Free fruit at workplace intervention increases total fruit intake: a validation study using 24 h dietary recall and urinary flavonoid excretion

Kirstine Suszkiewicz Krogholm, Lea Bredsdorff, Sevil Alinia, Tue Christensen, S.E. Rasmussen, L.O. Dragsted

Research output: Contribution to journalJournal articleResearchpeer-review


Background/Objectives: To validate 24 h dietary recall of fruit intake by measuring the total 24 h excretion of 10 different flavonoids in 24 h urine during an intervention with free fruit at workplaces. Subjects/Methods: Employees at workplaces offering a free-fruit program, consisting of daily free and easy access to fresh fruit, and controls employees at workplaces with no free-fruit program were enrolled in this validation study (n = 103). Dietary intake was assessed by using a 24 h dietary recall questionnaire at baseline and approximately 5 months later. Ten flavonoids, quercetin, isorhamnetin, tamarixetin, kaempferol, hesperetin, naringenin, eriodictyol, daidzein, genistein, and phloretin, were measured using HPLC-electrospray ionization-MS. Results: The 24 h urinary excretion of total flavonoids and the estimated intake of fruits were significantly correlated (r(s) = 0.31, P
Original languageEnglish
JournalEuropean Journal of Clinical Nutrition
Issue number10
Pages (from-to)1222-1228
Publication statusPublished - 2010


  • biomarker
  • fruit
  • validation
  • vegetables
  • 24 h dietary recall
  • flavonoids

Cite this