There's no easy way to say this, America: You're getting fatter and older every year. Over a quarter of the population is obese, and the rate of obesity increases 0.5 percent each year. The amount of folks aged 65 and up currently stands at 40 million, but that number will increase to nearly 90 million by 2050. What does any of this have to do with automobiles? A lot – if you're a safety engineer.