I use demographic data frequently, especially, for residential condo/townhome or mixed use projects on which I work with developers but I have never seen direct data of the kind you are looking for. ESRI is very good and at times you could use US government data though do remember that it is likely to be dated and you will have to extrapolate and make projections which could increase the risk and make your results unreliable. As a developer you may have used regression analysis when applying statistical data for projections and will appreciate the risks you run.
My suggestion is to try and contact the marketing and research departments of established food and fitness chains and see if you can buy it from them.
United America Realty