Researcher Gladys Block, PhD and Professor of Epidemiology and Public Health Nutrition at the University of California, Berkeley, discovered that at least 30 percent of the total calorie intake of Americans surveyed was from sweets, desserts, salty snacks, fruit flavored drinks and alcoholic beverages. (l)
The end result! Junk food provides calories but not vitamins and minerals your body is in need of... in other words "empty calories."
(1) UC Berkeley Press Release by Sarah Yang, June 1, 2004