The life-shortening effect of reduced physical activity is abolished by a fat rich diet

In female mice on a control diet (3.6% fat) reduced physical activity leads to a reduction of the average life span. So the average age at death of an inactive group is 500 +/- 166 compared to 565 +/- 175 days in an active co ntrol group. If the animals are kept on a fat rich diet (12.4% fat) this ef fect of physical activity restriction is no longer observable and the avera ge age at death is 570 +/- 142 days, within the range of the control animal s. The increased fat intake seems to reduce the stress or to increase the r esistance to stress in the activity restricted animals. So stress is a cruc ial determinant of life span. (C) 1998 Elsevier Science Ireland Ltd. All ri ghts reserved.