Researchers at the University of Toronto found that it was easier to stay slim in the 1980s: looking at data about diet and exercise for tens of thousands of people since the early 1970s, they found that people today seem to be heavier than their forebears, even when they ate the same and were equally as active. One of the favored explanations for this is that young people today have denuded gut bacteria; a separate large study of European microbial genes has shown that a less diverse microbiome is correlated with a tendency to be obese.
