Studying Microtemporal, Within-Person Processes of Diet, Physical Activity, and Related Factors Using the APPetite-Mobile-App: Feasibility, Usability, and Validation Study

Alea Ruf   ¹ , BSc, MSc ;   Elena Doris Koch   ² , BA, MA ;   Ulrich Ebner-Priemer   ^{2, 3} , BA, MA, PhD, Prof Dr ;   Monika Knopf   ⁴ , BA, MA, PhD, Prof Dr ;   Andreas Reif   ¹ , Dr med, Prof Dr ;   Silke Matura   ¹ , BA, MA, Dr rer med

¹ Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital, Goethe University, Frankfurt, Germany

² Mental mHealth Lab, Institute of Sports and Sports Science, Karlsruhe Institute of Technology, Karlsruhe, Germany

³ Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany

⁴ Department of Developmental Psychology, Goethe University, Frankfurt, Germany