hummod.org - mathematical model of human physiology - uses over 5,000 variables you can play with
homphysiology.org lets you download their software written in java
Entelos PhysioLab is a mathematical physiological model of systems biology, complex simulations of disease physiology using a framework of deterministic differential equations based on empirical data in humans
I did a lot of research with Aurametrix, connecting the dots between many environmental variables such as food we eat, air we breathe, things we touch, physical activity, genome and microbiome.
I am sure there are lots of academic projects tackling various aspects of your problem. What are business goals?