Recent pre-clinical (1) and epidemiological (2) evidence suggests that temporal feeding patterns may influence metabolic outcome and contribute to obesity (3). We have demonstrated that grazing and meal feeding with standard rodent chow exert small differential effects on growth and adiposity in rats and mice (4), but the potential impact of these feeding patterns on food choice is unknown. Male Sprague-Dawley rats (4 weeks old; Charles River, UK) were singly housed in our automated feeding station and fed a standard low fat chow (Harlan Teklad RM3) either ad libitum (AL; n=6), or in a grazing (GR; consumption of 1/24th of the total food intake of the AL-fed rats every 30mins during the dark phase; n=6) or meal-fed (MF; 3x 1h period of AL feeding at 18:00h, 23:30h and 05:00h; n=6) pattern for 21 days, with water available AL and a 12h light:12h dark cycle (lights on 06:00h). On day 12 access to standard chow was replaced by 4h AL access to two food hoppers containing either low fat diet (LFD; Special Diet Services 10% AFE Fat) or High fat diet (HFD; Special Diet Services 45% AFE Fat) at 18:00h. Food hoppers were weighed after 4h and feeding patterns resumed. This was repeated on day 16, but with LFD and HFD hoppers weighed every 30mins. Feeding patterns were replaced at 10:00h on day 20 with 24h AL access to LFD and HFD hoppers. All data presented are mean ± SEM with statistical comparisons performed by 1-way ANOVA and Bonferroni post hoc test, or paired Student’s t-test. As shown previously (4), GR and MF rats showed 19 and 22% reductions in cumulative food intake (P <0.0001) over the 21 days, accompanied by 15 and 18% reductions in body weight gain (P<0.01), and a 3.6% reduction in terminal nose-anus length in grazing rats (P <0.05). Although this reduction in total food intake was maintained in the 24h food choice test (P <0.05), total food intake was unaffected by GR or MF during either of the 4h food choice periods. During the first food choice test AL rats consumed 9.8±0.8g (63±7% LFD vs 37±7% HFD; P=0.144), GR rats 9.4±1.0g (57±13% LFD vs 43±13% HFD; P=0.618) and MF rats 9.9±1.1g (78±6% LFD vs 22±6% HFD; P=0.0107). Food choice profiling (day 16) revealed that, following the initial meal consumed during the first 1h of the test by all three treatment groups (in which neither the total nor the proportion of HFD consumed were significantly different), AL, GR and MF rats consumed 6.2±0.8g (62±9% LFD vs 38±9 % HFD P=0.2491), 9.2±1.1g (58±13% LFD vs 42±13% HFD; P=0.5529) and 7.1±0.4g (88±2% LFD vs 12±2% HFD; P<0.0001) respectively. Thus, our data demonstrate that temporal feeding patterns influence food selection, meal feeding reducing preference for HFD. When seen in conjunction with evidence that meal feeding prevents HFD-induced obesity (1), our study indicates that grazing behaviour may represent a contributory factor in developing obesity.