Attaching metabolic expenditures to standard occupational classification systems: perspectives from time-use research

Area of Science:

• Occupational Health and Safety
• Sociology
• Energy Metabolism

Background:

• Time-use data traditionally inform economic and sociological research.
• Emerging research utilizes time-use data to study physical activity (PA) and physical activity energy expenditure (PAEE).
• A challenge exists in accurately assigning MET values to paid work due to limited job-specific task recording in time-use surveys.

Purpose of the Study:

• To address the difficulty of assigning MET values to paid work activities within time-use surveys.
• To develop a standardized methodology for calculating occupational activity energy expenditure (PAEE) across diverse occupations.
• To enhance the utility of time-use data for detailed physical activity research.

Main Methods:

• Utilized detailed occupational status information from time-use survey questionnaires.
• Employed the 2008 International Standard Classification of Occupations (ISCO-08) manual, which lists job-specific tasks.
• Assigned MET values to job-specific tasks using the Ainsworth Compendium and calculated average MET values for each of the 436 ISCO-08 occupations.

Main Results:

• The International Standard Classification of Occupations (ISCO-08) Major Groups 'elementary occupations' and 'craft and related trades workers' exhibit significant variation in job-specific MET values.
• These two occupational categories accounted for 21.6% of the Belgian working population in 2013.
• Identified specific occupational groups requiring further investigation for detailed occupational activity analysis.

Conclusions:

• A clear, replicable procedure was established for calculating occupational activity for all ISCO-08 occupations.
• The developed methodology and calculations are provided for other researchers to use, replicate, and refine.
• This work facilitates more accurate PAEE assessments from time-use data, particularly for manual labor occupations.