1 / 16

Metrological issues for food consumption data.

Metrological issues for food consumption data. Max Feinberg INRA. Mét@risk feinberg@inapg.inra.fr. Using nutritional measurements to study the potential link between nutrition and disease and find methods to prevent the disease. The best the measurements, the best the decisions….

kaveri
Télécharger la présentation

Metrological issues for food consumption data.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Metrological issues for food consumption data. Max FeinbergINRA. Mét@riskfeinberg@inapg.inra.fr

  2. Using nutritional measurements to study the potential link between nutrition and disease and find methods to prevent the disease. • The best the measurements, the best the decisions… Nutritional epidemiology

  3. Exposures = ai  A  Foods Weights pi Consumptions Contents qj  Consumers cij Foods i : individual (household)j : food (group) General nutritional measurement

  4. Foods Weights pi Consumptions Consumers cij Consumption measurement

  5. 24-hour Recall (24R) • Attempt to define and quantify food intake during a specific day. • Dietary Records (DRs) • Detailed descriptions of types and amounts of foods and beverages consumed, meal by meal, over a prescribed period (3-7 days). • Food Frequency Questionnaires (FFQ) • Long-term diet over months or years, not just a few days. • Household Budget Survey (HBS) • Estimation of the average consumption of a population based on point estimates of food consumptions. • Total Diet Study (TDS) • Estimation of consumer exposure to contaminants based on the analysis of foods « as consumed ». • … Consumption measurements (2)

  6. Individualconsumptionscij Weights pi Householdconsumptionsmkj Direct methods Purchasing panels Degradation ?? i : individualsk :householdsj : foods Consumptionshj National budget Survey reduction

  7. Uncertainty and variability A proposal to evaluate nutritional measurement quality

  8. Metrology: field of knowledge concerned with measurement. • Metrology includes all theoretical and practical aspects of measurement, whichever the measurement uncertainty and field of application. • Measurand: quantity intended to be measured. • Uncertainty (of measurement): parameter that characterizes the dispersion of the quantity values that are being attributed to a measurand, based on the information used. International Vocabulary of Metrology

  9. ReportedValue Y True Value T + Y T + Measurandy 95% of replicates in the interval Does this interval representuncertainty? Analogy with chemical measurement

  10. Milieu Method Manpower Instrument Material Method Environment Personnel Calibration Result +Uncertainty Traceability Samples handling Equipment Sampling Sources of uncertainty in analysis

  11. B1 Day 1 Day 1 B2 Day 2 + yij + B1 B3 B2 B3 Day 3 + Day 3 + Standard deviation of:reproducibility Day 2 Vary sources of uncertainty

  12. ReportedValue Composed standard uncertainty True Value + Y T Expanded uncertainty U = kuc(Y) p = 95% k = 2 p = 99% k = 3 95% of the future measurements Measurand Standard and expanded uncertainty

  13. Instrument Milieu Individual Material Food Naming Age,Social category, … Grouping Culture ? Weight Size Competence Location Duration Selection Inquirer Panel Study Method Manpower Grouping Measurement +Uncertainty Uncertainty sources for nutritional measurements

  14. Use multivariate techniques to identify consumption systems Consumptionsystem Consumptionpattern Variability = + Individual + Uncertainty Consumption pattern

  15. Simulated consumption systems

  16. Needs for harmonisation. • Data collection procedures. • Data evaluation. • Identification of bias. • How far are methods complementary? • A proposal:use uncertainty-variability approach to organise harmonisation. • A new discipline: “Consumetrics” ? Conclusions

More Related