"Richer, fatter, and not much happier," is how the Worldwatch Institute summed up the findings of its State of the World 2004 report, released on Thursday.
While rising consumption has created jobs, the US environmental group warned that "unprecedented" consumer appetite is damaging natural systems which we depend on.
One of the authors of the report said "consumption seems to have the character of a runaway trend."
"Consumption continues to grow in wealthy countries where basic needs have been met," Gary Gardner told a press conference.
"It is time to rethink the way we consume."
The group said in a statement - which was printed on recycled paper with vegetable oil-based inks - that the United States now has more privately owned automobiles than it does licensed drivers.
US refrigerators swelled by some 10% between 1972 and 2001, it said, while new homes were 38% bigger in 2000 than in 1975, even though the average household has fewer people in it.