This study describes the burden of overweight and obesity and associated risk factors for chronic, non-communicable diseases among newly admitted students of the University of Ibadan. The study participants consisted of adolescents and young adults who came in as freshmen for undergraduate studies and those who had returned or enrolled for postgraduate studies in the University of Ibadan.
Burden of overweight and obesity
The prevalence for overweight and obesity in this study were 18.7 and 7.2% respectively. Similar studies carried out majorly among undergraduates to determine the prevalence of overweight and obesity in Nigerian universities recorded prevalence rates of 16.2% and 4.8% [34] and 25% and 11% [35] respectively. This finding aligns with the overall prevalence for overweight and obesity in a multi-centre study among low-middle income countries including Nigeria which were 22% and 5.8% [12] and in Ghana, 25.8% and 5.9% respectively [36] In this study, overweight and obesity had significant relationships with the older age group, being female and undergoing postgraduate training.
We found a consistently increasing trend of overweight and obesity with age. This trend persists till later years of postgraduate programme depicting increasing risk of obesity at middle age and later in adulthood. This aligns with the findings from the global study of overweight and obesity in children and adults which showed that in both developed and developing countries, successive cohort from 1980 to 2013 tend to gain weight at all ages and the most rapid weight gains occurred between the ages of 20 and 40 years [37]. The persistence in overweight and obesity till later years of study, despite the rigors of academic work in the university, has also been documented in other studies in both LMIC and industrialized countries [7, 12, 38]. This is not surprising given the fact that the students are being exposed to an environment of independence, urban lifestyle with unfettered access to fast food, high sweetened drinks and energy-dense foods without investment in built environment for physical activity. Furthermore, previous study showed that university students lack knowledge about healthy food choices and this has negative influence on their eating habits and nutritional status [39,40]. Where exposure to obesogenic environment persists, students who were underweight are at risk of transition to overweight and obesity across the life course.
Double Burden of Malnutrition
Our findings revealed a double burden of malnutrition characterized by the co-occurrence of undernutrition along with overweight and obesity. In this study, the female gender had a higher burden of abnormal BMI with co-occurrence of underweight, overweight and obesity similar to studies reported in other LMIC [41,42]. Furthermore, there was an increasing shift from undernutrition to overnutrition at each year of entry of the study participants to the University. The double burden of malnutrition documented in this study is similar to findings reported among students of tertiary institutions in different geopolitical regions of Nigeria [35, 43] and other low- and middle-income countries [12]. According to the World Health Organization (WHO), a double burden of malnutrition can be found at individual level comprising abnormal weight with deficiency of one or various vitamins and minerals; at the household level and at the population level – where there is a prevalence of both undernutrition and overweight in the same community, nation or region [5, 44]. Studies emanating from LMIC have documented the coexistence of underweight and overweight within the same family [45,46] and communities [47, [47-49].The occurrence of double burden of malnutrition as found in this study reflects the picture of the general Nigerian population [50] and many developing countries that are experiencing nutrition and socioeconomic transitions [51,52].This strongly implies that environmental, nutrition and socio-economic variables rather than genetic factors are likely responsible for the ongoing dramatic double burden of malnutrition in LMIC.
The double burden of malnutrition is a complex and important phenomenon because of the relationship and biological link between the diverse forms of malnutrition beyond coexistence. For example, a stunted child is more likely to be overweight and/or affected by NCDs as an adult [53]. At the same time, undernutrition in form of nutritional deficiencies is an important underlying risk factor for major communicable diseases and global child mortality [54,55]. Thus, the double burden of malnutrition at a younger age is a silent driver of the double burden of infectious and non-communicable diseases [54] later in life. The phenomenon of dual burden of malnutrition also presents a major public health challenge for the health care system [56].
Our findings underscore three important points. First is that the burgeoning prevalence and pattern of overweight and obesity across the age groups, from different locations suggest a strong environmental/social causative factor deserving further attention as possible target for intervention. Second, the evidence indicates the need to implement lifestyle-related interventions as part of efforts to halt the progression of obesity and prevent the emergence of chronic disease risks later. Third, greater success may be achieved in curbing overnutrition if the prevailing environmental and social factors are explored further for appropriate intervention. While diseases associated with undernutrition remain a major concern at the face of economic and social transitions, LMIC are experiencing a marked increase in overweight and obesity. This implies that overweight and obesity epidemic is unrelenting and may soon dominate the risk profile for chronic diseases if unaddressed. According to WHO, this double burden of malnutrition offers a unique and important opportunity for integrated action on malnutrition in all its forms. There is an urgent need for double-duty actions “which are interventions, programs, and policies that have the potential to simultaneously reduce the risk and burden of under and overnutrition” [5, 54] targeted at the University community and country at large.
Obesity-related health conditions
Hypertension was the most prevalent chronic condition among the study participants and its prevalence was 8.1% which is consistent with the prevalence of a study conducted among Ethiopian students where the prevalence was noted to be 7.4% [57]. Studies indicate that 90% of young people with hypertension have primary or essential hypertension which has no specific cause but well-defined risk factors [58,59,60]. In this study, hypertension had significant relationships with older age group, being a male, undergoing postgraduate studies, overweight or obese and those with a family history of hypertension. As overweight and obesity rates increased among the study population, there was a parallel rise in the prevalence of hypertension across the age-groups. Similar finding has been documented among students of a tertiary institution in Cameroon [38].
Hypertension is the leading cause of death globally and most important risk factor for cardiovascular disease, stroke, and chronic kidney disease (CKD) [33, 61]. Available evidence shows that young people with hypertension have similar target-organ damage such as left ventricular hypertrophy (LVH), microalbuminuria and carotid intimal thickness as older adults with hypertension [62]. LVH is one of the early manifestations and immediate consequences of hypertension. The results of this study showed that only a small proportion of the study participants had Electrocardiography (ECG) done as part of the evaluation for hypertension-related target organ damage. The ECG of about three-quarters of those evaluated revealed LVH. This has to be interpreted with caution because ECG is not validated for diagnosis of LVH in young individuals [63]. A previous study showed that Left ventricular hypertrophy is present in about 20–40 % of children and adolescents with high BP, and represents a compelling indication for starting an antihypertensive drug treatment [64]. LVH and other target organ markers are associated with adverse cardiovascular outcomes and risks for end stage renal disease, retinopathy, ruptured aortic aneurysm, stroke and impaired cognitive function [58, 60]. These complications and their consequences are unlikely to be clinically apparent for many years in adolescence and young adulthood. Thus, there is a need to adapt and follow recommended guidelines for the investigation and management of hypertension and co-morbidities in young people.
Also, our study revealed that a third of the study population (35.1%) had prehypertension. Reports from many studies indicate that prehypertension is common among adolescents and young adults with evidence of target organ damage already present. Prehypertension is not considered a disease category, but identifies those who are likely to progress to stage 1 or stage 2 hypertension in the future [65,66] without intervention. It is a strong predictor of hypertension and future cardiovascular disease [67,68]. The significant relationship between prehypertension and being overweight and obese in this study implies that the burden of hypertension and cardiovascular disease may increase if the obesity epidemic continues to spiral out of control.
Implications for Interventions
Primary prevention remains the most realistic strategy to curb the growing burden of obesity and obesity-related health conditions among adolescents and young people. This is pertinent considering that overweight/obesity and related health conditions documented among adolescents and young adults in this study predates their entry to the university. Unfortunately, the systematic reviews of studies have reported gaps in the number and quality of obesity prevention interventions conducted within the adolescents and young adult age groups in developing countries [69, 70]. Young people represent a unique age group whose views and health needs are not being adequately addressed by the health management information system. For instance, there was apparent neglect of adolescents (with the exception of married female adolescents) during the collection of national data on nutrition during the Nigeria Demographic Health Surveys [50]. In addition, policies and programmes to address nutrition in Nigeria remain skewed towards undernutrition and children under five years [50, 71]. To tackle obesity among Nigerian adolescents and young people, a critical step is the collection of data on its burden, risk factors and trends. Furthermore, there is a need for holistic, synergistic mix of population-level interventions such as the provision of physical activity facilities, coupled with the regulation of labelling, marketing, content and pricing of energy-dense foods and sugar-sweetened beverages which target the obesogenic environment and requires a multi-sectoral approach [71, 72].
The strengths of this study include the large population of adolescent and young people from diverse geographical and social background as participants. Population-based studies on obesity and emerging NCD risks are needed to build an evidence base that socially and culturally reflects the reality in developing countries. This is a novel study that included both undergraduate and postgraduate students covering broad spectrum of adolescents, young and middle-aged adults. Hitherto, studies on obesity and overweight problems were mainly carried out on undergraduate students. The study spans over a ten-year period which shows trends in obesity and hypertension, thus increasing the validity and power of this study. The findings from this study will add to the body of knowledge on the burden of obesity and overweight among university students both in Nigeria and globally which will assist in planning effective health intervention programmes to reduce the heavy burden of obesity noted among university students.
Key limitations include lack of data on dietary intake, physical activity, socio-economic status, smoking and alcohol consumption and other emerging lifestyle risk factors on obesity and overweight which could provide a richer perspective on the factors contributing to the burden of obesity and associated diseases among this population. In addition, another limitation is the use of ECG and not Echocardiography which is the validated test for the diagnosis of LVH in young individuals thereby limiting the usefulness of LVH finding in this study.