The Global Syndemic of Obesity, Undernutrition,

and Climate Change: Systems and Drivers

Undernutrition

Climate Change

Obesity

Swinburn B et al. Lancet 2019; 393:791

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Strategies to Address the Global

Syndemic of Obesity, Undernutrition,

and Climate Change

William H. Dietz MD, PhD

Sumner M. Redstone Global Center

For Prevention and Wellness

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bdietz@gwu.edu

Changes in Surface Temperature 1850-2017

GHG Generation (CO₂ Eq)

Source US Global

Agriculture. 10% 20-25%

Fossil fuels 30% 10%

Food waste 8% 8%

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Haines A, Ebi K. NEJM 2019; 380:263

The Global Burden of Obesity, Undernutrition, and Climate Change

Obesity

2 billion people worldwide

$2 trillion/year

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Diabetes

422 million people worldwide

$1.3 Trillion/year

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Stunting

155 million children with stunting

815 million people with chronic undernutrition

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Malnutrition in all its forms

$3.5 trillion/year

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Climate change

5-10% world’s GDP

The Global Syndemic(s) of Obesity, Undernutrition, �and Climate Change�

Swinburn B et al. Lancet 2019; 393:791

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• The pandemics of obesity, undernutrition and effects of climate change cluster within populations
• All three pandemics interact at both biological and biosocial levels and have adverse impacts on each other
• Large scale social forces foster clustering, and have a disparate impact on marginalized populations

Mendenhall E and Singer M,

Curr Opinion HIV and AIDS 2020; 15:213

Examples of Interactions

• Obesity, stunting, and food and nutrition insecurity in the same children and same population in LMICs
• Beef production, CH₄ and N₂O emissions, red and processed meat consumption and obesity, diabetes, colon cancer and cvd
• Increased GHGs from HICs reduce crop yields and micronutrient content of crops which contribute to food insecurity and undernutrition in LMICs

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Impact of Climate Change on Food and Nutrition Security and Undernutrition

Increased Greenhouse Gases

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7% increase in water vapor per

1 degree ⁰C increase in air temperature

Increased rainfall variability

Extreme weather

Increased CO₂

Ocean temperature rise

Ocean acidification

Food and Nutrition Insecurity

Undernutrition

Reduced crop yields

Reduced nutrient content

Price increases

Altered fish catch

Altered nutrient content

Myers SS et al. Ann Rev Public Health 2017; 38:259

N₂O from fertilizer increases GHGs Environmental degradation

Beef and dairy generate CH₄

Obesity

Diabetes

CVD

Colon cancer

Ultra-processed food

Contributions of the Agricultural and Food Processing Systems to the Global Syndemic

Drivers: Cultural norms, supply/demand, subsidies for commodity crops, price supports, political power, policy inertia

Healthier diets for

obesity, diabetes and cancer prevention

Improved nutritional quality and food security

Lower GHGs from agriculture and cattle production

Increase plant-based foods and reduce beef consumption: include externalities in the costs of food; redirect subsidies for commodity crops; communication campaigns

Obesity

Undernutrition

Climate Change

Triple Duty Actions

Contributions of Urban Design, Land Use and Transport Systems to the Global Syndemic

Transport & Urbanization

Physical Inactivity

Obesity

Climate Change

Drivers: Structural racism impacts

employment distribution, neighborhood design; cheap fuel supported by fossil fuel lobby and subsidies sustain car use

Increased physical activity, less sedentary time

Cheaper transport, access to healthy food and employment

Lower GHGs from motorized transport

Modal shifts in transport: address structural racism – connect jobs to people; redesign infrastructure to support physical and public transport systems; increase gasoline tax

Obesity

Undernutrition

Climate Change

Triple Duty Action

The Issue Is Not What to Do But How To Do It

Build political will

Initial focus on what we can personally change

Change our institutions – small p policies

Develop common targets and local coalitions

Large P policies

• Municipal policies
• Connect with state advocates
• Lobby federal representatives

Actions for Cities and Municipalities

• Invest in infrastructure for physically active transport
• Build urban food systems for resilience, health, equity and environmental sustainability
• Join international networks of cities to share resources and innovative strategies
• Nurture community coalitions to foster grass roots change and advocate for supportive national polices

Actions for National Governments

• Reduce the influence of commercial interests in policy development and increase the roles for civil society
• Re-orient business models for people, the planet, and profits (reduce externalities, redirect subsidies)
• Provide clear information on the health and environmental effects of products to consumers
• Develop metrics to monitor progress and accountability systems

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Hope Despair