Why Have Americans Become More Obese?
研究了过去25年美国肥胖率上升的原因，发现主要源于卡路里摄入增加，而食品消费增长又由技术创新推动，使食物能大规模预制并降低准备时间成本。
Americans have become considerably more obese over the past 25 years. This increase is primarily the result of consuming more calories. The increase in food consumption is itself the result of technological innovations which made it possible for food to be mass prepared far from the point of consumption, and consumed with lower time costs of preparation and cleaning. Price changes are normally beneficial, but may not be if people have self-control problems. This applies to some, but not most, of the population.