title: Adaptation of Locally Available Portion Sizes for Food Frequency Questionnaires in Nutritional Epidemiological Studies: How Much Difference does it Make?
abstract: BACKGROUND
  There is need for employing strategies to minimize measurement errors while administering semi-quantitative FFQ. The current study was planned to adapt and standardize locally available portion sizes for semi-quantitative FFQ to improve its validity and document the process of standardization of portion sizes.
  
  
  METHODS
  The study was conducted in 9 villages of the INCLEN-SOMAARTH DDESS (Demographic, Development and Environmental Surveillance Site), Palwal district, Haryana, India. The subjects in these nine villages are part of a cohort study to assess the interaction between societal and household factors with food intake and physical activity of children. Systematic utensil survey was undertaken in 3 randomly chosen households per village i.e. 27 households and the portion sizes were derived from a total of 74 serving utensils. The derived sizes were classified as small (240 ml), medium (320 ml) and large (600 ml). The semi-quantitative FFQ with locally derived portion sizes was then administered to 63 children in 6-12 year age group.
  
  
  RESULTS
  The volume of food measured by the reference portion sizes generally being employed in the national surveys, would have been underestimated the food consumed by the child by 55-60% as compared to what was being consumed by the children in the study area. The correlation between food intake assessed by 24-hr recall method and FFQ using derived (local) portion sizes was better as compared to that obtained with the semi-quantitative FFQ done with reference portions.
  
  
  CONCLUSIONS
  In conclusion, local portion size adaptation of FFQ for semi-quantification is useful to mitigate measurement errors associated with this technique.
authors.affiliation: Department of Food and Nutrition, Institute of Home Economics, University of Delhi, New Delhi, India.
authors.forename: Neha
authors.initials: N
authors.lastname: Gupta
authors.affiliation: The INCLEN Trust International, New Delhi, India.
authors.forename: Sonika
authors.initials: S
authors.lastname: Verma
authors.affiliation: The INCLEN Trust International, New Delhi, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Singh
authors.affiliation: Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Tandon
authors.affiliation: Department of Food and Nutrition, Institute of Home Economics, University of Delhi, New Delhi, India.
authors.forename: Seema
authors.initials: S
authors.lastname: Puri
authors.affiliation: The INCLEN Trust International, New Delhi, India.
authors.forename: Narendra Kumar
authors.initials: NK
authors.lastname: Arora
keywords: Local portion sizes; measurement error; nutrition epidemiology; semi-quantitative food frequency questionnaire (Sq FFQ)