First of all national security will be at a risk if we will not have enough fit men to recruit – especially if a major war broke out. Problems as such have been apparent in USA – http://www.telegraph.co.uk/news/worldnews/northamerica/usa/7632462/Obesity-among-US-schoolchildren-a-risk-to-national-security.html
Secondly a lot of money would be saved from all the pointless TV adverts, expensive hospital treatments for problems which could be PREVENTED.
If people were healthier, more likely more would chose to walk to where they need rather than use buses to go a few stops (or whichever other transport).
Lastly by not being fat we would save the earth from unnecessary pollution – for instance an overweight person would weigh the car down more than a fit person, therefore he would use up more petrol to get to where he needs – killing the earth unnecessary. Also imagine the savings if as much food wasn't consumed, less packaging, less transporting. W
Save the earth, lose weight!
For all that we know we could reverse global warming!