Size of text on Metro apps

I have managed to increase the windows sizes and the DPI of text in the Desktop version of Windows 8.1

I have also made the titles 'larger' in the Metro settings but the text is awfully small. How can I increase this?

The reason for this is I am using it as a HTPC

Probably going to want to let google handle this one. However I do know that MS would prefer you use the term "Modern Apps"