The feasibility, validity and reliability of a modified 24-hour multiple pass dietary recall to assess fruit and vegetable intake in New Zealand children : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand

Abstract

Background Adequate intake of fruits and vegetables (F/V) is crucial for children’s growth, development, and health. Despite this, many New Zealand children do not meet recommended F/V intake levels. The validity and reliability of a modified 24-hour multiple pass recall (MPR) and alternative tools such as the Veggie Meter® (VM®) for measuring skin-carotenoid scores (SCS) as a biomarker of F/V intake in children remain unexplored. Aims To establish the feasibility, validity and reliability of the modified 24-hour MPR for the evaluation of carotenoid and fruit and vegetable intake against weighed food diaries in 9 to 13–year–old school children living in Auckland. To estimate the reliability of the VM® as a tool to measure chronic skin carotenoid levels. Methods Thirty-two children (20 boys, 12 girls) participated in this study. Over a one-to-three week period, F/V intake was assessed using a modified 24-hour MPR (child-reported, weighed food diaries (parent-reported), and SCS measured by the VM®. Validity was evaluated by comparing the modified 24-hour MPR to weighed food diaries as the criterion. Reliability of the modified 24-hour MPR F/V servings were determined from raw arithmetic difference, while reliability of the modified 24-hour MPR carotenoid intake (μg/d) was expressed as a ratio. Inter-day reliability of the modified 24-hour MPR and the VM® SCS reliability were estimated using various metrics. Results Children did not meet recommended F/V intake levels based on both the modified 24-hour MPR (1.31 fruit serves; 2.00 vegetable serves) and weighed food diaries (1.26 fruit serves; 1.87 vegetable serves). Boys had higher F/V and carotenoid intakes, while girls had slightly higher SCS. The modified 24-hour MPR demonstrated significant bias and poor reliability for estimating F/V and carotenoid intake. In contrast, the VM® showed good reliability with low variability and excellent intraclass correlation coefficient (ICC). Conclusions The modified 24-hour MPR was valid but unreliable for measuring F/V intake in New Zealand children. The VM® was found to provide a reliable measure of carotenoid intake over a chronic time.