Twenty male Sprague-Dawley rats previously used for other purposes (Mackechnie et al., 2008 and Govind et al., 2008) were used in this pilot study. Rats were ~ XXX days old at the onset of this experiment and weighed 588 ± 51 grams. Rats were housed individually in plastic cages with bedding and provided ab libitum rat chow (Harlan Teklad 8604) and water. Rats were maintained on a 12:12 hour light dark schedule (lights on at 8 AM). Establishing the Baseline Rate of Eating After a 24 hour food deprivation once per week, rats were weighed and returned to their cages without bedding. At time zero (approximately 9 AM; one hour into the light period) a Froot Loop® was inserted into the cage through the lid and the observer began recording the time with a stopwatch. Once that Froot Loop had been consumed, another Froot Loop was immediately inserted into the cage and the time to consume the Froot Loop was recorded to the nearest second. This process was repeated until the rat failed to consume a Fruit Loop for 10 min at which time the meal was considered terminated. Meal duration, number of Froot Loops eaten, grams of Froot Loops consumed, and time to consume each Froot Loop was recorded for all 20 rats. Rate of intake was calculated as # FL consumed/meal duration. Five observers recorded data for each of four rats during each trial. Trials were repeated weekly until the baseline (unrestricted) rate of intake had stabilized. In an additional trail, 24-hr food deprived rats were provided ad libitum access to a pre-weighed bowl of FL inserted into the cage. FL intake and rate of intake was not affected by the mode of FL delivery (individually or via a bowl; data not shown.) Does slowing the rate of intake lead to reduced food consumption in laboratory rats? Travis Boyd, Brandon Hunt, and G.R. Davis Department of Biology, Wofford College, Spartanburg, SC Introduction Summary of Results Status of Hypothesis It has been speculated that reducing the rate of food intake will lead to a reduction in overall food consumption. If so, eating slowly may be an effective behavioral strategy for weight management. In 2007, Corby et al. reported that reducing the rate of food consumption resulted in reduced food intake in men but not in women. statement about regulating intake in rats feed a glucose solution at a constant rate but with experimental pauses….these rats regulated their intake regardless of the duration or number of introduced interruptions of a liquid meal of 12.5% glucose (Seeley et al., 1993). However, the mechanisms underlying the termination of a meal may differ for meals consisting of liquid or solids. Our purpose here is to determine whether reducing the rate of food consumption in hungry male Sprague- Dawley rats will result in reduced intake of a highly palatable solid food. Having established the baseline (unrestricted) rate of Froot Loop intake as 1 FL every 30 seconds, the hypothesis was tested by restricting the rate of intake to 1 FL every 60 seconds (R ½) or 1 FL every 120 seconds (R ¼ ). Following a standard 24 hour food deprivation, Froot Loops were inserted into the cage through the lid at 60 second intervals (2 rats per observer) or 120 second intervals (2 rats per observer). Observers recorded the time required to consume each FL to the nearest second. As before, the meal was considered terminated if the rat refrained from the Froot Loop for 10 min. Meal duration, grams of Foot Loops consumed, the number of Froot Loops consumed, and time to consume each Froot Loop was recorded for all 20 subjects. This experiment was counterbalanced by having each rat restricted at both rates separated by two weeks. Hypothesis Reducing the rate of food consumption will result in decreased food intake in laboratory rats. Determining Unrestricted Eating Speed Methods Acknowledgements Overview of Experiments Describe the 2 phases of the experiment Reducing the rate of eating did not affect total Fruit Loop intake. Restated, eating more slowly did not affect the amount of food eaten. Reducing the rate of Fruit Loop intake did not result in reduced Fruit Loop consumption. Average meal duration increased by factors of two and four when rate of consumption was restricted was restricted to one-half and one-fourth of baseline rate, respectively. Fruit Loop intake did not differ significantly between restricted and unrestricted trials nor did the mode of delivery of FL affect overall consumption.. Restricted Feeding Discussion These results show that reducing eating speed is not effective as a strategy to reduce food intake in non- naïve male laboratory rats. These results differ from that reported for human males by Corby et al., 2007 who showed that men consume less fried chicken when their rate of intake was experimentally reduced. Take together, these observations suggest that although the mechanism regulating food intake is similar in rats and humans, there may be important differences which limit the usefulness of Sprague-Dawley rats as animal models for human feeding behavior. Latency was not initially accounted for; however, meal duration with latency accounted for was not significantly different from meal duration without latency accounted for. Limitations of our experiment: a) Non-naive rats. b) Did not initially consider latency to eat FL c) Essentially we did not reduce the time to consume each Froot loop. Our protocol introduced pauses similar to that used by Seeley et al 1993 who tested with a glucose solution. Our results are similar to theirs and our conclusions are the same; rats compensate for interruptions of a meal by extending the meal such that total intake is kept relatively constant. Future experiments: a) non-food deprived rats. B) test a different type of solid food which different sensory properties and macronutrient content. C) potential differences in male and female rats re. Corby study found different results in men and women. The authors are indebted to Kelsi Koenig, Nicole Woller, and Kelly Berry who assisted with data collection and animal care. This project was funded by a Community of Scholars grant from the Fullerton Foundation to Wofford College. Text interpreting Figure 1 and 2 above. Mention statistics (ANOVA followed by post hoc pairwise testing (Student-Newman-Keuls, p <0.05) Number and mass of Fruit Loops consumed in Unrestricted Trials 1 and 2 differed significantly from Unrestricted Trial 4; these differences are likely due to neophobicity. There is also a significant difference in the rate of Fruit Loop intake in Unrestricted Trial 1 from that of Unrestricted Trial 4 again attributed difference to neophobicity. Text interpreting Figure 3 and 4 above. Mention statistics (ANOVA followed by post hoc pairwise testing (Student-Newman-Keuls, p <0.05)