Table 2.

Data extracted from included studies

Study overview

Aim(s)  Study design  Study year(s)  Description of country where the study was conducted  Season of the year  Setting (i.e., home/school)

Methods

Recruitment method  Inclusion criteria (main study—not urine specific)  Specific exclusion criteria (main study—not urine specific)  Data collection overview

24-h urine collection protocol

24-h urine protocol description  Criteria for completeness of urine samples   - Time of collection (hours)   - Volume of collection   - Creatinine cut-off   - Number of missed collections reported by child/parent  Specific exclusion criteria for urine samples  Adjustment for collection time/normalised?  Other nutrients analysed

Participant characteristics

Total no. participating  No. exclusions  No. withdrawals  Final n included in analyses  % male participants  Total no. urine samples  Age, mean and range  Weight category/BMI  Race/ethnicity  SES (include description of SES definition)

Results

Urine volume (L/24 h)—mean, SD/SEM, median, range  Creatinine—mean, SD/SEM, median, range