Calorie restriction still works in mice in cages with wheels (they often run 6 miles per night). I do not know if it has been tried with different numbers of mi

Calorie restriction still works in mice in cages with wheels (they often run 6 miles per night). I do not know if it has been tried with different numbers of mice per cage or in "enriched" environments. See for a very good review: http://jn.nutrition.org/content/137/4/1078.full http://jn.nutrition.org/content/137/4/1078.full But I do acknowledge your underlying point -- that it is exceedingly difficult to know how well results from mouse studies can be generalized to humans. It is a big problem.