An Investigation into the Prevalence of Normal-Weight Obesity in an Adult Caucasian Population Residing in Scotland

Abstract

Introduction: The use of body mass index is the current methodology used to measure obesity in clinical practice. Using body mass index has multiple limitations, including but not limited to the fact that body mass index cannot differentiate between fat mass and lean mass as they both play a role in weight, however both have very separate effects on health and adiposity. The use of body mass index causes a substantial amount of normal weight individuals to be diagnosed as a healthy weight when they are at the same risks of the comorbidities of obesity as an individual within the obese range due to a high body fat percentage. These individuals are categorized as normal-weight obese and prevalence of this varies dependent on the many factors such as ethnicity and the cut-off points used to diagnose normal weight obesity. Hypothesis: There is an estimated prevalence of around 10% for normal weight obesity within the adult Caucasian population at Queen Margaret University (age 18-49). Methodology: This is a cross-sectional study of n=42 18-49 year old students at Queen Margaret University with a normal body mass index (18.5-25.0kg/m2). Anthropometric and body composition measurements were taken by three trained researchers using the same guidelines. Body composition was measured using a Bioelectrical Impedance Analysis machine. VO2 MAX was estimated using a physical activity questionnaire and a 3 day diet diary was acquired from each participant. Normal weight obesity was defined as body fat >23% for males and body fat >30% for females while being within the healthy range for body mass index. Results: Among the 42 participants, 6 were identified as normal weight obesity to give a level of prevalence within the population of 14.29%. Conclusion: There is limited literature on the prevalence of normal weight obesity in the Scottish population and this study serves to estimate current prevalence rates. The study shows that normal weight obesity is an issue in the Scottish population and a longitudinal study with a larger population size should be conducted in an attempt to aid in understanding the situation. This study should include multiple ethnicities and ages amongst other variables. KEY WORDS: Body Mass Index • Normal-Weight Obesity • Physical Activity • Bioelectrical Impedance Analysis • Anthropometry • Body Fat Percentage