AbstractBackground: It is well documented that stress and anxiety can lead to over eating and obesity. The objective of the study was to explore the possible effect of academic examination stress on development of overweight/obesity in medical students.Materials and Methods: A cross-sectional study was conducted which included 150 first year medical students of 2013 batch . Perceived Stress scale questionnaire was given and assessed prior to and during the examination. BMI was calculated prior and after examinations for students with height and weight data.Results: Moderate amount of perceived Stress was prevalent among the students, more in the overweight BMI category of students and both Perceived Stress scores and BMI among medical students increased after exam and was found to be statistically significant.Conclusion: The positive correlation between PSS and B.M.I demonstrated that stress increases the development of overweight/Obesity.
Key words: Perceived Stress Scale(PSS). Obesity. Body Mass Index(BMI)
Stress is defined as body’s nonspecific response to any demand placed upon it whether it is caused by, or results in pleasant or unpleasant conditions.1Medical education is one of the stressful and an emotionally demanding training in which academic stress is one of the major stressor.2
A decline in physical & mental health among medical students has been associated with academic stress-perceived events such as exams, elevated workload or cognitive tasks. 3
There is strong evidence from both human and animal studies that stress can alter eating behaviour and food intake. 4-7
Previous research exploring association between academic examination stress and eating habits in students appears to be inconsistent. Some studies suggest that some are nonresponders to stress 8,some decrease their food intake and some increase their foodintake9-12which can lead to obesity.
The high prevalence of obesity is a major public health problem because of the association of obesity with chronic health conditions such as,Hypertension, Hyperlipidemia,Coronary heart disease, Type 2 diabetes & cerebrovascular accidents. 13
Hence the purpose of the current study was to investigate the possible effect of academic examination stress on development of overweight/obesity in medical students.
Materials and methods:
Study design: This is cross – sectional study at Bangalore Medical College &Research Institute, Karnataka, India, in a period of 2013-2014.
Study subjects: Out of 250 students of the year 2013 batch, 150 were selected as per inclusion and exclusion criteria.100 was males and 50 were females.
Data collection:one hundred and fifty medical students participated in this study All were told of the objective of the study and then called to participate in it. The data regarding stress levels and obesity were collected both in the pre-examination (one month before the examination) and later in the post-examination period (same day after the examination). Students with H/O psychiatric illness, medical illness on medication, was excluded from the study .Informed consent were taken. Strict confidentiality was assured to all participants.
Parameters which were studied
Perceived stress scale questionnaire: -10 item perceived stress scale, previously validated and utilized by several successful investigators researching student’s stress levels, was employed. The Perceived Stress Scale is a 10-item self-report questionnaire that measures the persons’ evaluation of the stressfulness of the situations in the past one month of their lives. The Perceived Stress Scale is the only empirically established index of general stress appraisal.
In the present study, the students were explained about the PSS scale questionnaire in detail and were told to tick the appropriate numbers.
Later, the total score was assessed. For each question, they had to choose from the following alternatives:
0 – never , 1 – almost never , 2 – sometimes , 3 – fairly often and 4 – very often
Assessing the PSS score:
The PSS score was determined by the following method: First, by reversing the scores for questions 4, 5, 7 and 8. On these 4 questions, the scores could change from: 0 = 4, 1 = 3, 2 = 2, 3 = 1, 4 = 0. Then, the scores were added up for each item to get the total.
The total score was represented as the stress score:
The individual scores on the PSS could range from 0 to 40, which were grouped into 3 groups. Scores ranging from 0-13 groped under low stress. Scores ranging from 14-26 grouped under moderate stress. Scores ranging from 27-40 grouped under high perceived stress.
The conventional anthropometric methods were included for the measurement of obesity/overweight, like- weight comparison (with the weight taken prior and after the time of medical examination), B.M.I. (Quetelet Index, WHO criteria). After B.M.I calculation the medical students were classified under various group of (1) underweight(< 18.5), (2) normal weight(18.50-24.99), (3) overweight(25.0-29.9), and (4) obese(30.0-34.9).
Conditions as per the WHO recommendations for adult Europids, 1998.
Statistics: The statistical analysis was done by using the Student’s unpaired ‘t’ test.
Statistical software: The Statistical software namely SAS 9.2, SPSS 15.0, Stata 10.1, MedCalc 9.0.1 ,Systat 12.0 and R environment ver.2.11.1 were used for the analysis of the data and Microsoft word and Excel have been used to generate graphs, tables etc.
Table 1 Comparison of PSS according to BMI category
|BMI(kg/m2)||Before examination||After examination||P value|
|PSS 1||PSS 2|
+ Suggestive significance (P value: 0.05<P<0.10),
* Moderately significant ( P value:0.01<P £ 0.05)
** Strongly significant (P value : P£0.01)
From table 1 shows that the PSS scores increased from 21.97±3.36 to 23.77±4.67 after examination in underweight BMI group which was statistically strongly significant (P value: <0.001**).
In normal weight BMI group also PSS Scores increased from 20.98±4.31 to 21.54±6.01 after examination which was statistically suggestive of significance (P value: 0.082+).
In overweight BMI group also PSS Scores increased from 22.57±3.32 to 22.86±6.54 after examination which was not statistically significant (P value: 0.791).
In obese BMI group PSS scores increased from 21.78±5.87 to 23.67±6.5 after examination which was statistically suggestive of moderate significance (P value: 0.027*).
Table 2 BMI and PSS before exams
|BMI 1(Before exam)
|PSS 1 SCORE(Before exam)( Mean±SD)|
Table 3: BMI and PSS immediately after exams
|BMI 2(After Exam)||PSS 2 SCORE(After exam)(Mean±SD)|
|NORMAL(n=115)||12.2±.79(10)||20.86 ±3.5(81)||29.96 ±3.26(24)|
Table 2 and table 3 shows that there is decrease in number of students in under weight BMI category ( 29 to 22) and increase in number of students in normal (112 to 115) and overweight(8 to 12) BMI categories. This suggests that weight gain has occurred in students though not to significant extent.
From table 2 and table 3 we can also observe that among different PSS groups number of students have increased in mild stress PSS group (2 to 12) and high stress PSS group (14 to 30) PSS groups after examination where as decreased in moderate stress PSS group(134 to 100). This suggests that is increase in number of students with stress in each group.
From table 2 and table 3 also shows that PSS scores have also increased in each groups in mild (12 to 13), moderate (22 ±2.65 to 22.72±3.2), high(28 to 30.75± 5.5) in underweight category students.
Mild( 20.86 ±3.5 to 20.86 ±3.5) moderate (20.42 ±3.26 to 20.86 ±3.5 ), high ( 29.27±2.37 to 29.96 ±3.26) in normal weight category students.
Mild(0- 8), moderate(19.33±2.73 to 20.25 ±3.3), high(31±4.243 to 34.5±3.5) in overweights category students. This also suggests that severity of stress has also increased in all BMI categories of students
Medical college is a challenging environment that requires students to deal effectively with stress borne out of the medical education environment, as well as their personal lives
Stress is defined as nonspecific response of the body under pressure 14 which can lead to favourable results is classified as eustress and unfavourable results like depression or anxiety termed as distress. 15
Previous research had revealed that the academic examinations increased stress level in medical students and may have very different psychological and immunological consequences .16 Our study observed that the perceived stress levels were high and significantly increased after exam. Also B.M.I levels increased significantly after the examination.
Our results suggest that BMI & stress levels were increased in response to the academic stress (examination) which can lead to overeating/weight gain/obesity. Our results are well in agreement with the previous studies where students experience stress during academic examination resulting in increased food intake and B.M.I. (8, 17, 18)
There is strong evidence from both human and animal studies that stress can alter eating behaviour food intake.
In our study we observed that stress is more in underweight(23.77±4.67) and obese (23.67±6.5) BMI category students(table 1). Examination Stress causes variations in eating behaviour. Some decrease their food intake, some increase their foodintake 9-12which can lead to obesity as shown by various studies. It is also suggested that some are nonresponders to stress 19,20.
In some Previous studies it was observed that stress-perceived events such as exam-stress,
elevated workloads and cognitive tasks are what result in increases in energy intake.(8,21,22,23). According to the results of a recent study, female medical students exhibited behavioural shifts like an increased consumption of food when stressed, coupled with an increased frequency of emotional eating and sedentary lifestyle leading to overweight/obesity 18. It is observed that people cope up with negative emotions generated by stressful events by engaging in emotional eating. 24
Adolescents report that stress is associated with a shift towards unhealthy eating practices 25
Perceived stress and binge eating frequency three times greater than reported by individuals with low negative stress26Stress induced eating studies have found that a preference for high energy dense food in response to stress, specifically women preferred sweets. 27
Prolonged sleep deprivation increases both food intake and energy consumption, as also a hormone imbalance is observed, leading to weight gain. 28
The immediate response to different stressors is the brain’s evaluation of the threat carried out by the amygdala, hippocampus and pre- frontal cortex .This activates the sympathetic-adrenal- medullary (SAM) axis which releases catecholamines such as epinephrine.
A more long-term response to stress is mediated by the hypothalamic- pituitary-adrenal (HPA) axis which releases glucocorticoids mainly cortisol29.
Animal and human studies have demonstrated that cortisol injections are associated with increased appetite, cravings for sugar, and weight gain 12.
Epel et al. demonstrated that premenopausal women who secreted more cortisol during and after novel laboratory stressors chose to consume more foods high in sugar and fat which leads to obesity. 30
High levels of cortisol cause fat stores and excess circulating fat to be relocated and deposited deep in the abdomen, which can develop into or enhance obesity. In addition, hypertension (high blood pressure), hyperlipidemia (elevated lipids), and hyperglycemia (elevated glucose) have been linked to elevated cortisol levels 31,32. Individuals with visceral obesity are at a greater risk for developing cardiovascular disease, type II diabetes mellitus, and cerebrovascular disease.
Stress and anxiety lead to release of naturally occurring opiate B- endorphin,which increases food intake, but also reduces the perception of pain and anxiety associated with stress. Their is increasing evidence to support that some people are prone to eating sweet,fatty,high energy foods during stress which may result in obesity. 33,34,35
In contrary to our results some previous studies observed that professional course environments precipitate high levels of stress, anxiety and depression that may contribute to poor eating habits 36,37,38. Anxiety and depression have been linked to changes in appetite, with a decline in healthy food choices and eating habits.39
It has also been observed in some previous studies that academic examinations are stressful but no significant change was observed in weight of medical students. 19,20
Overweight children scored significantly lower on the psychosocial health score compared to children of normal weight in a Cleveland, Ohio community-based sample.40
A positive correlation between perceived stress scale scores and Body Mass Index showed
Showed that there is a significant effect of academic examination stress on
Programs like regular stress assessment and counselling, conducting monthly tests, mock examinations can reduce the impact of academic examination stressor on physical and mental health of medical students.
An effective inclusion and implementation of regular exercise, sports and cultural activities and stress management program like meditation, yoga in the medical curriculum may be a key to reducing and or preventing stress-induced psychological distress and overweight/obesity. We also suggest that the examinations which causes mild to moderate stress that will condition the students and the efficacy of the General Adaptation Syndrome will be improved in such subjects.
Acknowledgement: All the first year medical students of 2013 batch who participated in this study.
Source of funding: Self
Conflict of interest: NIL
References upto introduction
1. Selye H, A syndrome produced by diverse nocuous agents, Nature, 138;32:1936.
2. Niaura R, Herbert PN, Saritelli AL. Lipid and lipoprotein responses to episodic occupational and academic stress. Arch Intern Med.1991; 151:2172-2179.
3. Bayram, N., & Bilgel, N. (2008). The prevalence and socio-demographic correlations of depression, anxiety and stress among a group of university students. Social Psychiatry and Psychiatric Epidemiology, 43(8), 667-72
4.Levine AS, Morley JE. Stress-induced eating in rats.Am J Physiol. 1981 Jul;241(1):R72-6.
5.Greeno CG1, Wing RR. Stress-induced eating. Psychol Bull. 1994 May;115(3):444-64.
6.Boggiano MM1, Chandler PC. Binge eating in rats produced by combining dieting with stress. Curr Protoc Neurosci. 2006 Aug;Chapter 9:Unit9.23A. doi: 10.1002/0471142301.ns0923as36.
7.King KA1, Vidourek R, Schwiebert M. Disordered eating and job stress among nurses.
J Nurs Manag. 2009 Nov;17(7):861-9. doi: 10.1111/j.1365-2834.2009.00969.x.).
8.Pollard TM1, Steptoe A, Canaan L, Davies GJ , Wardle. Effects of academic examination stress on eating behaviour and blood lipid levels.
Int J Behav Med. 1995;2(4):299-320.
9. Wallis DJ1, Hetherington MM. Stress and eating: the effects of ego-threat and cognitive demand on food intake in restrained and emotional eaters.Appetite. 2004 Aug;43(1):39-46
10. Koda S,Sugawara K.The influence of diet behavior and stress on binge-eating among female college students. The Japanese journal of psychology 07/2009; 80(2):83-9. DOI: 10.4992/jjpsy.80.83
11. Waaddegaard M1, Davidsen M, Kjøller M. Comparison between risk behaviour for eating disorders and SF-36 and perceived stress among 16-29-year old Danish women. Ugeskr Laeger. 2009 Feb 23;171(9):709-12.
12. Wallis DJ1, Hetherington MM. Emotions and eating. Self-reported and experimentally induced changes in food intake under stress. Appetite. 2009 Apr;52(2):355-62. doi: 10.1016/j.appet.2008.11.007. Epub 2008 Nov 24.)
13.NIH, NHLBI Obesity Education Initiative. Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults..AccessedDecember 14, 2011
14.Jones TL. Definition of stress eating disorders in women and children prevention stress management and treatment. Bocaraton CRS press. 2001;89-100.
15. Lazarus RS .From psychological stress to the emotions: a history of changing outlooks. Annual review of psychology 1993; 44: 1-22.
16. Stowell, J. R. (2003) : Use and abuse of academic ex-aminations in stress research. Psychosom Med 2003;65:1055–57.
18.Khushboo V, Shuchi G. Stress leading to overweight/obesity in First M.B.B.S. hosteller girls. International Journal of Collaborative Research on Internal Medicine and Public Health 2012: 4(6 ):924-933.
19.Balkishan Sharma e, Rajshekhar Wavare, Ajit Deshpande, Richa Nigam et al.A study of academic stress and its effect on vital parameters in final year medical students at SAIMS Medical College, Indore, Madhya Pradesh.Biomedical Research 2011; 22 (3): 361-365
20.Bellisle, F., Louis-Sylvestre, J., Linet, N., Rocaboy, B., Dalle, B., Cheneau, F.,Guyot, L. (1990).Anxiety and food intake in men. Psychosomatic Medicine, 52(4), 452-457.
21.Chaput, J. P., & Tremblay, A. (2007). Acute effects of knowledge-based work on feeding behaviour and energy intake. Physiology & Behavior, 90, 66–72. doi:10.1016/j.physbeh.2006.08.030
22.McCann, B. S., Warnick, G. R., & Knopp, R. H. (1990). Changes in plasma lipids and dietary intake accompanying shifts in perceived workload and stress. Psychosomatic Medicine, 52, 97-108
23.Michaud, C. l., Kahn, J. P., Musse, N., Burlet, C., Nicolas J. P., & Mejean, L. (1990). Relationships between a critical life event and eating behaviour in high-school students. Stress Medicine, 6, 57–64. doi: 10.1002/smi.2460060112.
24. Match M., Simons G. Emotions and eating in everyday life. Appetite.2000; 35(1):65-71.
25. Cartwright M, Wardle J, Steggles N, Simon CE, Croker H. Stress and dietary practices in adolescents. Health Psycol. 2003; 22(4):362-369.
26. Pendleton W., Poston S., Goodrick R., Foreyt .Negative stress and outcome for treatment for binge eating. Eating Disord.2001; 9(4):351-360.
27. Grunberg NE, Straub RO. The role of gender and taste class in the effects of stress on eating. Health Psycol.1992; 11:97-100.
28. Taheri S, Lin L, Austin D, Young T, Mignot E. Short sleep duration is associated with reduced leptin, elevated ghrelin and increased body mass index. 2004; PLoS Med
1(3):e62.doi.10.1371/journal.pmed.0010062.Assesed on 1 September 2009
29. McEwen, B. S., & Gianaros, P. J. (2011). Stress- and Allostasis-Induced Brain Plasticity. Annual Review of Medicine, Vol 62, 2011, 62, 431-445.
30. Epel, E., R. Lapidus, B. McEwen, et al. Stress may add bite to appetite in women: a laboratory study of stress-induced cortisol and eating behavior.Psychoneuroendocrinology 26: 37-49, 2001.
31. Andrews, R.C., O. Herlihy, D.E.W. Livingstone, et al. Abnormal cortisol metabolism and tissue sensitivity to cortisol in patients with glucose intolerance.The Journal of Clinical Endocrinology 87(12): 5587-5593, 2002.
32. Mariemi, J. E., Kronholm, S. Aunola, et al. Visceral fat and psychosocial stress in identical twins discordant for obesity. Journal of Internal Medicine 251: 35-43, 2002.
36.Dyson, R., & Renk, K. (2006). Freshmen adaptation to university life: Depressive symptoms, stress, and coping. Journal of Clinical Psycholgoy, 62(10), 1231-1244. doi: 10.1002/jclp.20295
37.Misra, R., & Castillo, L. G. (2004). Academic stress among college students: Comparisons of American and international students.
International Journal of Stress Management, 11(2), 132-148. doi: 10.1037/1072-5245.11.2.132
38.Oliver, G., Wardle, J., & Gibson, E. L. (2000). Stress and Food Choice: A Laboratory Study.Psychosomatic Medicine, 62(6), 853-865
39.Fulkerson, J. A., Sherwood, N. E., Perry, C. L., Neumark-Sztainer, D., & Story, M. (2004). Depressive symptoms and adolescent eating and health behaviors: A multifaceted view in a population- based sample. Preventive Medicine, 38, 865-875. doi: 10.1016/j.ypmed.2003.12.028.
40. Friedlander SL, Larkin EK, Rosen CL, Palermo TM, Redline S: Decreased quality of life associated with obesity in school-aged children.Arch Pediatr Adolesc Med 2003, 157:1206-1211.
First Author –Dr. Shashikala K.T,
Assistant professor of Physiology,
Bangalore Medical College & Research Institute
Second Author –Dr. Srinivasulu Naidu.S,
Professor of Physiology,
Bangalore Medical College & Research Institute
Corresponding Author –
Dr. Shashikala K.T,
Assistant professor of Physiology,
Bangalore Medical College & Research Institute