Relative validity of interviewer-administered 24-hour recalls collected by telephone and in-person compared with weighed food records among rural Sri Lankan adults

Authors: JOYCE, CAROLINE - University Of California, Davis; STEWART, CHRISTINE - University Of California, Davis; ARNOLD, CHARLES - University Of California, Davis; SITISEKARA, HASARA - Wayamba University Of Sri Lanka; Caswell, Bess; HESS, SONJA - University Of California, Davis; MARGOLIES, AMY - International Food Policy Researc Institute (IFPRI); RANATUNGA, THILANKA - Wayamba University Of Sri Lanka; PERERA, THUSHANTHI - Wayamba University Of Sri Lanka; OLNEY, DEANNA - International Food Policy Researc Institute (IFPRI); SILVA, RENUKA - Wayamba University Of Sri Lanka; GELLI, AULO - International Food Policy Researc Institute (IFPRI)

Submitted to: Current Developments in Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/5/2026
Publication Date: 3/12/2026
Citation: Joyce, C.A., Stewart, C.P., Arnold, C.D., Sitisekara, H., Caswell, B.L., Hess, S.Y., Margolies, A., Ranatunga, T., Perera, T., Olney, D.K., Silva, R., Gelli, A. 2026. Relative validity of interviewer-administered 24-hour recalls collected by telephone and in-person compared with weighed food records among rural Sri Lankan adults. Current Developments in Nutrition. 10(4). https://doi.org/10.1016/j.cdnut.2026.107672.
DOI: https://doi.org/10.1016/j.cdnut.2026.107672

Interpretive Summary: The 24-hour dietary recall is a commonly-used method for collecting data on dietary intakes, but completing and analyzing these recalls can have high time, logistics and staff costs. Technological improvements can reduce such costs, but it needs to be confirmed that the data obtained are as good as those collected by older methods. We compared the accuracy and cost of conducting 24-hour dietary recalls in rural Sri Lanka by phone interview or in-person interview. We checked the quality of data from both methods against direct, weighed observation of the foods consumed. The total amount of energy consumed from foods and drinks was underestimated by both methods compared to the weighed record, mostly because respondents did not report their portion sizes accurately. For estimation of most nutrient intakes, the phone interview performed as well or better than the in-person interview. The phone interview was also less expensive to conduct.

Technical Abstract: Objective. To assess the validity and costs of phone versus in-person 24HR compared to observed weighed food records (WFR), a gold standard dietary assessment method. Methods. We used a randomized cross-over design to collect phone and in-person 24HR from 103 rural Sri Lankan adults, each matched to a WFR collected on the reference day. Agreement was assessed using equivalence testing with 15% error bounds and concordance correlation coefficients (CCC). Memory and portion size estimation errors were examined using descriptive statistics. Costs of each 24HR method were estimated using financial expenditures and micro-costing. Results. Compared to WFR, respondents underreported energy intake by 263 kcal (12.6%) in phone 24HR and 229 kcal (10.9%) in face-to-face 24HR, primarily due to portion size misestimation. Mean intakes of protein and six micronutrients were equivalent between phone and WFR. Although no nutrients were equivalent for in-person recalls, the two recall methods had relative equivalence for energy, carbohydrates, fat, zinc, and niacin. The average CCC was slightly higher for phone recalls, while memory error was lower for in-person recalls. Costs per respondent were $337 for phone 24HR and $498 for in-person 24HR. Conclusions. Among rural Sri Lankan adults, phone-based 24HR were comparable to in-person 24HR in estimating nutrient intakes, although both methods underestimated true intakes. Phone-based recalls were less expensive and performed at least as accurately as those collected face-to-face.