All participants will be asked to fill out a demographic questionnaire as well as a Food Frequency Questionnaire (FFQ), a questionnaire on variety of fruits and vegetables consumed and a 24-h-food-recall questionnaire. All questionnaires will be administered by trained interviewers. During the study period, the 24h-food recall questionnaire will be administered four more times; two times before the 4-week intervention period and two times after the intervention period. After the 4-week intervention period, interviewers will administered the FFQ and the questionnaire on variety.