(NewsTarget) The invention of the microwave may have been intimately connected to the beginning of an epidemic in obesity, according to Jane Wardle, a professor of clinical psychology at University College London. "I looked at the figures showing rates of obesity in the population over many years, and it seemed very clear [that] it began between 1984 and 1987," Wardle said in a debate at the Cheltenham Science Festival, which took place from June 6-10."We looked at what changes were going on in the food and activity world at that time, and one of the striking differences was ... in the speed with which we could prepare a meal."The microwave oven first became a common household appliance in the mid-1980s. Wardle claims that the introduction of the microwave led to cheaper, easy meals -- including microwave dinners -- appearing in stores."I'm not trying to demonize the microwave, but it was emblematic of a change that took place in the 1980s in terms of the availability of food -- a real change in the disincentives for eating."Between 1980 and 2004, obesity rates in the United Kingdom skyrocketed from 8 percent of women and 6 percent of men to 24 percent of both men and women. From 1995 to 2003, the rate of obesity among children leaped from 10 to 16 percent.Also at the Cheltenham Science Festival, two other researchers suggested alternate explanations.Ken Fox, a professor of exercise and health science at the University of Bristol, attributed rising obesity to the widespread introduction of new technology after World War II that largely replaced physical labor "in both work and leisure."Tim Lang, a professor of food policy at City University in London, instead blamed the introduction of supermarkets, "heralding the late 20th century food revolution in which prices have tumbled, car use skyrocketed [and] physical activity plummeted."