This book aims to engage \"Young Science - Talented & Ambitious\" for a lasting collaboration to advance holistic mathematical modeling of \"how the body works\" in variant surroundings. The book sets road signs to mathematics in body\'s vital, physical, and cognitive functions, as well as to factors of health impact in person\'s environmental and social settings. It showcases selected current research in mathematical and biological theory, mathematical models at molecular, organism, and population levels as well as engineering, imaging, and data sciences methodologies, including bio-informatics and machine learning applications. For overarching theory, evaluation of surrogate structures with category theory, multi-scale whole-body dynamics by separation of functional organization from cellular material as well as mathematical axioms matching classic principles of philosophy in traditional Chinese medicine are introduced. Interested are systems-oriented researchers in all sciences related to human health who seek new profile-shaping challenges in transdisciplinary collaboration.