Funded by the Canadian Institutes of Health Research, the study analyzed data from nearly 36,400 American adults from 1971 to 2008 as well as the physical activity frequency data of 14,419 adults from 1988 to 2006. “We observe that for a given amount of self-reported food intake, people will be about 10 per cent heavier in 2008 than in 1971, and about five per cent heavier for a given amount of physical activity level in 1988 than 2006,” said Ruth Brown, lead researcher and a graduate student at York University in Toronto.