When it reaches the brain, levodopa is changed into dopamine, the chemical that is lacking in people with the disease.

VOA: special.2009.04.07

The calorie density has changed because food is processed, so the calories in the fat and the sugar that can get squeezed into things made possible by technological changes has shifted things a lot.

食品经过加工,热量密度发生了变化,添加到食品中的脂肪和糖类,其卡路里含量可通过技术手段进行调整,进而造成很大不同

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选