Abstract
Background:
Use of short recording periods is often applied in prospective dietary surveys in order to reduce participant burden, fatigue, drop-out or misreporting. It is also assumed that a shorter recording period may help optimize initial participation because of the lower burden.
Objective:
To investigate the impact of recording length on reporting status, expressed as the ratio between energy intake and calculated basal metabolic rate (EI/BMR), the percentage of consumers of selected food items and the number reported food items per meal and eating occasions per day.
Methods:
Data from two different population samples were used for comparison. In total 138 adult volunteers (68 men and 70 women aged 20-59 years) recruited within the Copenhagen area and 2504 (1153 men and 1351 women aged 20-59 y) randomly selected adults from the Danish Civil Registration System, whom participated in a validation study and the Danish National Survey of Dietary Habits and Physical Activity 2000-2002, respectively. Both studies had a cross-sectional design. Volunteers and participants completed a pre-coded food diary every day for 7 consecutive days. BMR was predicted from equations.
Results:
In the validation study, EI/BMR was significantly lower on 1st, 2nd and 3rd consecutive recording days compared to 4-7 recording days (P <0.032). The same results were seen in the Danish National Survey except that only day 1-2 was lower than day 3-7 (P <0.006). The proportion of consumers of selected food items increased with the number of recording days and was minimum 10 % higher for 7 days compared to 4 days. The number of eating occasions per day and the number of reported food items per meal did not differ between 4 and 7 recording days.
Conclusion:
Reducing the recording period from 7 to 4 consecutive days did not change EI/BMR at group level. Still a study effect seemed to occur in the two population samples resulting in lower estimates of EI/BMR day 1-2. The proportion of consumers was higher with a 7-day recording. These results support a reporting period from 4-7 days.
| Original language | English |
|---|---|
| Title of host publication | 7th International Conference on Diet and Activity Methods : Diet and Physical Activity Assessment: From the Individual to the Environment |
| Number of pages | 370 |
| Publisher | U.S. National Cancer Institute |
| Publication date | 2009 |
| Publication status | Published - 2009 |
| Event | 7th International Conference on Diet and Activity Methods: Diet and Physical Acitvity Assessment: From the Individual to the Environment - Washington DC, United States Duration: 4 Jun 2009 → 7 Jun 2009 Conference number: 7 |
Conference
| Conference | 7th International Conference on Diet and Activity Methods |
|---|---|
| Number | 7 |
| Country/Territory | United States |
| City | Washington DC |
| Period | 04/06/2009 → 07/06/2009 |