7/27/2019 COMPONENTES DEL CHOCOLATE (COMBINACIONES DE GRASA Y AZUCAR QUE PRODUCEN PLACER O MS DESEO

1/5

Psychoactive effects of tasting chocolate and desire for more chocolate

Jennifer A. Nasser a,, Lauren E. Bradley a, Jessica B. Leitzsch a, Omar Chohan a, Kristy Fasulo a, Josie Haller a,Kristin Jaeger a, Benjamin Szulanczyk a, Angelo Del Parigi b

a Department of Nutrition Sciences, Drexel University, Philadelphia, PA 19102, United Statesb Department of Psychology, Drexel University, Philadelphia, PA 19102, United States

a b s t r a c ta r t i c l e i n f o

Article history:

Received 29 January 2011Received in revised form 23 April 2011Accepted 26 April 2011

Keywords:

Addiction Research Center InventoryARCIFood addictionCraving

The purpose of this study was to characterize the psychoactive effects of tasting chocolate and to evaluate the

contributionof themain chocolatecomponents to thedesireto consume more of it.A total of 280 participants,(F-155; M=125) ranging in age from 1865, completed the study. Participants were randomly assigned totaste 12.5 g of either white chocolate ( control) or one of four chocolate (cocoa) samples varying in sugar,fat andpercent cocoa content, then answered the question: Do you want more of this chocolate? and Ifyes,how many more pieces of this chocolate would you like to eat? They completed pre- and post-consumptionsurveys, consisting of 30 questions derived from the Addiction Research Center Inventory (ARCI) subscales,MorphineBenzedrine Group (MBG), Morphine (M) and Excitement (E). Significant decreases in postpreconsumption changes in MBG subscale were observed between the control sample and the 70% cocoa(p= 0.046) or the 85% cocoa sample (p= 0.0194). Proportionally more men than women wanted more of thetasted chocolate (p=0.035). Participants were more likely to want more of the tasted chocolate if theydisplayed a greater change in the MBG scale, and if their chocolate sample had high sugar and cocoa content,as assessed by multiple logistic regression. Our results suggest that multiple characteristics of chocolate,including sugar, cocoa and the druglike effects experienced, play a role in the desire to consume chocolate.

2011 Elsevier Inc. All rights reserved.

1. Introduction

Americans consume roughly 22 teaspoons (110 g) of added sugarper day [1]. Chocolate, a high sugar food, is considered to be the mostcraved substance in the U.S. [2,3]. Prior research suggests, however,that multiple components of chocolate, rather than just sugar, canpotentially contribute to the desire to consume chocolate [4,5].Theobromine and caffeine, (both methylxanthines contained incocoa) are usually cited as the most salient contributors to chocolatecraving [5]. However, Smit et al. [5] as well as Michener and Rozin [2]reported no role for the pharmacological content of methylxanthinesin the oro-sensory relief of cravings for chocolate, most likely due tothe lengthy post-ingestive time period (60120 min) required forcaffeine and theobromine blood levels to rise. Michener and Rozin [2]also reported that partial relief from craving for chocolate is observedeven with the consumption of white chocolate (which does notcontain cocoa, caffeine, and theobromine), and that an associationexists between chocolatecravingsand sensory properties of chocolatesuch as aroma, texture, and sweetness [2]. This suggests a prominentrole for the sugar (sweetness) as well as for the fat (texture and

aroma) components of chocolate in promoting desire for andconsumption of chocolate.

Animalstudies on theconsumptionof food sources of fatand sugarother than chocolate, either as single components or in combination,demonstrate activation of multiple neurotransmitter systems [68],specifically dopaminergic and opioidergic circuits.Sustained increasesin nucleus accumbens dopamine subsequent to consumption or shamfeeding of sugarsolutions[6] or corn oil solutions[7] can contributetofood wanting [9]. Neurobiological changes attributed to intake ofsugar and fat combinations include increased release of dopamine inthe cingulate cortex, hippocampus, nucleus accumbens, and locusceruleus, in addition to increased gene expression of the endogenousopioid dynorphin in the arcuate nucleus of the hypothalamus [10]which can contribute to food liking [11].

The simultaneous activation of dopaminergic and opioidergicsystems observed with ingestion and/or sham feeding of high fat andhigh sugar foods is similar to the pharmacodynamiceffects exerted bycombinations of a dopaminergic agonist (i.e. amphetamine, cocaine)and an opioidergic agonist, (i.e. morphine, heroin). These dopami-nergicopioidergic combinations are commonly referred to asspeedballs. Speedballs are more reinforcing than either dopami-nergic or opioidergic agonists used singularly, and produce a uniqueset of subjective effects [12] that can be measured using the AddictionResearch Center Inventory (ARCI) subscales [13,14]. As a mixture offat and sugar, chocolate might activate both the dopaminergic and

Physiology & Behavior 104 (2011) 117 121

Corresponding author at: Drexel University, 245 N 15th Street, Mailstop #1030,Philadelphia, PA 19102, United States. Tel.: +1 215 762 7363; fax: +1 215 762 4080.

E-mail address: jan57@drexel.edu (J.A. Nasser).

0031-9384/$ see front matter 2011 Elsevier Inc. All rights reserved.

doi:10.1016/j.physbeh.2011.04.040

Contents lists available at ScienceDirect

Physiology & Behavior

j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / p h b

http://dx.doi.org/10.1016/j.physbeh.2011.04.040http://dx.doi.org/10.1016/j.physbeh.2011.04.040http://dx.doi.org/10.1016/j.physbeh.2011.04.040mailto:jan57@drexel.eduhttp://dx.doi.org/10.1016/j.physbeh.2011.04.040http://www.sciencedirect.com/science/journal/00319384http://www.sciencedirect.com/science/journal/00319384http://dx.doi.org/10.1016/j.physbeh.2011.04.040mailto:jan57@drexel.eduhttp://dx.doi.org/10.1016/j.physbeh.2011.04.040

7/27/2019 COMPONENTES DEL CHOCOLATE (COMBINACIONES DE GRASA Y AZUCAR QUE PRODUCEN PLACER O MS DESEO

2/5

opioidergic systems simultaneously, although, Naleid et al. [8]reported that when rats were given access to a vanilla flavoredshake varying in fat and sugar, the sugar content was the mostreinforcing component.

In this human study, we characterized the psychoactive effects oftasting chocolate and investigated the contribution of the chocolatecomponents to the desire to consume more of the specific chocolatetested.

2. Methods and materials

2.1. Methods

2.1.1. Participants

This study was approved by theInstitutional ReviewBoard of DrexelUniversity and met the requirements for exempt review; consequently,no written consent was required before participants took part in theexperimental session. A sample of convenience, composed of 290passersbyat the Drexel UniversityStudent Center, volunteeredtofillouta survey before and after tasting a single 12.5 g sample of chocolatevarying in sugar, fat and percent cocoa content (Table 1). Whitechocolate was used as a control sample for chocolate, because it issimilar in mouth feel and sweetness but does not contain cocoa, and asorbitol-sweetened chocolatesample, similar inflavorandmouthfeeltothe other chocolate containing samples, was used to control for thecontributionof sugarto thepsychoactiveeffects of chocolate.We didnothave accessto a commercially available fat-free chocolate sample thathad similar flavor and mouth feel properties as the other chocolatesamples; therefore, no control forfat content effects wasincluded in ourstudy design. Volunteers were randomly assigned to taste 12.5 g ofeither white chocolate (i.e. control group) or one of four chocolatesamples (i.e. cocoa groups) varyingin sugar, fat andcocoa contents.Tenout of 290 participants failed to complete the study properly (either atethe chocolate before filling out the pre-consumption questionnaire ordid not complete the post-consumptionquestionnaire); therefore, theirdata were not used in the analysis.

2.1.2. Data analysisData were analyzed using SAS, ver. 8.2 (The SAS Institute, Cary,

NC). General linear models were implemented to compare generalcharacteristics (i.e. age, BMI, hunger, mood, chocolate liking andchocolate craving ratings) and ARCI subscale scores of each group(defined by the cocoa percentage of the chocolate sample tasted), andgender. ARCI subscale scores (pre- and post-chocolate consumption)were compared by paired t-Test. Segregation of desire to consumemore chocolate by gender was assessed by chi-square test. Multiplelogistic regression was employed to determine the individual vari-ables contributing to the desire to consume more of the chocolate thatwas tasted. The threshold of significance was set at alpha=0.05.

2.2. Materials

2.2.1. Background information questionnaire

Participants were given a background information questionnaireto complete. Height and weight were self-reported and BMI (kg/m2)

was calculated from the self-reported height and weight. Chocolatecraving and liking were assessed with a Likert Scale as follows: On ascale from 1 to 10 how much would you say that you cravechocolate? and On a scale from 1 to 10 how much would you saythat you like chocolate? Current hunger status was assessed using ananchored visual analog scale (VAS) with labeled intervals from 0 to100 displayed as follows: 0 = Not hungry at all; 20 = Slightlyhungry;40 = Moderately hungry; 60 = Quite hungry; 80 = Very hungry; and

100 = Extremely hungry. Current mood and alertness were assessedby anchored VAS with labeled intervals including 0 = Extremely sadand Extremely drowsy; 50 = Neutral; and 100 = Extremely happyand Extremely alert.

2.2.2. Addiction Research Center Inventory (ARCI)

A pre- and post-chocolate consumption questionnaire, composedof the exact same questions, was used to ask the volunteers a series ofquestionsdrawn from the following subscalesof the ARCI: MorphineBenzedrine Group (MBG), Morphine (M) and Excitement (E). Thesesubscales are a series of drug effect questions that describe subjectivefeelings of individuals after having taken particular drugs. Accordingto Haertzen and Hickey, [14] the MBG subscale measures well-being,euphoria, and optimal functioning, while the M subscale refers to

physical sensations of itching and tingling, and the E subscale relatesto physical signs of excitement, such as a fast heartbeat and light-headedness, as well as psychological feelings of well-being and thrill.

Selective use of various ARCI subscales has been reported in drugstudies [15,16]. Our questionnaire adapted the ARCI subscales (MBG,M, and E) by removing items that were redundant between scales(i.e., from the MBG subscale: I would be happy all the time if I felt as Ido now) or were not applicable to the study requirement ofcompleting the questionnaires immediately before and after tastinga small chocolate sample (i.e., from the MBG subscale: Today I saythings in the easiest possible way, and I feel high, or from the Msubscale: My speech is not as loud as usual). Described symptomsthat could be related to other conditions rather than to tasting thechocolate (i.e., from the M subscale: I have been scratching myself,

and

I have been dozing occasionally for seconds or minutes

) werealso removed. Additionally, the question My nose itches waschanged to My nose itches and/or is running as this is a possiblereaction to food. Pre- and post-consumption portions of the surveyasked a total of 30 ARCI questions. Answers to each ARCI questionwere true/false. Each subscale awarded one point to certain questionsif they were answered with the correct expected response (true orfalse); the total score was then tallied to give the subscale score perHaertzen and Hickey [14]. Two additional questions were included onthe post-consumption questionnaire: Would you want to eat more ofthis chocolate? and Ifyes, how many more pieces of this chocolatewould you like to eat? These two additional questionswere analyzedseparately and were not included as part of any subscale score.

3. Results

3.1. Demographics

Participant demographics are displayed in Table 2. There were nosignificant differences between groups (defined by cocoa content ofchocolate sample tasted)withrespect to number of subjects, gender, age,BMI, hunger, mood, chocolate liking, or chocolate craving. The averagevalue (MeanSD), for demographic variables across all participantswere: Age (yrs)2511,BMI (kg/m2)244,Hunger3326,Mood6318, Liking 8.52, Craving 6.12. Male (M) differed from female (F)participants in chocolate craving (M: 5.52.4; F: 6.62.4; t=3.74,p=0.0002) and liking (M: 8.21.7; F: 8.7 1.8; t =2.45, p=0.015), aswellasinBMI(M:24.53.9;F:22.93.7:t=3.48p=0.0006),butnotin

hunger (M: 3527; F: 3125; p= 0.15).

Table 1

Characteristics of chocolate samples.

Chocolate type % Cocoa Sugar (g) Fat (g)

Lindt white 0 7.0 4.5Lindt milk 38 7.0 3.9Russell Stover 60 7.0a 3.7Lindt dark 70 3.5 5.5Lindt dark 85 1.6 5.9

Content is per 12.5 g piece of chocolate.a

As sorbitol.

118 J.A. Nasser et al. / Physiology & Behavior 104 (2011) 117121

7/27/2019 COMPONENTES DEL CHOCOLATE (COMBINACIONES DE GRASA Y AZUCAR QUE PRODUCEN PLACER O MS DESEO

3/5

3.2. Effect of sugar, fat and cocoa on ARCI subscale scores

Cocoa groups differed from the control group in sugar, fat andcocoa contents of the sample. Significant within group increases wereseen between pre- and post-chocolate ingestions in the MBG subscalefor control and cocoa samples through 70% cocoa (Table 3). Betweengroup(cocoa groups versus control) differences in MBG score changeswere significant for the 70 and 85% cocoa groups (p=0.041 andp=0.019, respectively). These two groups had lower concentrationsof sugar: (3.5 g for the 70% and 1.625 g for the 85%) compared to thecontrol (7 g). In multiple regression models, including age, BMI,craving, liking, hunger, mood, grams of sugar, grams of fat, andpercent of cocoa, changes in MBG score were associated with liking(p=0.034), while changes in the E score were associated with age(p=0.004), liking (p=0.029), percent of cocoa (p=0.015), andgrams of sugar (0.042). Changes in the M score were not significantlyassociated with any variable, but the association with cravingapproached significance (p =0.057).

3.3. Desire for more chocolate

A significantly greater number of men reported a desire for moreof the chocolate tasted compared to women (chi-square p= 0.0349).Among those reporting a desire for additional chocolate, thedifference in amount of additional pieces of chocolate desired

between men and women approached significance (M: 4.03.5;F: 3.02.5; F =3.5, p=0.064). Logistic regression analysis revealedthat the desire to consume more of the chocolate sample (which hadbeen tasted) was associated with a greater amount of sugar and cocoain the sample, and with greater post=consumption increases in theMBG subscale (Table 4).

4. Discussion

4.1. Summary offindings

Our data indicate that tasting chocolate has measurable psycho-active effects in humans, which in turn are associated with the desireto consume more of it. This desire is proportional to the chocolate's

sugar and cocoa contents. This is thefirst demonstration in humans ofsuch effects using a validated drug effects questionnaire. Theassociation of changes in MBG subscale with desire to consume

more chocolate is consistent with responses of well-being, euphoriaand optimal functioning obtained on the MBG subscale afterdopaminergicopioidergic drug administration [14], as is the positivecorrelation of MBG subscale with liking for chocolate, since likingis thought to be an opioid mediated phenomenon [11].

While changes in the E and M subscales didn't contribute to thedesire to consume more chocolate, liking contributed to the inter-individual variability in changes in the E and M scores. In addition,amount of sugar and percent cocoa contributed to changes in the Esubscale scorein response to tasting chocolate. We caninterpret theseassociations as related to a dopamine-mediated response as the Esubscale measures subjective signs of excitement (i.e. fast heartbeatand light-headedness) and psychological feelings of well-being andthrill [14], all thought to be dopaminergic-mediated responses.

While our human data agree with the rat data of Naleid et al. [8] onthe primacy of sugar content of a high fat/high sugar food in drivingintake and motivation to acquire that food, we also demonstrate asignificant contribution of % cocoa to the desire to consume morechocolate. This finding of a contribution of % cocoa to the desire toconsume more chocolate is consistent with that of Willner et al. [17]who demonstrated (in humans) a differential effect of choosing milkchocolate versus carob (a sugar containing, non-cocoa chocolate-tastesubstitute) in an operant task performed after induction of a negativemood due to listening to sad sounding music. Willner et al. [17] notethat this laboratory method of inducing negative mood, correlates withreal-life chronic mild stress. Several recent studies have alsodemonstratedtheassociationofdepressedmoodwithchocolatecraving

[1820]. The mood ratings reported in this studyaveraged 6318 on ascale of 0 (extremely sad) to 100 (extremely happy) which wouldsuggest that our participants are generally in a happy mood; however,sadness and stress are not synonymous. Therefore, since we did notspecifically ask about level of stress, this explanation is still speculative.

On the other hand, the contribution of cocoa to the desire toconsume more chocolate can be discussed in relation to a report byNaleid et al. [8], who found no added contribution to reinforcementfrom the vanilla flavoring of their high fat/high sugar shake.Differences between humans and rats in eating/feeding behavior arenot surprising as they are based on multiple and robust biological andenvironmental grounds. However, the chemical nature of vanillaflavoring versus chocolate flavoring may also have contributed to thisfinding. Theflavoring component of vanilla is an oil [21], which would

most likely have been concentrated in the fat component of Naleid'shigh fat/high sugar milk shake, while chocolate flavoring is liquefied,water soluble chocolate bean (chocolate liquor) [22]. The watersoluble chocolate liquor would have been concentrated in the sugarcomponent of the chocolates used in our study.

Since sugar was the more salient reinforcer of the fatsugarmixture, association with the sugar content could have improvedcocoa discrimination and promoted increased desire. Additionally, allof our participants reported consuming chocolate regularly, while therats in Naleid et al.'s [8] study were nave to the corn oil/sugarmilkshake with vanilla flavoring. Consequently, it is plausible thatlearned association between chocolate and pleasure contributed toour results, or that habitual consumption of chocolate entrained apositive reward response in our participants similar to that reported

by ngeles-Castellanos et al. [23] in a rodent model.

Table 2

Demographics of participants grouped by% cocoa of sample tasted. MeanSD.

Variable 0% Cocoa 38% Cocoa 60% Cocoa 70% Cocoa 85% Cocoa

N 57 57 55 57 54Women 33 31 26 31 34Men 24 26 29 26 20Age 24.9 9.5 23.8 8.7 28.2 12.4 24.8 11.3 26.4 11.3BMI 23.3 4.3 24.4 3.2 23.8 3.5 23.2 3.6 23.6 4.8Hunger 31 28 31 27 33 25 39 27 29 22

Mood 65 20 64 17 59 18 62 16 66 18Liking 8.2 1.8 8.4 1.8 8.7 1.2 8.3 2.0 8.6 1.8Craving 5.9 2.7 6.0 2.2 6.4 2.5 5.9 2.3 6.3 2.5

Table 3

Comparison of MBG changes: cocoa versus white chocolate control. MeanSD.

Variable 0% CocoaControl

38% Cocoa 60% Cocoa 70% Cocoa 85% Cocoa

N 57 57 55 57 54Pretaste MBG 5.03.6a 4.63.5b 5.13.4c 5.23.6d 5.33.5Posttaste MBG 7.03.9a 6.43.9b 6.83.9c 6.13.7d 5.84.2Change in MBG 2.02.1ef 1.8 2.9 1.7 2.6 0.9 2.6e 0.53.1f

Items with similar letters/symbols are significantly different.Pre- and post- taste MBG scores are compared within column; change in MBG scores

are compared between columns.

Table 4

Logistic regression of contributors to desireto consume more of thetasted chocolate.a

Variable O.R. CI (95%) Wald Chi-sq P

Sugar grams 3.789 1.39410.298 6.818 0.009Change in MBG 1.413 1.2101.650 19.126 b0.0001Cocoa (percent) 1.037 1.0021.073 4.314 0.038Fat grams 7.681 0.87567.460 3.382 0.066BMI 0.973 0.8851.069 0.334 0.6

a Analysis utilized data from samples containing cocoa.

119J.A. Nasser et al. / Physiology & Behavior 104 (2011) 117121

7/27/2019 COMPONENTES DEL CHOCOLATE (COMBINACIONES DE GRASA Y AZUCAR QUE PRODUCEN PLACER O MS DESEO

4/5

It is possible that the physical form of our stimulus (solidchocolate) versus the liquid shake used by Naleid et al. [8] couldhave affected the sensitivity to experiencing psychoactive effects fromour solid chocolate samples. In fact, the physical form of a drug isknown to affect the reinforcing effects and addiction potential ofstimulant and opioid drugs [2426]. The physical form of foods isknown to affect hunger and satiety in humans [27], and a similarphenomenon might also mediate sensory experiences from foods

varying in physical form, especially when they can activate opioider-gic and dopaminergic brain circuits. Drewnowski et al. [28] found thatthe perception of sweetness, fat content and creaminess was differentwhen assessed in liquid compared to solid form, and that fatdiscrimination required higher fat concentrations in solid fat-contain-ing food, compared to liquid fat-containing foods.

Positive psychoactive responses elicited by sweet taste are alsodemonstrated by our finding that a sample (60% cocoa) containingsorbitol,rather than sugar,was able to produce changes in MBGscoresequivalent to those produced by white chocolate and 38% cocoasamples (both containing an equivalent amount of sugar), possiblybecause sorbitol binds to the same taste receptors as sugar [29]. Thesimilar responses from the sugar containing samples and the sorbitolcontaining sample suggest that it is potentially the binding to thesweet receptor, ratherthan thetaste of sugar per se,that plays a majorrole in triggering the psychoactive effects of tasting chocolate. Studiesusing different classes of sweeteners would be needed to resolve thisissue.

Ourmost surprising result wasthat proportionally, more menthanwomen reported a desire to consume more chocolate despite havingsignificantly lower chocolate craving and liking scores. However,when asked to estimate how much more chocolate they would liketo consume, the actual amount of additional chocolate desired bymen, compared to that desired by women (4 pieces versus 3 pieces)merely approached significance (p=0.064). A number of factorscould possibly have contributed to the more frequent desire toconsume more chocolate in men compared to women. On average,men had a higher BMI compared to the women, raising the possibilitythat women of our sample could have been more concerned with

their body weight than the male participants and therefore more alerttoward consumption of high energy=dense food [30], such aschocolate. Furthermore, women may not have admitted to desiringmore chocolate due to social desirability bias [31]. Needless to say,these are hypotheses, given that we did not measure desired bodyweight or social desirability among our participants.

4.2. Limitations

The current study has several limitations. As an observationalstudy, we used commerciallyavailablechocolatesamples in which fat,sugar and cocoa were varied simultaneously. While using commer-cially available chocolate gave a real world value to our observa-tions, it hindered a direct assessment of the contribution of fat, sugar

and cocoa individually to the MBG effects experienced and the desireto consume more of this chocolate. Additionally, since we did notmeasure changes in brain dopamine or opioids, the involvement ofthese neurotransmitters in experiencing MBG effects from tastingchocolate remains to be determined. Furthermore, because wecollected data from passersby, we could not pre-select participantsbased upon characteristics that might have impacted the results, suchas eating behavior phenotype, or family history of obesity.

4.3. Conclusions

We have demonstrated that tasting chocolate has measurablepsychoactive effects and that sugar and cocoa contents of chocolateare primarily related to the desire to consume more of it. To our

knowledge this is the first report of use of a validateddrug-effect

questionnaire to probe the psychoactive effects experienced fromtasting a high sugar/high fat food. The data support our hypothesisthat the psychoactive effects of chocolate are positively correlatedwith its sugar content. In addition, the data also support thehypothesis that cocoa content contributes to desirability of chocolate.Further studies assessing the time course of individual and interactiveeffects of fat, sugar and cocoa on psychoactive responses, activation ofdopaminergic and opioidergic neurotransmitter circuits, and their

contribution to overconsumption of high energy-dense food seemwarranted.

Role of funding sources

This study was funded through start-up funds provided by theOffice of theProvost of DrexelUniversity.The Officeof the Provost hadno role in the study design, collection, analysis or interpretation of thedata, writing the manuscript, or the decision to submit the paper forpublication.

Contributors

JAN designed the study. LEB, JBL, OC, KF, JH, KJ, and BS draftedquestionnaire items, collected the data and contributed to the writingof the manuscript. JAN and ADP conducted the statistical analysis,interpreted the data, and wrote the manuscript.

Conflict of interest

There are no conflicts of interest for any of the authors.

Acknowledgments

We thank Richard W Foltin, PhD for assistance in the use andinterpretation of the ARCI, and Suzette M. Evans, PhD and Sami AHasim, MD for their helpful suggestions in revising the manuscript.

References

[1] Van Horn L, Johnson RK, Flickinger BD, Vafiadis DK, Yin-Piazza S, Added SugarsConference Planning Group. Translation and implementation of added sugarsconsumption recommendations: a conference report from the American HeartAssociation Added Sugars Conference 2010. Circulation 2010;122:2470 90.

[2] Michener W, Rozin P. Pharmacological versus sensory factors in the satiation ofchocolate craving. Physiol Behav 1994;56:41922.

[3] Osman JL, Sobal J. Chocolate cravings in American and Spanish individuals:biological and cultural influences. Appetite 2006;47:290301.

[4] Bruinsma K, Taren DL.Chocolate: foodor drug? J Am Diet Assoc 1999;99:124956.[5] Smit HJ, Gaffan EA, Rogers PJ. Methylxanthines are the psycho-pharmacologically

active constituents of chocolate. Psychopharmacology (Berl) 2004;176:4129.[6] Avena NM, Rada P, Moise N, Hoebel BG. Sucrose sham feeding on a binge schedule

releases accumbens dopamine repeatedly and eliminates the acetylcholine satietyresponse. Neuroscience 2006;139:81320.

[7] Liang NC, Hajnal A, Norgren R. Sham feeding corn oil increases accumbensdopamine in the rat. Am J Physiol Regul Integr Comp Physiol 2006;291:R12369.

[8] Naleid AM, Grimm JW, Kessler DA, Sipols AJ, Aliakbari S, Bennett JL, et al.Deconstructing the vanilla milkshake: the dominant effect of sucrose on self-administration of nutrient flavor mixtures. Appetite 2008;50:12838.

[9] Berridge KC. Food reward: brain substrates of wanting and liking. NeurosciBiobehav Rev 1996;20:125.

[10] Levine AS, Kotz CM, Gosnell BA. Sugars and fats: the neurobiology of preference. JNutr 2003;133:831S4S.

[11] Davis CA, Levitan RD, Reid C, Carter JC, Kaplan AS, Patte KA, et al. Dopamine forwanting andopioids for liking: a comparison of obese adultswith andwithoutbinge eating. Obesity 2009;17:12205.

[12] FoltinRW, Fischman MW. The cardiovascular and subjectiveeffects of intravenouscocaine and morphine combinations in humans. J Pharmacol Exp Ther 1992;261:62332.

[13] Hill HE, Haertzen CA, Wolbach Jr AB, Miner EJ. The Addiction Research CenterInventory: standardization of scales which evaluate subjective effects ofmorphine, amphetamine, pentobarbital, alcohol, LSD-25, pyrahexyl and chlor-promazine. Psychopharmacologia 1963;4:16783.

[14] Haertzen CA, Hickey JE. Addiction Research Center Inventory (ARCI): measure-ment of euphoria and other drug effects. In: Bozarth MA, editor. Methods ofassessing the reinforcing properties of abused drugs. New York: Springer-Verlag;

1987. p. 489

524.

120 J.A. Nasser et al. / Physiology & Behavior 104 (2011) 117121

7/27/2019 COMPONENTES DEL CHOCOLATE (COMBINACIONES DE GRASA Y AZUCAR QUE PRODUCEN PLACER O MS DESEO

5/5

[15] Holdstock L, King AC, de Wit H. Subjective and objective responses to ethanol inmoderate/heavy and light social drinkers. Alcohol Clin Exp Res 2000;24:789 94.

[16] McDonald J, Schleifer L, Richards JB, de Wit H. Effects of THC on behavioralmeasures of impulsivity in humans. Neuropsychopharmacology 2003;28:135665.

[17] Willner P, Benton D, Brown E, Cheeta S, Davies G, Morgan J, et al. Depressionincreases craving for sweet rewards in animal and human models of depressionand craving. Psychopharmacology (Berl) 1998;136:27283.

[18] Macht M, Dettmer D. Everyday mood and emotions after eating a chocolate bar oran apple. Appetite 2006;46:3326.

[19] Macht M, Mueller J. Immediate effects of chocolate on experimentally induced

mood states. Appetite 2007;49:667

74.[20] ParkerG, CrawfordJ. Chocolatecravingwhen depressed: a personality marker. BrJPsychiatry 2007;191:3512.

[21] Sinha Arun K, Sharma Upendra K, Sharma Nandini. A comprehensive review onvanilla flavor: extraction, isolation and quantification of vanillin and othersconstituents. Int J Food Sci Nutr 2008;59:299 326.

[22] Luna F, Crouzillat D, Cirou L, Bucheli P. Chemical composition and flavor ofecuadorian cocoa liquor. J Agric Food Chem 2002;50:3527 32.

[23] Angeles-Castellanos M, Salgado-Delgado R, Rodriguez K, Buijs RM, Escobar C.Expectancy for food or expectancy for chocolate reveals timing systems formetabolism and reward. Neuroscience 2008;155:297307.

[24] Verebey K, Gold MS. From coca leaves to crack: the effects of dose and routes ofadministration in abuse liability. Psychiatr Ann 1988;18:51320.

[25] Foltin RW, Fischman MW. Self-administration of cocaine by humans: choicebetween smokedand intravenouscocaine. J Pharmacol Exp Ther 1992;261:8419.

[26] Swift RM, Lewis DC. Pharmacology of drug dependence and addiction. In: GolanDE, Tashjian Jr AH, Armstrong EJ, Armstrong AW, editors. Principles ofpharmacology: pathophysiologic basis of drug therapy. 2nd ed. Philadelphia:Lippincott, Williams and Wilkins; 2005. p. 292.

[27] Tieken SM, Leidy HJ, Stull AJ, Mattes RD, Schuster RA, Campbell WW. Effects ofsolid versus liquid meal-replacement products of similar energy content onhunger, satiety, and appetite-regulating hormones in older adults. Horm Metab

Res May 2007;39(5):389

94.[28] Drewnowski A, ShragerEE, LipskyC, StellarE, Greenwood MR.Sugarand fat: sensoryand hedonic evaluation of liquid and solid foods. Physiol Behav 1989;45:177 83.

[29] Jakinovich Jr W, Oakley B. Stimulation of the gerbil's gustatory receptors bypolyols. Brain Res 1976;110:50513.

[30] Neumark-Sztainer D, Sherwood NE, French SA, Jeffery RW. Weight controlbehaviors among adult men and women: cause for concern? Obes Res 1999;7:17988.

[31] Musher-Eizenman D, Carels RA. The impact of target weight and gender onperceptions of likeability, personality attributes, and functional impairment. ObesFacts 2009;2:3117.

121J.A. Nasser et al. / Physiology & Behavior 104 (2011) 117121