This descriptive cross-sectional survey was conducted at Obafemi Awolowo University, Ile-Ife, Nigeria from April 2017 to June 2017. It is a federal government owned and operated Nigerian university situated on a vast expanse of land totaling 11,681 hectares in Ile-Ife, Osun State, Southwest, Nigeria. The university was founded in 1961, and offers undergraduate and postgraduate degree programmes in multiple fields of study ranging from humanities, the arts, natural sciences, engineering, technology and medical sciences, with a student population of about thirty-five thousand. The University comprises of central campus, the student residential area, the staff quarters and a Teaching and Research Farm. The campus is built on about 5,000 acres (20km2) and comprises of academic, administrative units and service centres. The student residential area is made up of 10 undergraduate hostels and a postgraduate hall of residence. The academic area is not too far from the residential area. Many restaurants and fast food joints are located both in the academic area, as well as, in the residential area. Selected undergraduates of Obafemi Awolowo University in the chosen departments and who are willing, participated in the study.
The sample size was calculated using Leslie Fischer’s formula for a single population proportion [n=Z2 p (1-p) / d2]. The prevalence of university students with good knowledge of obesity was 49.8% from a previous study , with a 95% CI and precision of 5%. After accounting for a non-response rate of 10%, the total sample size was rounded up to 423. Multi-stage sampling technique was used in selecting participants. In the first stage, the College of Health Sciences, Faculty of Pharmacy, and Faculty of Agriculture were excluded based on the assumption that they might have been exposed to relevant teachings on obesity. Out of the remaining eight faculties that met the inclusion criteria, five faculties were selected using the simple random technique (balloting method). These were faculties of Law, Administration, Education, Social sciences and Arts. In the second stage, three departments were selected in each of the five faculties by simple random technique (balloting method) with the exception of faculty of Law which has only one department. The third stage involves proportionate allocation of the sample based on the estimated number of students available in each department and the selection of participants by simple random sampling technique (balloting method).
A structured self-administered questionnaire which had four sections was used to collect data from the respondents. The questionnaire contained 11 questions to assess the respondent’s knowledge of obesity, 16 questions to assess the perception of obesity and food frequency questionnaire to assess the dietary behaviour of participants. The questions on obesity knowledge and perception were adapted from previously published research work.[15–17] The questionnaire was pretested among 40 undergraduates in other faculties not included in the study to check for ambiguity, and all the necessary corrections were effected.
Variables and measures
Obesity knowledge questions assessed the respondent’s awareness, sources of information, basic knowledge and assessment method of obesity. The 11 questions were scored 1 for correct response and incorrect response 0 with the score range between 0-20 points. A score greater than or equals to the mean (10 points) was graded good knowledge and vice versa. The perception questions were measured with a 4-point Likert scale. For every positive question, strongly agree (SA) carries the highest mark and a reverse score for every negative question. The total obtainable score ranged between 16-64 points. A score below the median score was classified as negative and above as positive. Food frequency questionnaire was used to assess the dietary intake of 7 food groups (fruit, vegetable, fried foods, sweets, fatty snacks, soft drinks, barbecue/Suya) that are common in the study location and are likely to lead to excessive weight gain if consumed too often. The frequencies of consumption of these foods per week (once/week, 1-2 times/week, 3-4 times/week, 5-6 times/week and every day) were constructed based on previous studies.[18,19] Intake of healthy foods, including fruit and vegetables, was dichotomized to less than 5 times/week (unacceptable) and more than 5 times/week (acceptable). While intake of unhealthy food, including sugary drinks, fatty snacks, fried foods and barbecue were dichotomized to 2 times/week or less (acceptable) and more than 2 times/week (unacceptable). The total obtainable score ranged between 0-7 points. A score below the median score (4 points) was classified as poor dietary behaviour and vice versa.
Statistical analysis was done by means of SPSS version 20. At Univariate level, descriptive statistics was done to analyze descriptive data and the results are presented as frequencies and percentages for categorical variables and as means and standard deviations for continuous variables. Knowledge, perception and dietary behaviour scores were computed with +1 for a correct response and 0 for an incorrect response. These scores were graded as good or poor knowledge, positive and negative perception, good and poor dietary behaviour using the mean and median scores as the cut-offs. Bivariate chi-square test was done to assess the relationships between knowledge of obesity, perception and dietary behaviour. The statistical significance level was set at p < 0.05. Ethical clearance was obtained from the Research and Ethical Committee of the Institute of Public Health, Obafemi Awolowo University, Ile-Ife. Written informed consent was obtained from the participants. Confidentiality was maintained by using serial numbers instead of names and keeping the data in a pass-worded computer.