READ THE NY TIMES ARTICLE: "THE EXTRAORDINARY SCIENCE OF ADDICTIVE JUNK FOOD"
It talks about how the food industry is deliberately adding sugar, salt and fat to our foods to get people "hooked on foods that are convenient and inexpensive."http://www.nytimes.com/2013/02/24/magazine/the-extraordinary-science-of-junk-food.html?ref=magazine&_r=0