Acting this way, a freegan has no responsibility for the material and energy resources wasted in the production process, since the goods have already exited the production-consumption cycle where money is used in exchange for goods.
In most developed countries, the quality demands and hygiene standards of consumers are so high that many foods stay perfectly edible for long periods of time after their expiry or "best before" dates. Naturally, the best seasons for freeganism are autumn and spring, when waste bins remain at refrigerator temperatures.
Freeganism in itself does not mean a person is following a certain kind of dietary behaviour, though it is common that freegans often practice vegetarianism or veganism.
Most likely the majority of people practicing this diet are forced into it simply by lacking the income necessary to purchase food normally, rather than making a conscious decision to sustain themselves via dumpster diving when other choices are available. They are called bums.
wikipedia.org dumped 2003-03-17 with terodump