*2.8. Episodic Intake of GM- and CM-Enriched Chow Presented Simultaneously in Sated Adult and Aged Rodents*

Mice and rats aged 18–20 weeks old mice (*n* = 8) and rats (*n* = 8) were included in the study on adults, whereas 25-month old mice (*n* = 9) and 27-month old rats (*n* = 10) were used as the aged cohorts. Adult rats and mice had been previously exposed to GM and CM chow (pre-exposure to both chow types was simultaneous). The aged animals came from the same cohort as in the GM/CM chow experiment described above (Section 2.5), however, a two-week-long 'washout' period was allowed between the previous experiment and this study. First, the animals were accustomed to receiving simultaneously CM- and GM-enriched chow in a subdivided hopper in their homecages (placement of GM/CM pellets was random; standard chow was removed) for circa 1 h per day on two days. Then, on the experimental day, after removal of standard chow, CM- and GM-enriched pellets (at room temperature) were given to the animals for 2 h (10:00–12:00). Intakes were measured using a digital scale after 2 h and expressed in grams per gram of body weight. This feeding experiment was conducted in a separate cohort of adult animals.
