1. www.buffalo.edu Introduction Background: Caffeine is the most commonly used psychoactive substance around the world (1). Not only does it affect sleep (2) but also affects mood (3-4) and appetite sensations (5). Potential confounding factors that alter caffeine’s effects on appetite sensations and mood include caffeine dose (3), gender (6), BMI (7), and withdrawal reversal (4). Studies have shown moderate (~3 mg/kg) caffeine doses have equivocal effects (3, 5) while high doses (>3 mg/kg) have deleterious effects (3, 5) on appetite sensations and mood. For example, when given 200 mg and 400 mg of caffeine there was an increase in nervousness, restlessness, and anxiousness compared to the no caffeine condition (3). Objective : The objective of the current study was to evaluate the dose response effect of acute caffeine administration on appetite sensations and mood and to identify any influences of gender, BMI, and/or withdrawal reversal. Materials and Methods Results: Appetite Sensations References 1.Nehlig A Are we dependent upon coffee and caffeine? A review on human and animal data. Neurosci Biobehav Rev 1992; 23:563-76. 2.Rogers PJ Caffeine and alertness: In defense of withdrawal reversal. J Caf Res 2014; 4:1-66. 3.Loke WH Effects of caffeine on mood and memory. Physiology 1988 44(3):367-72. 4.Richardson NJ, Rogers PJ, Elliman NA, O’Dell RJ Mood and performance effects of caffeine in relation to acute deprivation. Pharm Biochem Behav 1995; 52(2):313- 320. 5.Gavrieli A, Karfopoulou E, Kardatou E, Spyreli E, Fragopoulou E, Mantzoros CS, Yannakoulia M Effect of different amounts of coffee on dietary intake and appetite of normal-weight and overweight/obese individuals. Obesity 2013; 21:1127-1132. 6.Temple JL, Ziegler A Gender differences in subjective and physiological responses to caffeine and the role of steroid hormones. J Caf Res 2011; 1(1):41-48. 7.Kamimori G, Somani S, Knowlton R, Perkins R The effects of obesity and exercise on pharmacokinetics of caffeine in lean and obese volunteers. Clin Pharm 1987; 31:595-600. Conclusions and Future Directions Subjects: 18-50 year old adults (N=30), BMI ≤ 35 Design: This study utilized a randomized, double blind, placebo controlled dose response design where each participant was tested with all caffeine doses (0, 1, and 3 mg/kg) on different days. Each subject completed 4 sessions in the laboratory. The first 3 sessions were ad libitum breakfast sessions and the final session was used to collect additional data, to screen subjects for potential eating disorders, and to compensate them for their time. Anthropometric measures were collected at the first breakfast session to verify weight to provide a relative caffeine dose. In addition, usual caffeine consumption and habits were collected at the first session. The breakfast sessions started with collecting a 2.5-mL saliva sample via the passive drool method to assure compliance with caffeine abstinence. Subjects were either given 0, 1, or 3 mg/kg of caffeine into a preferred 350-mL beverage. Subjects rated their appetite sensations (hungry/full/thirsty/ desire to eat) and mood and emotions just prior to beverage consumption and again 30 minutes later. During the 30 minute wait, subjects were asked to recall their dietary intake for the previous day. After the 30 minutes participants had up to 30 minutes to eat as much or as little as they wanted from a North American style buffet breakfast (results not included). Dose Response Effect of Caffeine on Appetite Sensations and Mood Faryal Sahibzada, Leah Panek-Shirley, Erin O’Brien, Edison Wei Soon, Harminder Chonk, and Jennifer L. Temple Department of Exercise and Nutrition Sciences---University at Buffalo, Buffalo, NY Results: Subjective Physiologic Responses Acknowledgements Results: Mood and Emotions Analytic Plan Figure 1 : Mean ± SEM Desire to Eat at baseline and again after exposure. Repeated measures ANCOVA analysis revealed an interaction between caffeine dose and pre/post on Desire to Eat (F(2, 38) = 4.0; p = 0.026) with Desire to Eat decreasing from pre to post after the moderate caffeine dose (3 mg/kg). Figure 2: Mean ± SEM Hunger at baseline and again after exposure. Repeated measures ANCOVA analysis revealed an interaction among caffeine dose, pre/post, and BMI group on Hunger (F(2, 38) = 4.1; p = 0.025) with low caffeine dose (1 mg/kg) decreasing hunger among normal weight and moderate caffeine dose (3 mg/kg) decreasing hunger among overweight/obese. Summary * Figure 3 : Mean ± SEM ratings of “Life is Good” at baseline and again after exposure. Repeated measures ANCOVA analysis revealed an interaction among caffeine dose, pre/post and BMI on ratings of “Life is Good” (F(2, 40) = 4.3; p = 0.02) with moderate caffeine dose (3 mg/kg) decreasing ratings among overweight/obese participants. Figure 4: Mean ± SEM ratings of “Sad” in each caffeine dose condition. ANCOVA analysis revealed a significant interaction among caffeine dose, sex, and BMI group for ratings of “Sad” (F(2, 40) = 3.8; p = 0.031) with overweight/obese males rating “sad” as higher in the 1 mg/kg dose condition and OW/OB females significantly reducing ratings of “Sad” after 1 mg/kg and 3 mg/kg of caffeine relative to the 0 mg/kg condition. There was no effect of caffeine dose on these ratings in lean participants. The effects of caffeine on appetite sensations are mediated by BMI. Caffeine dose affects mood and this effect is mediated by both BMI and gender. While these findings describe the effects of acute caffeine administration on appetite sensations, mood, and emotions, future studies should evaluate the underlying mechanisms For appetite sensations Desire to eat decreased with moderate (3 mg/kg) caffeine dose Hunger varied by caffeine dose and BMI with hunger decreasing among normal weight with low dose (1 mg/kg) and overweight/obese with moderate dose (3 mg/kg) For mood and emotions (Behavioral Checklist) “Life is Good” decreased among overweight/obese adults at the moderate (3 mg/kg) caffeine dose “Sad” decreased among overweight/obese females with both caffeine doses compared to placebo and was increased at low caffeine dose among overweight/obese males Among overweight /obese mood changes are associated with alterations in eating and other lifestyle behaviors For subjective physiologic responses (Behavioral Checklist) “Sleepy” decreased the among normal weight adults at both caffeine doses “Sweaty” decreased among females at the low caffeine dose (1 mg/kg) and among males at the moderate dose (3 mg/kg) The differential response by genders demonstrates known gender differences in cardiovascular response The Behavioral Checklist was a 1 to 7 Likert scale while the Appetite sensations was a 1 to 5 Likert scale. MalesFemales Lean (n=6) Overweight/ Obese (n=12) Lean (n=7) Overweight/ Obese (n=5) Mean ± SEM Age23 ± 3.827.3 ± 3.626.8 ± 2.831.3 ± 5.4 BMI22.9 ± 129.1 ± 0.9722.06 ± 0.727.9 ± 1.1 Usual Daily Caffeine (mg/d) 274.4 ± 91.3153.04 ± 84.5206.6 ± 64.6169.3 ± 100 Data were analyzed using a mixed analysis of co-variance with sex as the between subjects factor, caffeine dose as the within subjects factor, time (pre/post) as the repeated measure, and daily caffeine use as the covariate. Data were considered significant if p < 0.05. SYSTAT 11.0 was used for all analyses. Figure 5: Mean ± SEM ratings of “Sleepy “ at baseline and again after exposure. Repeated measures ANCOVA analysis revealed an interaction among caffeine dose, pre/post, and BMI group (F(2, 40) = 3.3; p = 0.048) with 1 mg/kg and 3 mg/kg of caffeine reducing ratings of “Sleepy” in normal weight participants, but having no impact in the OW/OB group. Figure 6: Mean ± SEM “Sweaty” at baseline and again after exposure. Repeated measures ANCOVA analysis revealed an interaction among caffeine dose, pre/post, and gender on ratings of “Sweaty” (F(2, 40) = 3.9; p = 0.028) with ratings of “Sweaty” significantly decreasing among males at the moderate caffeine dose (3 mg/kg) and females at the low caffeine dose (1 mg/kg). * 0 1 3 * * NW OW/OB * NW M NW F OW/OB M OW/OB F * * * * NW OW/OB The authors and researchers on this study would like to thank the participants as well as the Nutrition and Research Lab staff. MALE FEMALE * * *