March 2017, Volume 67, Issue 3

Original Article

Obesity and associated risk factors among students of health colleges of King Saud University, Saudi Arabia: A cross-sectional study

Elshazaly Saeed  ( Prince Abdulla bin Khaled Coeliac Disease Research Chair (PAKCDRC), King Saud University, Saudi Arabia. )
Asaad Mohammed Assiri  ( Pediatric Department, Prince Abdulla bin Khaled Coeliac Disease Research Chair (PAKCDRC), King Saud University, Saudi Arabia. )
Ibrahim AwadEljack  ( Department of Community and Family Medicine, Faculty of Medicine Al-Baha University, Saudi Arabia. )
Abdullah S Aljasser  ( King Saud University College of Medicine, Riyadh, Saudi Arabia. )
Abdulrahman Mohammed Alhuzimi  ( King Saud University College of Medicine, Riyadh, Saudi Arabia. )
Ahmed Assad Assiri  ( King Saud University College of Medicine, Riyadh, Saudi Arabia. )
Nasser Ali Alqahtani  ( King Saud University College of Medicine, Riyadh, Saudi Arabia. )
Saud Amer Alshahrani  ( King Saud University College of Medicine, Riyadh, Saudi Arabia. )
Yousif A Al-Ammar  ( King Saud University College of Medicine, Riyadh, Saudi Arabia. )


Objective: To determine the prevalence of obesity and associated risk factors among medical students in Saudi Arabia.
Methods: The cross-sectional study was conducted from December 2012 to March 2013 at King Saud University, Riyadh, Saudi Arabia. Using stratified sampling technique, undergraduate students of either gender from the health colleges were included. Information was collected through a pretested questionnaire. Measurements of the height and weight were noted and body mass index for all the subjects was calculated.
Results: Of the 292 students, 146(50%) were males and 146(50%) were females. Obesity was found in 40(13.7%)students. It was more prevalent among males than females (p<0.05) and among those who had chronic diseases (p<0.001). Family history of obesity was significantly associated with obesity (p=0.016). No significant association was found between physical activity and obesity (p=0.863).
Conclusions: There was considerable prevalence of obesity among the medical students. Being male, having family history of obesity, and having chronic diseases were important risk factors.
Keywords: Obesity, Prevalence, Students of health colleges, King Saud University, KSU, Saudi Arabia. (JPMA 67: 355; 2017)


Obesity means having too much body fat. It is different from being overweight, which means weighing too much. A person is considered overweight if his or her body mass index (BMI) ranges between 25 and 29.9kg/m2, while a person is considered obese if the BMI is over 30kg/m2.1 Obesity occurs over time when you eat more calories than you use. The balance between calories-in and calories-out differs for each person. Factors that might tip the balance include your genetic makeup, overeating, eating high-fat foods and not being physically active.2
Obesity is important as it is considered a growing problem worldwide, specifically among Saudi males and females.3 Worldwide, the proportion of adults with a BMI of 25 kg/m2 or greater increased between 1980 and 2013 from 28.8% to 36.9% in men, and from 29.8% to 38.0% in women. Prevalence has increased substantially in children and adolescents in developed countries; 23.8% of boys and 22.6% of girls were overweight or obese in 2013. The prevalence of overweight and obesity has also increased in children and adolescents in developing countries from 8·1% to 12.9% in 2013 for boys and from 8.4% to 13.4% in girls. In adults, estimated prevalence of obesity exceeded 50% in men in Tonga and in women in Kuwait, Kiribati, Federated States of Micronesia, Libya, Qatar, Tonga, and Samoa. Since 2006, the increase in adult obesity in developed countries has slowed down.4 In Saudi Arabia,obesity was among the major public health problems. A study done in the Kingdom of Saudi Arabia showed that, of the 10,735 participants evaluated, 28.7% were obese (BMI >30 kg/m2).
There are a variety of factors that play a role in obesity. This makes it a complex health issue to address. Overweight and obesity result from an energy imbalance. This involves eating too many calories and not getting enough physical activity. Body weight is the result of genes, metabolism, behaviour, environment, culture and socioeconomic status. Behaviour and environment play a large role causing people to be overweight and obese.5
Previous studies conducted in Saudi Arabia investigated the prevalence of obesity among Saudi population, but little or no data was available about the prevalence of obesity and associated risk factors among medical students. Epidemiological surveys to determine the prevalence of obesity and associated risk factors are of high importance, especially those targeting university students. Being overweight or obese greatly raises the risk for other health problems; thus, more studies are needed among youths to provide evidence-based data to the health authorities to assist in the design of appropriate strategies in controlling obesity in the study areas. The current study was planned to determine the prevalence of obesity among students of the university health colleges and to identify the associated risk factors in Saudi Arabia.

Subjects and Methods

The cross-sectional study was conducted from December 2012 to March 2013 at King Saud University (KSU), Riyadh, Saudi Arabia. Riyadh is the capital and the largest city of Saudi Arabia. It is also the capital of Riyadh Province, and belongs to the historical regions of Najd and Al-Yamama. It is situated in the centre of the Arabian Peninsula on a large plateau, and is home to 5.7 million people, and the urban centre of a region with a population of close to 7.3 million people.6 KSU is a public university in Riyadh. The university was created to meet the shortage of skilled workers in Saudi Arabia. The student body of KSU consists of about 51,168 students of both genders. The female students have their own disciplinary panel and there is a centre supervising the progress of female students, either personally by female faculty members or by male faculty members via a closed television network.7
The study comprised undergraduate students from five major health colleges under KSU: Medicine, Dentistry, Pharmacy, Applied Health Sciences and Nursing. The study sample was collected from each college proportional to the size of the students\\\' population.
The sample size was estimated using the single population proportion formula: N = (Za +Zb)2 ((r1q1) + (r2q2)) (P1-P2)2 where, p = prevalence of obesity, q1= (1- P1), q2= (1- P2) and Z = standard score which corresponds to 1.96. For calculations, a 95% confidence interval (CI) (z) was used. Equal number of males and females in the study were ensured using stratified simple random sampling.
The prevalence of obesity among male and female aged 18-24 years was taken from a previous study8 as shown below:
PF=15.9 QF=84.1 PM=29.6 QM=70.4 Za=1.96 (95%) ZB=0.842 (80%)
N= {(1.96+0.842)2 [(0.159×0.841) + (0.296×0.704)]} ÷ {(0.159 - 0.296)2} = 292 participants.
Ethical clearance was obtained from the institutional review board, and informed consent was obtained from all the students. Data was collected using a questionnaire that was developed based on possible risk factors and was pretested in a few subjects similar to the study participants for validity. The questionnaire included information such as socio-demographic characteristics, lifestyle factors, family history of obesity, presence or absence of some chronic diseases. The height and weight of all the subjects were measured.
Data analysis was performed using SAS version 9.2 (SAS Institute, Inc., Cary, NC).
Categorical variables were summarised as frequencies and percentages and contentious variables were summarised as mean and standard deviation. Comparison between groups for categorical variable was done using chi-square test or Fisher\\\'s exact test, where for continuous data student t-test or Mann Whitney Utest were used. Multiple logistic regression models with stepwise selection were used to identify multivariate predictors for obesity. To quantify the strength of multivariate association, we used odds ratios (OR) with 95% confidence intervals (CI). P <0.05 was considered statistically significant.


Of the 292 students, 146(50%) each were males and females.The mean age of the students was 21.2±1.2 years (range: 18-24 years). Overall, 193(66.6%) students had a high income, 69(23.8%) had an intermediate income and 28(9.6%) had low income. Overall 40(13.7%) were obese; 37(25.3%) in males and 3(2.1%) in females (Table-1).

Besides, 29(9.9%) students were under weight, 147(50.3%) were normal weight, 76(26.0%) were overweight, 26(8.9%) had obesity World Health Organisation (WHO) class-1, 7(2.4%) had obesity class-2 and 7(2.4%) had obesity class-3 (Table-2).9

Male students were more likely to get obesity compared to female students (p< 0.001) (Table 3).

A total of 20(6.8%) students had chronic diseases, and of those 9(45%) had obesity and 11(55%) were none-obese. The obesity increases among the students suffering from chronic diseases than those who did not have chronic diseases (p<0.001). Obesity increased among students who had family history of obesity (p< 0.01). In the univariate analysis, no statistically significant difference was observed between obesity in students who had physical activity versus those who did not have (p=0.741).
Multiple logistic regression model was also worked out (Table-4).


Prevalence of obesity was higher among women (33.5% vs 24.1%). Among men, obesity was associated with marital status, diet, physical activity, diagnoses of diabetes, hypercholesterolaemia and hypertension. Among women, obesity was associated with marital status, education, history of chronic conditions, and hypertension.10 Worldwide, at least 2.8 million people die each year as a result of being overweight or obese, and an estimated 35.8 million (2.3%) of global disability-adjusted life years (DALYs) are caused by overweight or obesity. Overweight and obesity lead to adverse metabolic effects on blood pressure, cholesterol, triglycerides and insulin resistance. Risks of coronary heart disease, ischaemic stroke and type 2 diabetes mellitus increase steadily with increasing BMI, a measure of weight relative to height. Raised BMI also increases the risk of cancer of the breast, colon, prostate, endometrium, kidney and gall bladder. Mortality rates increase with increasing degrees of overweight, as measured by BMI.11
In the present study, the prevalence of obesity and associated risk factors were estimated among university students. The prevalence of obesity was estimated to be 13.7%. Our data is in agreement with previous reported study done in Kuwait.8 Furthermore, Seubsman S et al12 observed higher prevalence rates of obesity in study done in the Thailand Open University among males with strong association. Similar high prevalence rates were reported among adults, where estimated prevalence of obesity exceeded 50% in men in Tonga and in women in Kuwait, Kiribati, Federated States of Micronesia, Libya, Qatar, Tonga, and Samoa.4 In contrast, lower prevalence rates were reported in both genders in lower middle income countries (7%).11 In the current study, the prevalence of obesity among students of the health colleges in KSU was much lower than that reported earlier in Saudi Arabia by Mansour et al,13 who found 35.5% of adult Saudi people had obesity. These variations might be due to increase in the community awareness about obesity and its related risk factors. Another factor could be the implementation of different prevention programmes at community level which promote leaner and consequently healthier community. This overall decline in obesity prevalence is very good news for the country, especially because there have been few success stories in decreasing obesity levels in other countries resulting from health interventions. Over the last decade, the Saudi Ministry of Health (SMOH) has implemented several public health programmes to reduce obesity. Most of these programmes have focussed on awareness and behavioural changes.14 However,it is too early to determine whether the decline seen in this study is due to SMOH efforts.
According to the WHO classification, most of obese participants were class-I obesity with a percentage of 8.9%, class-II and class-III were the same, which were approximately 2.4%. Also, we found that overweight participants were approximately 26%. Those overweight participants are at high risk to get class-I obesity. It also showed the underweight participants, which was approximately 9.9%. The rest of the participants were normal weight (50%). The obesity in the current study was found to be more prevalent among male students compared to female students and the association was statistically significant. It has been postulated that females are more prone to getting obesity13 than males but our study showed that males were more prone. Many studies showed that females were at high risk of getting obese more than males, but in a different age group other than the age group we studied, such as menopausal females and married women (post-pregnancy and hormonal changes).4,10
According to bivariate analyses, obesity was significantly prevalent among those who had family history of obesity, specially the father and the brother (p= 0.01). A study done in the West Bank showed that there was a relationship between obesity and family history of obesity in both genders.15 This may be explained by the fact that obesity is associated with genetic and familial factors.5 Furthermore, the same study in West Bank showed that obesity was a risk factor for chronic diseases, especially hyperlipidaemia. According to the report of WHO for 2002 which declared that obesity and overweight are the biggest risk factors for non-communicable diseases like high blood pressure, high concentrations of cholesterol in the blood in Gulf region.16,17 Finally, there was no significant result related to lifestyle or physical activity.
We emphasise that the provision of healthcare services, personal education and promotion of lifestyle modification by both governmental and non-governmental organisations can reduce this high prevalence. We advise people who have family history of obesity to control their weight by lifestyle modification and to visit specialists for more information. Also, people with chronic diseases should take their medications regularly and comply with their treatment plans. Males should be more aware about their high risk of getting obese and should try to control their weights with lifestyle modification activities.


The prevalence of obesity was alarming. Being male, having family history of obesity and having chronic diseases were risk factors for contracting obesity.


We are grateful to the administrations of the health colleges of KSU, and to the participating students.
Disclaimer: The manuscript was presented at KuMSA\\\'s Second Annual International Medical & Surgical Updates Conference in Kuwait, held from September 10 to12, 2015.
Conflict of Interest: None.
Source of Funding: The study was financially supported by King Saud University through Vice Deanship of Research Chairs.


1. The challenge of obesity in the WHO European Region and the strategies for response /edited by Francesco Branca, HaikNikogosian and Tim Lobstein. Copenhagen, WHO Regional Office for Europe. [Online] 2007 [cited 2015 April 10]Available from:URL: ua=1.
2. Understanding Obesity. Alabama, United States Health Department, family health Alabama, Mobile County Alabama. [Online] 2015 [cited 2015 April 12]. Available from: URL:
3. Mohammed OA. Obesity among Saudi male adolescents in Riyadh, Saudi Arabia. Saudi Med J. 2003; 24:27-33.
4. Ng M, Fleming T, Robinson M, Thomson B, Graetz N, Margono C,et al. Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2014; 384:766-81.
5. Overweight and Obesity Causes and Consequences. What causes overweight and obesity? Atlanta, USA Division of Nutrition, Physical Activity and Obesity, National Center for Chronic Disease Prevention and Health Promotion, 2012 (Internet communication. [Online] [cited 2015 April 12]. Available from: URL:
6. Riyadh, From Wikipedia, the free encyclopedia (Internet communication.[Online] [cited 2015 April 12]. Available from: URL:
7. King Saud University, From Wikipedia, the free encyclopedia Internet communication. [Online] [cited 2015 April 12]. Available from URL:
8. Hana T. AlMajed, Abdulnabi T. AlAttar, Ali A. Sadek, Thaier A. AlMuaili, Obeid A. AlMutairi,Amna S. Shaghouli, et al. Prevalence of dyslipidemia and obesity among college students in Kuwait. Alex J Med. 2011; 47: 67-71.
9. WHO global database on Body Max Index 2004. Online (Cited 2015 June 11). Available from URL:
10. Memish ZA, El Bcheraoui C, Tuffaha M, Robinson M, Daoud F, Jaber S,et al. Obesity and Associated Factors-Kingdom of Saudi Arabia, 2013. Prev Chronic Dis, 2014; 11:140236.
11. WHO Global Health Observatory (GHO) data > Risk Factors (2015), Obesity Situation and trends, found at ( gho/ncd/risk_factors/obesity_text/en/).
12. Seubsman SA, Lim LL, Banwell C, Sripaiboonkit N, Kelly M, Bain C, et al. Socioeconomic Status, Sex, and Obesity in a Large National Cohort of 15-87-Year-Old Open University Students in Thailand. J Epidemiol. 2010; 20: 13-20.
13. Mansour MA, Yaqoub YA, Mohammed AA. Obesity in KSA. Saudi Med J, 2005; 26: 824-9.
14. KSA Ministry of Health. National campaign against overweight and obesity 2012. [Online] 2012 [Cited 2015 April 12]. Avaliable from URL:
15. Tayem YI, Yaseen NA, Khader WT, Abu Rajab LO, Ramahi AB, Saleh MH. Prevalence and risk factors of obesity and hypertension among students at a central university in the West Bank.Libyan J Med. 2012; 7.
16. Al-Nakeeb Y, Lyons M, Collins P, Al-Nuaim A, Al-Hazzaa H, Duncan MJ, et al. Obesity, physical activity and sedentary behaviour amongst British and Saudi youth: a cross-cultural study. Int J Environ Res Public Health. 2012; 9: 1490-506.
17. WHO. The World Health Report 2002: Global status report on non-communicable diseases 2010. Geneva, Switzerland:World Health Organization, 2011.

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