American Journal of Food Science and Health
Articles Information
American Journal of Food Science and Health, Vol.6, No.1, Mar. 2020, Pub. Date: Feb. 14, 2020
A Cross Sectional Study on Caffeine Consumption and Caffeine Expectancy Among Undergraduate Medical Students
Pages: 12-22 Views: 73 Downloads: 114
[01] Sowmiya Rajeswaran, Faculty of Medicine, Melaka Manipal Medical College, Manipal Academy of Higher Education (MAHE), Melaka, Malaysia.
[02] Muhammad Zulkhairie Bin Zulkifli, Faculty of Medicine, Melaka Manipal Medical College, Manipal Academy of Higher Education (MAHE), Melaka, Malaysia.
[03] Nurul Atasya Binti Budi Irawan, Faculty of Medicine, Melaka Manipal Medical College, Manipal Academy of Higher Education (MAHE), Melaka, Malaysia.
[04] Norarina Binti Mohd Seh, Faculty of Medicine, Melaka Manipal Medical College, Manipal Academy of Higher Education (MAHE), Melaka, Malaysia.
[05] Lee Ser Yin, Faculty of Medicine, Melaka Manipal Medical College, Manipal Academy of Higher Education (MAHE), Melaka, Malaysia.
Caffeine is the most commonly consumed psychoactive substance in the world and not only found in coffee, but also present in other products that includes tea, energy drinks, caffeine containing medicine and soft drink. The aim of conducting the research is to study caffeine expectancy with gender, ethnicity, type of caffeinated products and frequency based on dependence/ withdrawal, work enhancement, appetite suppression, mood enhancement, physical performance, negative physical effect and also on sleep disturbance. A cross sectional study was conducted from October to December 2019 in our college. Purposive sampling was used to enroll students for this study and they were asked to respond to the validated questionnaires on a Liker scale. A questionnaire related to the caffeine expectancy was used in this study. Each of the question represents a domain that we can elicit based on the expectancy towards caffeine consumption which are dependence/withdrawal, physical enhancement, mood enhancement, appetite suppression, negative effect, sleep disturbance and work enhancement. The analysis included frequency, percentages, mean, standard deviation, unpaired T-test and ANOVA. A total of 127 participated in this study; we find that 70.9% of medical student consumed caffeine in the form of tea, 68.5% in the form of coffee and 43.3% in form of soft drinks or energy drinks. Most of the medical student aware and expect the positive effect towards caffeine consumption but less awareness on its negative side effect such as appetite suppression and dependence/withdrawal. But for the sleep disturbance, most of them are fully aware about this effect and that’s is the most reason they consume caffeine in the night so that they can study effectively. Based on gender, there is no different on the expectancy towards caffeine consumption between female and male. But according to ethnicity, there is different on how they expect towards caffeine consumption; where Chinese has the least expectancy on work enhancement after consume caffeine while Malay and Indian has the least expectancy on negative effect after caffeine consumption. Most of the medical students that consume the caffeinated products believed that by consuming caffeine will increase the productivity. Students believes that caffeine can make them more alert, more energetic, and even improves their concentration, attention and motivation towards work. Future research should explore the association between caffeine dose with the caffeine expectancy. Study on psychometric assessment such as stress and anxiety can be conducted along with caffeine expectancy.
Caffeine, Cross-sectional, Medical Students
[01] Temple, J., Bernard, C., Lipshultz, S., Czachor, J., Westphal, J. and Mestre, M, the Safety of Ingested Caffeine: A Comprehensive Review, Frontiers in Psychiatry. 2017; 8: 80.
[02] Huntley, E. and Juliano, L., Caffeine Expectancy Questionnaire (CaffEQ): Construction, psychometric properties, and associations with caffeine use, caffeine dependence, and other related variables, Psychological Assessment. 2012; 24 (3): 592-607.
[03] [Internet]. How Should We Approach Habitual Caffeine Use by Athletes? c2019 [cited 2019 Nov 11]. Available from:
[04] [Internet]. Global coffee consumption, 2017/18 | Statista; c2019 [cited 2019 Nov 11]. Available from:
[05] Khan MS, Nisar N, Naqvi SAA, Nawab F. Caffeine Consumption and Academic Performance among Medical Students of Dow University of Health Sciences (DUHS), Karachi, Pakistan, An-nals ASH KM&DC. 2017; 22: 81-7.
[06] Adam M Gonzalez, Allyson L. Walsh, Nicholas A. Ratamess, Jie Kang, Jay R. Hoffman, Effect of pre-workout energy supplement on acute multi-joint resistance exercise, Journal of sport science and medicine. 2011 Jun; 10 (2): 261–266.
[07] Tom M. McLellan, John A. Caldwell, Harris R. Lieberman, A review of Caffeine's Effects on Cognitive, Physical and Occupational Performance, Neuroscience & Biobehavioral Reviews. 2016 Dec; 71: 294-312.
[08] Kyujin Han, Jiyeon Lee, Bo Yoon Choi, Hamin Jeong, Jae Hoon Cho, Jin Kook Kim, Does Improved Attention Induced by Caffeine Intake Affect Olfactory Function?, Clinical and Experimental Otorhinolarngology. 2019 March 1.
[09] Jay R. Hoffman, Caffeine and Energy Drink, Strength And Conditioning Journal. 2010 Feb; 32 (1): 15-20.
[10] [Internet]. Hannah Nichols, What does caffeine do to your body? c2019 [cited 2019 Nov 11]. Available from:
[11] Astrid Nehlig, Is Caffeine a Cognitive Enhancer?, Journal of Alzheimer’s disease. 2010 April 14; 20 (1): S85-S94.
[12] Rogers, P., Heatherley, S., Mullings, E. and Smith, J. Faster but not smarter: effects of caffeine and caffeine withdrawal on alertness and performance, Psychopharmacology. 2012 October 30; 226 (2): 229-240.
[13] Hughes, John R. Oliveto, Alison H. Helzer, John E. Higgins, Stephen T. Bickel, Warren K, Should caffeine abuse, dependence, or withdrawal be added to DSM-IV and ICD-10?, American Journal of Psychiatry. 2006 April; 149 (1): 33-40.
[14] Juliano LM, Griffiths RR, A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features, Psychopharmacology (Berl). 2004 Oct; 176 (1): 1-29.
[15] [Internet]. Clare Wood, Topend Sports, science, training and nutrition, Caffeine - good or bad? c2019 [cited 2019 Nov 11]. Available from:
[16] Ruxton, C. H. S. The impact of caffeine on mood, cognitive function, performance and hydration: a review of benefits and risks, Nutrition Bulletin. 2008 Feb 13; 33 (1): 15–25.
[17] Mwape, R. and Mulenga, D, Consumption of Energy Drinks and Their Effects on Sleep Quality among Students at the Copperbelt University School of Medicine in Zambia, Sleep Disorders. 2019: 1-7.
[18] [Internet]. Janae Brown, Is caffeine bad for you? How to safely get your fix; c2019 [cited 2019 Nov 11]. Available from:
[19] Jin, M.-J., Yoon, C.-H., Ko, H.-J., Kim, H.-M., Kim, A.-S., Moon, H.-N., & Jung, S.-P. The Relationship of Caffeine Intake with Depression, Anxiety, Stress, and Sleep in Korean Adolescents, Korean Journal of Family Medicine. 2016; 37 (2): 111.
[20] Julia Frozi, Hudson W de Carvalho, Gustavo L Ottoni, Rodrigo A Cunha, Diogo R Lara. Distinct Sensitivity to Caffeine-induced Insomnia Related to Age. Journal of Psychopharmacology. 2018; 32 (1): 89-95.
[21] Yousif Al-turki, Basel Alenazy, Abdulrhman Algadheeb, Mazi Alanazi, Abdulsalam Almarzouqi, Abdulrahman Alanazi, Abdulelah Alanazi, Mohammed Alanazi, Caffeine Habits among Medical Students in King Saud University. International Journal of Science and Research (IJSR). 2016 Feb; 5 (2): 754-764.
[22] Lee, K., Human, G., Fourie, J., Louw, W., Larson, C. and Joubert, G. Medical students' use of caffeine for ‘academic purposes’ and their knowledge of its benefits, side-effects and withdrawal symptoms, South African Family Practice. 2009; 51 (4): 322-327.
[23] Raj, V. P. R. B. Ranjith; Devi, R. Gayatri; Priya, A. Jothi, Awareness on the effects of caffeine among students-A survey, Drug Invention Today. 2018; 10: 2692-2695.
[24] Benjamin Perrodin, Psychological and situational predictors of caffeine consumption in daily life, 2017 December. Available from:
[25] Ágoston, C., Urbán, R., Király, O., Griffiths, M. D., Rogers, P. J., & Demetrovics, Z. Why Do You Drink Caffeine? The Development of the Motives for Caffeine Consumption Questionnaire (MCCQ) and Its Relationship with Gender, Age and the Types of Caffeinated Beverages, International Journal of Mental Health and Addiction. 2017; 16 (4): 981–999.
[26] Lieberman, H., Agarwal, S. and Fulgoni, V. Daily Patterns of Caffeine Intake and the Association of Intake with Multiple Sociodemographic and Lifestyle Factors in US Adults Based on the NHANES 2007–2012 Surveys, Journal of the Academy of Nutrition and Dietetics. 2009; 119 (1): 106-114.
[27] Markus Schott, Wolfgang Beiglbock, Rita Neuendorff, Translation and Validation of the Caffeine Expectancy Questionnaire (CaffEQ), International Journal of Mental Health and Addiction. 2016 August; 14 (4): 514-525.
[28] Joseph J. Knapik, Krista G. Austin, Susan M. McGraw, Guy D. Leahy, Harris R. Lieberman, Caffeine consumption among active duty United States Air Force personnel, Food and Chemical Toxicology Journal. 2017 July; 105: 337-386.
[29] Carolyn F. Brice, Andrew P. Smith, Factors associated with caffeine consumption, International Journal of Food Sciences and Nutrition. 2002; 53: 55-64.
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