According to the Centers for Disease Control and Prevention (CDC), obesity in the U.S. population increased from about 12% in 1991 to about 34% in 2006. The highest increase occurred in 18- to 29-year-olds. Although part of the reason is our increasingly sedentary lifestyle, the principal cause is our overconsumption of abundant processed food products, many of which are high in fat and sugar content. Why do you think fat tastes good to so many people, and is difficult to resist? Consider the fact that our appetites and digestive systems evolved over time under very different circumstances. Are there advantages to our tendency to eat too much that would have been selected for in the course of human evolution? How can we, as a society, deal with the problem?