Gina, the best way to preform a 24 hour recall is to find a registered dietitian. The difference between a food frequency questionnaire that is self-administered and a 24 hour recall is that a professional is needed for the later. For people to answer what they ate and drank in the past 24 hours requires the use of food models, measuring cups, standard plates and glasses, etc. Once the data is collected accurately, then it can be entered into a software package to calculate the macro and micro nutrients. Also the portions of fruits and vegetables can be estimated. Would you please specify what type of project you are doing so I can be of greater assistance?

The ASA24 is a web-based self-administered 24-h dietary recall program that is available free to researchers. http://appliedresearch.cancer.gov/tools/instruments/asa24/

I second Julia's comment. I used the ASA24 for a previous study. Fairly easy to use from a researcher's point of view. I did have some trouble with participants who had limited English proficiency (Mandarin speakers), so think about that when designing the study. Feel free to contact me about my personal experiences with the tool.