Project – Assessment of Obesity and Its Associated Lifestyle Factors among Undergraduate Students

CHAPTER ONE

INTRODUCTION

1.1 Background to the Study

Obesity is a chronic and multifactorial disease characterised by excessive accumulation of body fat that may impair health. It is commonly assessed among adults using body mass index (BMI), with a BMI of 25 kg/m² or higher classified as overweight and 30 kg/m² or higher classified as obesity. The World Health Organization (WHO) recognises obesity as resulting from complex interactions involving dietary behaviour, physical activity, environmental conditions, genetics, neurobiology and broader social and commercial influences. Globally, obesity has increased substantially over recent decades. In 2022, approximately 2.5 billion adults aged 18 years and above were overweight, including more than 890 million adults living with obesity, representing about 16% of the world’s adult population. The increasing burden of obesity has also extended to low- and middle-income countries, where rapid urbanisation, changing food environments and sedentary lifestyles have contributed to changing patterns of body weight and metabolic health (World Health Organization [WHO], 2025).

The growing prevalence of obesity is particularly important because excessive body weight is associated with a wide range of non-communicable diseases. Obesity increases the risk of conditions such as type 2 diabetes, cardiovascular diseases, hypertension, musculoskeletal disorders and certain cancers, thereby contributing to premature morbidity and mortality. The WHO (2025) notes that higher-than-optimal BMI was associated with an estimated 3.7 million deaths from non-communicable diseases in 2021. The health implications are not restricted to older adults, since overweight and obesity established during adolescence and young adulthood can persist into later life. Consequently, university students constitute an important population for obesity assessment because the undergraduate period represents a stage when individuals develop greater independence in food selection, physical activity, sleeping patterns and other lifestyle behaviours that may influence their future health (WHO, 2025).

Nigeria is experiencing the broader global transition in obesity and overweight. A systematic review and meta-analysis by Chukwuonye et al. (2022), involving 33 population-based studies and 37,205 participants, estimated the prevalence of overweight among Nigerian adults at 27.6% and obesity at 14.5%. The prevalence of overweight in the South-West geopolitical zone was estimated at 29.3%, while obesity was also substantial in the region. Another systematic review by Adeloye et al. (2021), involving 35 studies and 52,816 participants, estimated pooled crude prevalence rates of 25.0% for overweight and 14.3% for obesity in Nigeria and reported higher prevalence among urban than rural populations. These findings are important for Lagos because the state is a highly urbanised environment where changes in transportation, food availability, occupation, recreational activities and patterns of sedentary behaviour may influence obesity risk (Adeloye et al., 2021; Chukwuonye et al., 2022).

Dietary behaviour is one of the major lifestyle factors associated with obesity. Changes in food environments have increased access to energy-dense, highly processed foods and sugar-sweetened beverages, while consumption of fruits, vegetables, whole grains and other nutrient-dense foods may be inadequate in some populations. Among Nigerian university undergraduates, Olatona et al. (2018) examined dietary habits and metabolic risk factors across three universities in Lagos State, including the University of Lagos. Among the 506 students studied, only 31.0% reported eating three daily meals, 23.0% ate breakfast regularly and only 2% consumed the recommended daily amount of fruits and vegetables. In addition, 44.0% consumed pastry snacks daily, while 29.0% reported daily consumption of carbonated soft drinks. The study concluded that unhealthy dietary patterns were prevalent among university undergraduates and that obesity and other metabolic risk factors were already relevant within this population (Olatona et al., 2018).

Physical activity represents another important lifestyle factor in the development and prevention of obesity. Regular physical activity increases energy expenditure, supports healthy body weight and provides protection against several non-communicable diseases, whereas prolonged sedentary behaviour can contribute to weight gain and other adverse health outcomes. WHO guidelines recommend that adults undertake between 150 and 300 minutes of moderate-intensity aerobic physical activity per week, or an equivalent amount of vigorous-intensity activity, together with muscle-strengthening activities on at least two days per week. The WHO also emphasises that physical activity can occur through transportation, occupation, recreation, sport and household activities, meaning that assessment of physical activity among university students should extend beyond organised exercise alone (WHO, 2020; WHO, 2021).

Evidence from Nigerian university populations demonstrates the relevance of physical activity and other lifestyle behaviours to students’ nutritional status. A study among undergraduates of Adeleke University in Osun State found that 31.0% of the respondents were overweight and 9.3% were obese, while 35.8% reported seldom engaging in physical activity. The same study found that the majority of respondents consumed snacks daily and identified an association between vegetable consumption and BMI (Oladapo et al., 2020). Similarly, a study involving undergraduate students across universities in Lagos State found abdominal obesity among 5% of participants and reported that obesity was positively associated with alcohol consumption (Olatona et al., 2018). These findings indicate that university students may be exposed to a combination of dietary and behavioural factors capable of influencing body weight, although the magnitude and distribution of these factors can vary between institutions and student populations.

The University of Lagos provides an especially relevant setting for examining obesity and lifestyle factors among undergraduates because previous research has already identified nutritional and metabolic risk factors within the university population. Olatona et al. (2018) included the University of Lagos in a multistage study of undergraduates and selected students from four faculties and eleven departments of UNILAG as part of the wider Lagos university sample. In addition, Esan and Agbaraji (2012) specifically investigated the effect of physical inactivity on BMI among University of Lagos undergraduate students, demonstrating institutional research interest in the relationship between activity and body weight. More recently, Agoro et al. (2020), in a study of 400 University of Lagos Faculty of Education undergraduates, examined students’ perceptions of diet and physical activity as weight-management strategies. These studies provide useful evidence that obesity-related behaviours are relevant within the UNILAG student population; however, there remains a need for a focused assessment that combines actual nutritional status with associated lifestyle factors among undergraduate students across the university population (Olatona et al., 2018; Esan & Agbaraji, 2012; Agoro et al., 2020).

The undergraduate period is therefore an important opportunity for obesity prevention because lifestyle patterns established during young adulthood may influence health trajectories later in life. Research among university students in Lagos has demonstrated nutritional abnormalities, body-image concerns and weight-management practices, including overweight and obesity. A descriptive cross-sectional study of 865 university undergraduates in Lagos reported 10.6% overweight and 7.2% obesity, while only 19.6% of students who engaged in weight-management practices used physical activity as a strategy. The authors also reported substantial body-image dissatisfaction among the students, illustrating that weight status and weight-management behaviours can have nutritional, behavioural and psychosocial dimensions (Ogunleye et al., 2023). Consequently, assessing obesity among University of Lagos undergraduates alongside lifestyle factors such as dietary practices, physical activity, sedentary behaviour, sleep and related behaviours can generate evidence useful for health promotion within the university environment (Ogunleye et al., 2023; WHO, 2025).

1.2 Statement of the Problem

Obesity has become an increasingly important public-health problem globally and in Nigeria. The WHO (2025) reported that 890 million adults were living with obesity worldwide in 2022 and that adult obesity had more than doubled since 1990. Nigeria is also experiencing a substantial burden, with systematic reviews estimating adult obesity prevalence in the range of approximately 14–15%, alongside considerably higher levels of overweight. The situation is particularly important in urban environments, where the availability of energy-dense foods and sedentary lifestyles may contribute to weight gain. Despite the serious health consequences associated with obesity, including diabetes, cardiovascular disease and other chronic conditions, obesity prevention among young adults remains an important public-health concern (WHO, 2025; Adeloye et al., 2021; Chukwuonye et al., 2022).

The problem becomes particularly relevant among university students because the transition into undergraduate life can involve increased independence over food choices, irregular meal patterns, increased consumption of snacks and processed foods, reduced structured physical activity and increased sedentary academic or recreational activities. Evidence from universities in Lagos has already identified several concerning lifestyle patterns. Olatona et al. (2018) found that among 506 university undergraduates in Lagos State, including students from the University of Lagos, only 23% ate breakfast regularly, only 2% consumed the recommended daily amount of fruits and vegetables, 44% consumed pastry snacks daily and 29% consumed carbonated soft drinks daily. The same study found abdominal obesity and other metabolic risk factors among the student population. These findings suggest that unhealthy lifestyle behaviours can exist during early adulthood, before many chronic diseases become clinically apparent (Olatona et al., 2018).

Although previous studies have examined aspects of obesity, dietary habits and physical activity among university students, important gaps remain concerning the current nutritional status of students of the University of Lagos and the lifestyle factors associated with it. For example, previous UNILAG-related research has addressed physical inactivity, weight-management perceptions and dietary/metabolic risk factors, but these studies differed in their objectives, populations, sampling approaches and outcome measures (Esan & Agbaraji, 2012; Agoro et al., 2020; Olatona et al., 2018). Evidence from other Nigerian universities also demonstrates that prevalence and patterns of overweight and obesity differ between student populations. A study at Adeleke University, for instance, reported 31% overweight and 9.3% obesity among undergraduates, illustrating the importance of institution-specific assessment rather than assuming that findings from one university apply directly to another (Oladapo et al., 2020).

There is therefore a need to assess obesity and its associated lifestyle factors specifically among undergraduate students of the University of Lagos. Such an assessment can establish the proportion of students who are overweight or obese and examine relevant behavioural characteristics such as dietary practices, physical activity and sedentary behaviour. A current assessment is also important because university environments and student lifestyles change over time, while evidence from earlier studies may not adequately represent present-day students. The WHO (2025) emphasises that obesity prevention requires attention to healthy diets, regular physical activity and supportive environments, while WHO physical-activity guidelines emphasise the importance of reducing sedentary behaviour and increasing regular activity. Accordingly, investigating obesity and associated lifestyle factors among UNILAG undergraduates can provide evidence for health education, preventive interventions and university-based wellness initiatives (WHO, 2025; WHO, 2020).

1.3 Purpose of the Study

The main purpose of this study is to assess obesity and its associated lifestyle factors among undergraduate students of the University of Lagos.

Specific Objectives

The study will specifically seek to:

1. determine the prevalence of overweight and obesity among undergraduate students of the University of Lagos;
2. assess the dietary habits of undergraduate students of the University of Lagos;
3. determine the level of physical activity among undergraduate students of the University of Lagos;
4. assess the level of sedentary behaviour among the students

1.4 Research Questions

The following research questions will guide the study:

1. What is the prevalence of overweight and obesity among undergraduate students of the University of Lagos?
2. What are the dietary habits of undergraduate students of the University of Lagos?
3. What is the level of physical activity among undergraduate students of the University of Lagos?
4. What is the level of sedentary behaviour among the students?

1.5 Research Hypothesis

The following null hypothesis will be tested at 0.05 level of significance:

H₀: There is no statistically significant association between selected lifestyle factors and obesity among undergraduate students of the University of Lagos.

1.6 Significance of the Study

Undergraduate Students

The study will be beneficial to undergraduate students by providing information on the prevalence of overweight and obesity and the lifestyle behaviours that may be associated with unhealthy weight status. The findings may increase students’ awareness of the importance of balanced dietary practices, regular physical activity and reduction of prolonged sedentary behaviour.

University of Lagos Management

The findings will provide the University of Lagos management with evidence concerning the nutritional and lifestyle characteristics of its undergraduate population. Such evidence may support the development or strengthening of student wellness programmes, physical activity initiatives, nutrition education and other preventive health activities.

University Health Services

The study will be useful to health professionals working within the University of Lagos health system. Information obtained from the study may assist in identifying students who require nutritional counselling, weight-management support, physical-activity counselling or further health assessment.

Public-Health Practitioners

The findings will contribute to public-health knowledge concerning obesity among young adults in an urban Nigerian university environment. Public-health practitioners may use the evidence to develop interventions that address dietary behaviour, physical inactivity and sedentary lifestyles.

Government and Health Policymakers

The study may provide additional evidence for policymakers concerned with the prevention of obesity and non-communicable diseases among young Nigerians. Since university students constitute an important young-adult population, evidence from the study may contribute to broader health-promotion planning.

Researchers and Students

The study will serve as a reference for future researchers investigating obesity, nutritional status, physical activity, dietary habits and non-communicable disease risk among Nigerian university students. It may also identify areas requiring further investigation.

1.7 Scope of the Study

The study will focus on the assessment of obesity and associated lifestyle factors among undergraduate students of the University of Lagos.

The geographical scope will be restricted to the University of Lagos, Akoka, Lagos State, Nigeria.

The population scope will consist of registered undergraduate students of the University of Lagos who meet the inclusion criteria for participation in the study.

The study will examine nutritional status using anthropometric indicators, particularly weight, height and body mass index. Where applicable, other measures such as waist circumference may be included to provide additional information concerning central obesity.

The lifestyle scope will cover dietary habits, physical activity and sedentary behaviour. Dietary assessment may include frequency of consumption of fruits and vegetables, snacks, fast foods, fried foods, sugar-sweetened beverages and other commonly consumed food categories. Physical activity assessment will include exercise, active transportation, recreational activities and other forms of physical activity.

The study will not primarily investigate clinical causes of obesity such as endocrine disorders or medication-induced weight gain. Its main emphasis will be on obesity and selected lifestyle-related factors among undergraduate students.

1.8 Operational Definition of Terms

Obesity: A chronic condition characterised by excessive accumulation of body fat that may impair health. In this study, obesity among adults will primarily be operationalised using a BMI of 30 kg/m² or above, consistent with WHO adult classification.

Overweight: A BMI of 25.0–29.9 kg/m² in an adult.

Body Mass Index (BMI): A measure of body weight relative to height, calculated by dividing weight in kilograms by height in metres squared (kg/m²).

Lifestyle Factors: Behavioural and daily living characteristics that may influence health and body weight, including dietary habits, physical activity and sedentary behaviour.

Dietary Habits: The regular pattern of food and beverage consumption of an individual, including the frequency and types of foods and drinks consumed.

Physical Activity: Any bodily movement produced by skeletal muscles that requires energy expenditure, including exercise, walking, sports, transportation-related activity, occupational activity and household activities.

Sedentary Behaviour: Waking behaviour characterised by very low energy expenditure while sitting, reclining or lying down, such as prolonged television viewing, recreational screen use or sitting for extended periods.

Undergraduate Student: A student formally enrolled in an undergraduate programme at the University of Lagos during the period of the study.

University of Lagos: A federal university located at Akoka, Lagos State, Nigeria, and the institutional setting of the present study.

Associated Lifestyle Factors: Lifestyle characteristics that demonstrate a statistical relationship with obesity among the students studied. These may include dietary practices, physical activity and sedentary behaviour.

Nutritional Status: The state of an individual’s nutrition as reflected in anthropometric measurements and classified in this study primarily through BMI categories.

Project – Assessment of Obesity and Its Associated Lifestyle Factors among Undergraduate Students