It's some way off, but one of the next updates I have planned (Dizzy's & London) will have a big focus on the national obesity rate. You'll be able to explore London outside of day trips, the state of which will be directly tied to the national rate.
There will also be a lot more content concerning the fight to save Britain's waistline, with the introduction of an anti-obesity organisation committed to battling Dizzy's, which you can either help or hinder. Successfully fattening up this organisation might be the key to reaching 100% obesity.