fast food it the main cause of obesity 的论据 什么都要，多益善

Fast Food and Obesity—Is There a Connection?

Consumption of fast food by children increased dramatically from 1970 to the mid-1990s—it箂 estimated that children now get 10 percent of their total energy intake from fast foods, compared to 2 percent in the late 1970s. That's in part because the number of fast-food restaurants more than doubled between 1972 and 1995, and massive advertising campaigns were aimed at children and their parents. But it's also because fast food pervades virtually every segment of society, including public schools and hospitals, according to Harvard School of Public Health researchers who set out to learn whether the rapid recent rise in fast-food consumption is linked to the current epidemic of childhood and adolescent obesity.

To begin with, they noted, several dietary factors that are inherent in fast foods are known to cause excessive weight gains—massive portion sizes, for example, and high energy density; palatability (ap