Changing food consumption patterns/Dietary energy balance

Illustrative indicator: Prevalence of overweight and obesity

Yves Martin-Prével & Agnès Gartner

UMR 204 ‘Nutripass’

Metrics of Sustainable Diets and Food Systems – Expert Workshop

2Metrics of Sustainable Diets and Food Systems – Expert Workshop November 4-5, 2014

Outline

• Why do we care about overweight/obesity?

• How do we assess overweight/obesity?

• Where do we find data on overweight/obesity?

Metrics of Sustainable Diets and Food Systems – Expert Workshop November 4-5, 2014

Why do we care about overweight/obesity?

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Because overweight/obesity:• Is globally the 1st risk factor associated to mortality• Accounts for (among others):

• 44% of the global burden of diabetes• 23% of the global burden of ischemic heart diseases• 7-41% of the global burden of some cancers

(++ colorectal cancer)• Has been growing very rapidly over the past 30

years, firstly in developed countries, then in middle-income countries, now in low-income countries

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Overweight/obesity: - at the centre of chronic diseases models- but not related to the food system only

Dietary energy balance

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Total adults: 1,000,000,000 overweight+ 500,000,000 obese

(+ 43,000,000 overweight children <5y)

Metrics of Sustainable Diets and Food Systems – Expert Workshop November 4-5, 2014

How do we assess overweight/obesity?

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Body Mass Index (BMI):

BMI (kg/m²) =

weight (kg) / height (m) ²

The same index defines both under-and over- weight

The same thresholdsapply for all adults(≥20y)

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Body Mass Index (BMI):

BMI is a crude measure of corpulence meant to represent a condition of excess fat

BMI (kg/m²) =

weight (kg) / height (m) ²Age

Gender

Body shapeEthnicgroup

Physical activity

Body composition

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BMI cut-off points

Asianpopulations

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BMI has a poor individual predictive value

Same BMI different adiposity levels different health risksBecause of:

-Different ethnic groups-Different body shapes-Different physical activity levels-Different places for excess fat in the body

Metrics of Sustainable Diets and Food Systems – Expert Workshop November 4-5, 2014

Where do we find data on overweight/obesity?

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Data sources• Population-level surveillance

• Repeated cross-sectional surveys• Some middle- and high-income countries

• Demographic and Health Surveys (and others)• Preschool age children + mothers• All women of reproductive age (and sometimes men)• Middle- and low-income countries

• Self-reported data

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WHO Global data base

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Data trends and analysis• Mainly model-based estimates• Some differences between data published by WHO

and by IHME (Institute of Health Metrics and Evaluation)

Metrics of Sustainable Diets and Food Systems – Expert Workshop November 4-5, 2014

Thank you for your attention