Karen Lock and Marcus Keogh-Brown - London International ...

The challenges of measuring
health, agricultural and economic effects
of adopting healthy diet
recommendations:
Brazil and the UK
Karen Lock and Marcus Keogh-Brown,
LSHTM and Leverhulme Centre for Integrative Research in
Agriculture and Health (LCIRAH)

Authors
• Karen Lock, LSHTM & LCIRAH
• Richard D Smith, LSHTM & LCIRAH
• Alan D Dangour, LSHTM & LCIRAH
• Marcus Keogh-Brown, LSHTM & LCIRAH
• Gessuir Pigatto, Universidade Estudial Paulista Julio de
Mesquita Filho, Brazil
• Corinna Hawkes, University of Sao Paulo, Brazil
• Regina Mara Fisberg, University of Sao Paulo, Brazil
• Zaid Chalabi, LSHTM & LCIRAH
REF: Lock K, Smith RD, Dangour AD, Keogh-Brown M, Pigatto G,
Hawkes C, Fisberg RM, Chalabi Z. Lancet. 2010 Nov
13;376(9753):1699-709

Background and motivation
• Transition to diets high in saturated fat/sugar/salt causing global
public health concern in all world regions
– food consumption major modifiable risk factor for chronic disease
• Globalization of agri-food system profoundly affects production/
distribution/consumption of these commodities
• Traditional evaluation approaches consider population health OR
agriculture OR wider economic effects of food policy
AIM: to illustrate importance of inter-sectoral approaches to
evaluating agri-food policy
– Assessing health AND economic effects of adopting WHO
‘healthy diet’ recommendations in different countries linked
by agricultural trade

Case study approach
• 2 countries linked by agricultural trade:
– UK: high-income, predominantly food importing country, high
rates of chronic disease
– Brazil: middle-income, major agricultural producer and global
exporter of food products including animal food products,
population that is undergoing a rapid dietary and health
transition
• Study focuses on one aspect of a healthy diet:
– Reduced saturated fat (SF) intake and the impact on ischaemic heart
disease (IHD) risk
– Applying WHO diet guidelines of SF intake

Assessing population health impacts
of a ‘healthy diet’: methods
• Potential impacts of dietary changes on IHD modeled
using hazard ratios from recent meta‐analysis
• Using the WHO comparative risk assessment method
(used in global burden of disease study)
• Assumed dietary change adopted by whole population
immediately (i.e. no modelling of temporal transitional
effects, effects on different age groups etc)
• Health effects calculated relative to the baseline
disease burdens from WHO projections for 2010

• UK:
Population health impacts of
adopting a ‘healthy diet’: results
– reductions of 7% in Disability Adjusted Life Years
(DALYs) and 3% of premature deaths averted in
one year (equivalent to 3,270 deaths)
• Brazil:
– reductions of 3% of DALYs and 2% of premature
deaths averted in one year (equivalent to 2,800
deaths)

Limitations and assumptions: health
model
Model is simplistic (but likely to be conservative)
• Limited to IHD (not diabetes, cancers etc)
• Conducted only for adults
• Brazil estimates based on Sao Paolo data
– No national data, Sao Paulo largest city with comprehensive diet data taken
as proxy. SP survey conducted in 2003 – may underestimate current
consumption
• Did not consider +ve health impacts of substitute foods i.e. fruits
and vegetables
• No allowance for difference in saturated fatty acids found in meat
and dairy products
• Assumed dietary change would be immediate, and in all
population groups

Macro-economic impacts of a ‘healthy
diet’: methods (1)
We use Computable General Equilibrium (CGE) models
How do CGE models work?
1. System of equations to specify behaviours
of various agents within the economy
– Consumers decide what to consume and how much to
save
– Producers maximise profits
– Government collects taxes, pays benefits
2. Economic dataset of income/expenditure for a given year
(must be balanced)
3. Solved using computer algebra system to ‘force’ equilibrium
solution

CGE Modelling Process
Microconsistent benchmark data
set for single year (SAM)
Exogenous
elasticities
Calibration
(model spec.)
Calculation of
benchmark equil.
Replication
check
Policy evaluation - pairwise comparison
between counterfactual & benchmark equil.

Macro-economic impacts of a
‘healthy diet’: methods (2)
• Scenarios designed to ‘Shock’ model to reflect the
impact of healthier eating: reducing consumption of:
– all animal source foods
– meat only
– dairy only
• ‘Shocks’ impact upon model via:
– labour supply (↑ due to ↓IHD mortality)
– labour productivity (↑ due to ↓ IHD morbidity)
– domestic consumption of agricultural products (↓)
– imports/exports of agricultural products (↓)

CGE model scenarios
• ‘Shock’ model by reducing intake of saturated fats
to WHO guidelines (using 3 animal food strategies)
– Overall SF reduction of 22% (UK), 7.4% (Brazil) equates to:
• All animal source foods (ASF):
• Meat only:
• Dairy only:
33% (UK), 10.5% (Brazil) or
85% (UK), 18.2% (Brazil) or
62% (UK), 27.6% (Brazil)
• Mathematical modelling to estimate labour shocks
– Mortality reduction 3.1% (UK), 2.0% (Brazil)
– Morbidity reduction 4.4% (UK), 1.7% (Brazil)
– 2008 sick certification for IHD and stroke used for baseline
• 4 scenarios applied to the 3 animal food strategies: UK
domestic demand, Brazil domestic demand, Brazil international
(i.e. export) demand, and Brazil domestic & international demand

Percentage impact to GDP
Economic impacts of a healthy diet:
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
-0.07
-0.08
UK
Animal
Domestic
Brazil
Animal
Domestic
Brazil
Animal
Int'l
GDP Results
Brazil
Animal
Dom &
Int'l
UK Meat
Domestic
Brazil
Meat
Domestic
Brazil
Meat Int'l
• Overall UK losses greatest for dairy (£5.1bn) then meat
(£3bn), ASF absorbed
• Brazil losses greatest domestically for dairy (R$475m)
but greatest international losses for meat (R$1.4bn)
• Overall economic losses appear small, some small gains
Brazil
Meat
Dom &
Int'l
UK Dairy
Domestic
Brazil
Dairy
Domestic
Brazil
Dairy Int'l
Brazil
Dairy
Dom &
Int'l

Percentage impact on GDP by sector
Percentage impact on GDP by sector
Grains/Crops
Meat
Animal
Dairy
Textiles
Extraction
Processed food
Heavy manufacturing
Light manufacturing
Utils and construction
Other transport
Water transport
Air transport
Transp. & comms
Other services
Grains/Crops
Meat
Animal
Dairy
Textiles
Extraction
Processed food
Heavy manufacturing
Light manufacturing
Utils and construction
Other transport
Water transport
Air transport
Transp. & comms
Other services
Percentage impact on GDP by sector
Grains/Crops
Meat
Animal
Dairy
Textiles
Extraction
Processed food
Heavy manufacturing
Light manufacturing
Utils and construction
Other transport
Water transport
Air transport
Transp. & comms
Other services
1.000
0.000
-1.000
-2.000
-3.000
-4.000
-5.000
-6.000
-7.000
ASF
Economic impacts
by sector
• Smaller impact for ASF
• Intermediate ASF use by meat
• Significant employment
implications for meat/dairy
Meat
Dairy
10.000
5.000
0.000
-5.000
-10.000
-15.000
-20.000
-25.000
-30.000
-35.000
5.000
0.000
-5.000
-10.000
-15.000
-20.000
-25.000
-30.000
-35.000
UK Domestic
Brazil Domestic
Brazil International
Brazil Domestic and
International

Limitations and assumptions:
economic model
• Estimating long-term structural implications:
– impact on exports to Brazil scaled back
– what will substitute for the reduced production
and consumption of meat and dairy products?
• other foodstuffs, or other goods and services?
• will substitutes represent an equivalent domestic,
import and export profile?
• No feedback loops
– e.g where lost livelihoods are associated with
negative health impacts

Study Conclusions
Adopting a ‘healthy diet’ policy will affect both population
health and the economy
• Reductions in consumption of animal source foods in high
consuming populations is of net benefit
• Uneven distribution of benefits
– UK : high health gains vs low economic losses
– Brazil: low health gains vs high economic losses
• Policy focused on reducing all animal source foods should create
less economic impact
• Ability of sectors to shift production (livestock to crops etc.) will
influence economic impact
• Health strategies tackling diet-related NCDs must address
economic, social, environmental and health objectives

Conclusion
• Understanding impacts on both health and wealth,
and of winners and losers, critical to securing a
sustainable food policy to maximise health benefits
while minimizing risks
• Although these analyses simplistic, highlighting
health and economic affects together illustrates
need to consider systems interactions between
different policy sectors, and at different levels of
impact (local to global) in developing upstream
policies to tackle NCDs

Future challenges
Good news - do not necessarily need new ‘metrics’
• CGE now recommended tool by WHO
• Already well accepted in environment, agriculture
etc sectors
Challenges:
• Improving understanding of different method
applications – promoting intersectoral applications
• Improving data –
– both data collection and compatibility between sources
• Improving CGE methods
– Sensitivity analysis
– Refining of assumptions
– Substitution for unhealthy goods – critical
– Household split by SES
– Trade modelling
– Dynamic modelling

For info: what is a ‘healthy
diet’?
• WHO recommendations* for a ‘healthy diet’:
– 15‐30% total energy as fat; saturated fat should be
under 10% and trans fatty acids under 1%
– 55‐75% total energy as total carbohydrate; added
sugars should be under 10%
– 10‐15% total energy as protein, mainly from plants
– 400g/day of fruits and vegetables
*WHO (2003). Diet, nutrition and the prevention of chronic diseases. Report of
a Joint WHO/FAO Expert consultation. Technical Report 916: Geneva