Identification of the prevalence of normal weight obesity in a Caucasian population in Scotland.
Background: Normal-weight obesity is a syndrome with increased cardiometabolic risk factors, greater mortality risk and diminished cardiac function compared to normal-weight lean individuals. It is also associated, similarly to obesity, with low-grade proinflammatory status, increased oxidative stress, insulin resistance, and dyslipidaemia. Aims and Objectives: The aim of this study was to identify the prevalence of normal-weight obesity in a normal-weight Caucasian adult population. The objectives were to compare body fat, energy and nutrient intake and physical fitness between normal-weight obese and normal-weight lean participants. Design and Methods: A cross-sectional study of a normal-weight Caucasian population within Scotland (n = 42, 74% female). Body composition was estimated via bioelectrical impedance analysis, maximal oxygen uptake (VO2MAX) was estimated using a physical activity questionnaire and dietary intake was collected via a 3-day diet diary and assessed using Nutritics. Normal-weight Obesity was defined as normal BMI (18.5 ≤ BMI < 25 kg/m2) and body fat >23% in males and >30% in females. Results: Among normal-weight adults, 14.3% were defined as normal-weight obese (n = 6). No difference was observed between normal-weight obese and normal-weight lean individuals in physical fitness, energy and nutrient intake, however, there was a trend for low VO2MAX in Normal-weight obese females (p = 0.051). Body fat was negatively correlated with physical fitness in females but not in the male population. Those with higher body fat % were shorter, weighed less, consumed less energy, less carbohydrate and less protein (p<0.01). Conclusion: A prevalence of 14.3% normal-weight obesity was found within the study group. Normal-weight Obesity was not significantly associated with physical fitness or dietary intake in males or females (p>0.05). There was a significant negative correlation between physical fitness (VO2MAX) and body fat in female subjects but not males (p<0.05) Higher-powered studies are recommended to conclude the prevalence of Normal-weight Obesity and its association with physical fitness and dietary intake in a broader population. Keywords: Normal-weight Obesity, VO2MAX, Body fat percentage, Body composition, Dietary Intake, Obesity