Validation of an estimated food record

Abstract

Objective: To validate an estimated food record (EFR), using a weighed food record (WFR) as the reference method, for the determination of food consumption and nutrient intakes in a group of Costa Rican adults.

Design: For the WFR, all foods consumed by subjects during seven consecutive days were weighed and recorded by nutrition students. Two EFRs (a 4-day and a 3-day record) were recorded by subjects with the use of home measures and photographs to estimate amounts.

Setting: Costa Rica.

Subjects: Sixty adults: 30 men and 30 women; 30 living in urban and 30 in rural areas.

Results: The EFR gave statistically significant lower average intake estimates for energy and 12 of the 22 nutrients examined. The correlation coefficients ranged from 0.68 (polyunsaturated fats) to 0.87 (calcium). The percentage of subjects classified into the same quartile ranged from 45.0% (polyunsaturated fats) to 68.3% (vitamin B12). For all nutrients except vitamin C, 0 or 1.7% were misclassified into extreme quartiles. For food group consumption, the EFR gave statistically significant lower estimates for six of the 17 groups and correlation coefficients ranged from 0.22 (fish) to 0.93 (beverages). Greater differences in estimates of mean energy and nutrient intakes were detected among subjects from rural areas, caused in part by a tendency to underestimate the amounts of rice and beans consumed.

Conclusion: Validation of the EFR using a WFR as the reference method gave results that compare favourably with those reported by other authors, and support the use of the EFR for dietary surveys among Costa Rican adults.