what makes a healthy diet a healthy diet
TRANSCRIPT
What makes a healthy diet a healthy diet?Challenges and opportunities for defining, measuring, and evaluating the health impact of diet at the population level
Ashkan Afshin, MD MPH MSc ScD November 15, 2016Acting Assistant Professor of Global Health
Policy Formulation
PolicyAdoption
Policy Implementation
Policy Evaluation
Agenda Setting1. Defining optimal nutrition
2. Quantifying the burden of disease due to malnutrition
3. Evaluating the effectiveness of policies to improve nutrition
4. Evaluating the cost-effectiveness of nutrition policies
5. Evaluating the political/legal feasibility of nutrition policies
6. Evaluating the intensity of implementation of nutrition policies
7. Evaluating the short/long term effects of nutrition policies
Policy Formulation
PolicyAdoption
Policy Implementation
Policy Evaluation
Agenda Setting1. Defining optimal nutrition
2. Quantifying the burden of disease due to malnutrition
3. Evaluating the effectiveness of policies to improve nutrition
4. Evaluating the cost-effectiveness of nutrition policies
5. Evaluating the political/legal feasibility of nutrition policies
6. Evaluating the intensity of implementation of nutrition policies
7. Evaluating the short/long term effects of nutrition policies
4
Malnutrition
5
GBD 2015
1943 1992 2005 2011
1989 2002 2015
Nutrients Foods Dietary patterns
Biological mechanism No biological knowledge Intercorrelations not a problemStatistical Power No food composition data needed Between-food interactionsSupplementation Use in dietary advice
Defining diet
7
Absolute Intake
Relative IntakeHealth outcomeDisease endpoints(CVD, diabetes, cancer)
Intermediate outcomes(obesity, blood pressure)
8
Evidence Description
RCTs of disease endpoint Number of independent RCTs evaluating the effect of the risk on the disease endpoint
% of independent RCTs showing significant effect in the opposite direction
% of independent RCTs showing no effect
Prospective observational studies of disease endpoint
Number of independent prospective observational studies evaluating the association of the risk with the disease endpoint
% of independent prospective observational studies with significant association in the opposite direction
Strength Lower Limit of RR in observational studies> 1.5 (Yes/No)
Dose response Evidence of the dose-response relationship between the risk and the outcome(Yes/No)
Biologic plausibility Potential biologic mechanism that could explain the effect of the risk on the disease endpoint (Yes/No)
Analogy Evidence on the relationship between the risk factor and a disease endpoint from the same category (Yes/No)
Outcome RCTs
(Num
ber)
RCTs
with
sign
ifica
nt e
ffect
in
the
oppo
site
dire
ctio
n (%
)
RCTs
with
nul
l fin
ding
s (%
)
Pros
pect
ive
obse
rvat
iona
l st
udie
s (Nu
mbe
r)
Pros
pect
ive
obse
rvat
iona
l st
udie
s with
sign
ifica
nt
Low
er li
mit
of R
R >
1.5
Dose
-res
pons
e re
latio
nshi
p
Biol
ogic
pla
usib
ility
Anal
ogy
Lip and oral cavity cancer 0 - - 2 0
Nasopharynx cancer 0 - - 2 0
Other pharynx cancer 0 - - 2 0
Larynx cancer 0 - - 2 0
Oesophageal cancer 0 - - 5 0
Tracheal, bronchus, and lung cancer 0 - - 22 0
Ischaemic heart disease 0 - - 9 0
Ischaemic stroke 0 - - 9 0
Hemorrhagic stroke 0 - - 5 0
Diabetes mellitus 0 - - 9 0
Oesophageal cancer 0 - - 5 0
Ischaemic heart disease 0 - - 9 0
Ischaemic stroke 0 - - 8 0
Hemorrhagic stroke 0 - - 5 0
Ischaemic heart disease 0 - - 7 0
Ischemic stroke 0 - - 6 0
Hemorrhagic stroke 0 - - 6 0
Diabetes mellitus 0 - - 10 0
Diet low in nuts and seeds Ischaemic heart disease 1 0 100 6 0
Diabetes mellitus 1 0 100 5 0
Risk
Diet low in vegetablesDiet low in vegetablesDiet low in vegetablesDiet low in whole grains
Diet low in whole grains
Diet low in nuts and seeds
Diet low in fruits
Diet low in fruitsDiet low in fruitsDiet low in fruitsDiet low in fruits
Diet low in vegetablesDiet low in fruits
Diet low in fruits
Diet low in fruitsDiet low in fruitsDiet low in fruits
Diet low in whole grainsDiet low in whole grains
Epidemiologic evidence supporting causality between dietary risk-outcome pairs
GBD 2015
Outcome RCTs
(Num
ber)
RCTs
with
sign
ifica
nt e
ffect
in
the
oppo
site
dire
ctio
n (%
)
RCTs
with
nul
l fin
ding
s (%
)
Pros
pect
ive
obse
rvat
iona
l st
udie
s (Nu
mbe
r)
Pros
pect
ive
obse
rvat
iona
l st
udie
s with
sign
ifica
nt
Low
er li
mit
of R
R >
1.5
Dose
-res
pons
e re
latio
nshi
p
Biol
ogic
pla
usib
ility
Anal
ogy
Colon and rectum cancer cancer 0 - - 7 0
Colon and rectum cancer cancer 0 - - 8 0
Diabetes mellitus 0 - - 9 11
Colon and rectum cancer cancer 0 - - 9 11
Ischaemic heart disease 0 - - 5 0
Diabetes mellitus 0 - - 8 0
Body mass index 10 0 60 22 0 - -
Colon and rectum cancer cancer 0 - - 15 0
Diet low in fibre Ischaemic heart disease 0 - - 12 0
Colon and rectum cancer cancer 0 - - 13 0
Ischaemic heart disease 17 0 94 16 0
Ischaemic heart disease 8 0 75 11 0
Ischaemic heart disease 0 - - 4 0
Systolic blood pressure 45 0 73 - - - -
Stomach cancer 0 - - 3 0
Risk
Diet low in fibre
Diet low in calcium Diet low in seafood omega-3 fatty acidsDiet low in polyunsaturated fatty acidsDiet high in trans fatty acids
Diet low in milkDiet high in red meatsDiet high in red meatsDiet high in processed meatsDiet high in processed meatsDiet high in processed meatsDiet high in sugar sweetened beverages
Diet high in sodiumDiet high in sodium
Epidemiologic evidence supporting causality between dietary risk-outcome pairs
GBD 2015
Policy Formulation
PolicyAdoption
Policy Implementation
Policy Evaluation
Agenda Setting1. Defining optimal nutrition
2. Quantifying the burden of disease due to malnutrition
3. Evaluating the effectiveness of policies to improve nutrition
4. Evaluating the cost-effectiveness of nutrition policies
5. Evaluating the political/legal feasibility of nutrition policies
6. Evaluating the intensity of implementation of nutrition policies
7. Evaluating the short/long term effects of nutrition policies
12
Com
para
tive
Ris
k A
sses
smen
t
Measurement Error
13
Subar (2001)
Publication Bias
14
Nuts & IHD
Red meat & Diabetes Processed meat & Diabetes
Trans fat & IHD
SSBs & Diabetes
Definition of dietary factors
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Wang Huang Johnsen Wu Jacobs Jensen Steffen Liuadded branadded wheat germbagelsbranbreakfast cerealsbrown ricebrown rice flourbuckwheatbulgurcooked cerealcooked oatmealcorn meal dumplingscorn meal flat cakescorn meal porridgecorn meal steamed breadnon-white breadoatsother grainspancakespizzapopcornpsyllium Aune (2016)
Covariates
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Age
Sex
Race
Educ
atio
n
Mer
ital S
tatu
s
Smok
ing
Alco
hol
Phys
ical
Exc
eris
e
Enge
ry
Frui
t and
Veg
etab
les
SFA
Fish
/ Se
afoo
d
PUFA
MU
FA
Tran
s- F
A
Red
Mea
t
Sucr
ose
Coffe
e
Sodi
um
Soy
Dairy
BMI
Wai
st/h
ip
Vita
min
Sup
plem
ents
Ora
l Con
trac
eptiv
es
HRT
Diab
etes
Hyp
erte
nsio
n
Hyp
erch
oles
tero
lem
ia
Men
tal S
tres
s
Men
opau
sal S
tatu
s
Slee
p Du
ratio
n
Atkins (2014)Eshak(2011)Eshak (2014)Jacobs(2001)Jensen(2004)Johnsen (2015)Liu (1999)Mink (2007)Muraki (2014)Muraki (2014)Pietinen (1996)Rautiainen (2012)Steffen(2003)Tognon (2014)Wang(2016)Yu (2013)
Whole grains and Ischemic Heart DiseaseAune (2016)
Correlation between dietary factors
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Veg
Frui
t
Proc
Mea
t
Red
Mea
t
Nut
s/se
eds
Who
le g
rain
s
SSB
Milk
Sodi
um
Om
ega-
3
PUFA
SFA
Fibe
r
Calc
ium
Veg 1.00Fruit 0.19 1.00Proc Meat -0.13 -0.04 1.00Red Meat -0.02 -0.11 -0.08 1.00Nuts/seeds 0.10 0.13 -0.07 -0.08 1.00Whole grains 0.08 0.17 -0.07 -0.11 0.12 1.00SSB -0.21 -0.22 0.03 0.07 -0.13 -0.18 1.00Milk -0.04 0.04 -0.02 -0.02 -0.03 0.09 -0.12 1.00Sodium 0.29 -0.12 0.31 0.08 -0.13 -0.03 -0.13 -0.05 1.00Omega-3 0.12 0.05 -0.10 -0.06 0.07 0.03 -0.07 -0.04 0.14 1.00PUFA 0.08 -0.03 0.06 -0.13 0.21 0.00 -0.15 -0.14 0.02 0.07 1.00SFA -0.14 -0.12 0.18 0.14 -0.07 -0.18 -0.14 0.10 0.00 -0.11 0.09 1.00Fiber 0.61 0.48 -0.15 -0.17 0.25 0.44 -0.34 0.04 0.07 0.05 0.04 -0.25 1.00Calcium 0.10 0.11 0.02 -0.10 0.11 0.16 -0.27 0.54 0.11 -0.02 -0.17 0.18 0.23 1.00
NHANES 2011-2012
RR for CHD per 1 serving (28.4g)/week of nuts
Afshin (AJCN, 2014)
Luo (AJCN, 2014)
Zhou (AJCN, 2014)
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Com
para
tive
Ris
k A
sses
smen
t
20
GBD 2015 Fruits 200-300 gr/dayVegetables 340-500 gr/dayWhole grains 100-150 gr/dayNuts 16-25 gr/dayRed meats 18-27 gr/dayProcessed meats 0-4 gr/dayMilk 350-520 gr/day
Sugar sweetened beverages 0-5 gr/day
Polyunsaturated fatty acids 9-13% of total daily energy
Seafood omega-3 fatty acids 200-300 mg/day
Trans fatty acids 0-1%EDietary fiber 19-28 gr/dayDietary calcium 1-1.5 gr/day
New approach to determine TMREL
Healthy diet fact sheet (WHO)
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Free sugars<10% E/d Salt <5 g/d | Sodium< 2g/d Total Fat < 30% E/d Adiposity Cardiovascular disease Cardiovascular disease
Mente (Lancet 2016)
Sodium excretion and risk of cardiovascular disease
Mozaffarian (NEJM 2014)
Sodium<5 g/d Sodium<2 g/d
Citation network graph with 269 reports and 2165
citations.
Ludovic Trinquart et al. Int. J. Epidemiol. 2016
Co-authorship network graph with 643 authors.
Ludovic Trinquart et al. Int. J. Epidemiol. 2016
Reducing intake of free sugars and body fatness Increasing intake of free sugars and body fatness
Adults
Children
Morenga (BMJ, 2012)
Isoenergetic exchanges of free sugars with other carbohydrates
Free sugars<10% E/d
Morenga (BMJ, 2012)
Total Fat< 30% E/d
Howard (2006)
28
Com
para
tive
Ris
k A
sses
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t