimating ULs for Free Living Populations In Low and Middle Income Countries
The pathophysiology of macro- and micronutrient excesses in healthy individuals is usually understood poorly at all life stages, adding to extrapolation difficulties.
Nutrients that are deficient but required to maintain homeostatic mechanisms that counter responses to other nutrient excess(es) often are inadequately considered.