Figure 4.

Alternate day fasting (ADF) increases activity levels and reduces body temperature in rats. Young adult male Sprague Dawley rats were implanted with transmitters to enable continuous recording of activity and body temperature in the home cage. After recording activity and temperature on the usual ad libitum diet (baseline), the rats were maintained on an ADF diet for 2 months. Examples of 24 h recordings of activity (A) and body temperature (B) from one rat are shown at baseline, on a feeding day and on a fasting day; food was either removed or supplied at 16:00 h, which was 2 h before the start of the dark period. Overall activity is greater in both the dark and light periods when the rats are on the ADF diet compared with baseline, and that during the fasting day there is a robust increase in activity beginning ∼2 h before feeding time. Values are mean ± SEM (n = 6 rats).