A recent study by Amanda D. Cullar and Michael E Webber from the University of Texas' Center for International Energy and Environmental Policy has found that the energy embedded in wasted food represents approximately 2% of annual energy consumption in the United States.
 
They concluded that the food wasted in the U.S. in 2007 represents a staggering approximate 2030 ± 160 trillion BTU! 

If the term "BTU" doesn't mean a lot to you (and it doesn't to me) - it's just a measurement of energy. 1 BTU =  1 055.05585 joules or 252 calories. I dug around a bit and discovered there's around 5800000 BTU in a barrel of oil; so the study's figure comes to approximately 350 million barrels of oil equivalent during 2007; give or take a bit.
 
The energy required to dispose of food waste was not included in the study but the authors point out that food scraps made up 12.4% of total municipal solid waste generated in 2006.
 
Imagine that. Environmental issues aside, with all the starving people in the world, it borders on criminal. The USA isn't alone; most other developed countries have similar food waste statistics.
 
Proponents of genetically modified (GM) crops constantly raise the issue of needing to feed millions more mouths in the decades ahead, but it seems to me we don't have a food shortage issue, but more a distribution challenge. 
 
Anyhow, back to the study. 
  
Ms. Cullar and Mr. Webber raise the very valid point of food wastage being a low hanging fruit of energy efficiency and reducing greenhouse gas emissions. It's not just the energy that goes into making food, particularly fossil fuels, but the gases it emits as it rots - carbon dioxide and methane, another potent greenhouse gas.
  
You can read the study report here.
  
Food wastage is something we can all address at home - pick up some tips for reducing food waste.