Exercise bikes in restaurants or the work place

  Basically, society is getting more obese. My idea is if you put exercise bikes in restaurants and the work place. People could be using these and do two things.
1. They will be burning the fats they eat.
2. They could help power the restaurant.
  If people are burning what they eat they can get fat. We are running out of fossil fuels and whilst the people are peddling away they will be burning fat and be powering the restaurant. If you have seen back to the future 2 then it is in one of the scenes.