What Is The Optimal Choice Of Days For Dietary Recording Method For Collegiate Athletes?

BACKGROUND: Dietary surveys are crucial for assessing athletes’ energy intake (EI). Dietary recording is an indispensable method for obtaining detailed information, but many uncertainties exist regarding the optimal number and characteristics of days to conduct such surveys. PURPOSE: To examine the choice of days used in implementing of dietary recording method to understand the characteristics of EI in collegiate athletes and the difference between those EI and total energy expenditure (TEE) evaluated by the doubly labeled water (DLW) method. METHODS: The subjects were 44 collegiate athletes. Dietary recording methods using a combination of weighing and photographic methods were implemented for one consecutive week during a period of maintaining body weight, and TEE was estimated using the DLW method. Subjects’ dietary records (DRs) were checked by skilled sports dietitians using food models and cards, and EI was calculated using a nutrition calculation software. We classified 308 samples of 7-day (7-d) DRs from 44 subjects according to whether they were on weekdays or weekends and whether they had training sessions (Tr) or classes (Cls); the differences between EI and TEE assessed by DLW were examined for each selected pattern. RESULTS: TEE was 2,846 ± 418 kcal/d. The coefficient of variation (CV, %) between athletes was 25% for 1-d, 15% for two days in EI for different random sampling periods for 1- to 7-d from consecutive 7-d DRs. Athletes’ CV in these was 39% on 1 d only, 33% on two days, and 31% on three days. EI on weekdays was 2,034 ± 638 kcal/d, 2,208 ± 681 kcal/d on Saturday, and 1,970 ± 734 kcal/d on Sunday, with no significant differences (p = 0.24). By contrast, a significant difference was observed in EI between the days of four patterns with or without (No) Tr and Cls (p < 0.01, Tr + Cls:2,278 ± 741 kcal/d, NoTr+Cls:2,026 ± 615 kcal/d, Tr + NoCls: 1,860 ± 742 kcal/d, NoTr + NoCls: 2,108 ± 709 kcal/d). All EI were significantly lower than TEE(p < 0.01). CONCLUSION: The choice of days to understand the characteristics of EI in collegiate athletes may be optimally implemented for three days, focusing on the presence or absence of classes. However, the fact that the EI was underestimated compared to TEE should be considered.