Fig. 1.

Restoration of caloric balance occurs within 3 days of exposure to a high-fat diet (HFD). A: graphical illustration of the experimental timeline. B: graphical summary of caloric intake following exposure to an HFD. Single-housed rats were fed a control diet and, after acclimation, continued on a control diet (n = 4) or fed an HFD (n = 17). Rats were weighed daily, and their total food intake was calculated. Note that rats became hyperphagic and consumed a larger number of calories immediately upon exposure to the HFD (day 1). By day 3 onward, however, energy balance had been restored, and there were no differences in caloric intake between control and HFD-fed rats. *P < 0.05 (Student’s paired t-test). C: graphical summary of caloric intake following exposure to an HFD, expressed as a percentage of averaged baseline control intake. Note that caloric intake increased in 16/17 rats after 1 day of food intake but was restored to within 25% of baseline levels by 2 days in 7/16 rats, and by 3–5 days in the remaining 9/16 rats. Mean values for each day are marked by gray horizontal lines; the black dashed line indicates 125% of baseline caloric intake.