Who are Obese? Prevalence and Lifestyle Characteristics Associated with Normal-Weight Obesity in the National FINRISK 2012 Study (Finland)
A syndrome called normal-weight obesity (NWO) has recently been identified among normal weight subjects (BMI<25 kg/m2) whose body composition is not favorable to health. The aim was to compare the lifestyle characteristics (age, education, leisure-time physical activity, smoking habits and alcohol consumption) of NWO subjects with lean and overweight subjects.
METHODS:
The cross-sectional National FINRISK 2012 Study with a health examination and questionnaires included 5827 subjects (25‑74 years). The participation rate was 59% for the health examination including, e.g., anthropometric measures. Together, 390 participants (7%) were considered as non-eligible because of missing measures or pregnancy. Consequently, the final data included 2617 men and 2820 women. NWO was defined as BMI<25 kg/m2 linked with different cut-points of body fat by genders, for men (>20%) and women (>30%). Three weight categories were obtained called as lean, NWO syndrome and at least overweight. The multivariate models were adjusted for obesity related factors (F-test, Wald Chi-Square, p‑value<0.05).
RESULTS: The prevalence of normal weight subjects was 33% in men and 47% in women. Of those, 29% of men and 40% of women were NWO (among all subjects: 10% and 19%, respectively). In all, 0.2% of NWO men and 9% of women had abdominal obesity (waist>102 cm in men and >88 cm in women). NWO men were as physically inactive as overweight men whereas their smoking habits and alcohol consumption reminded more lean men. In NWO women, the prevalence of being physically inactive fell between lean and overweight women. They also consumed the most alcohol compared with the other women.
CONCLUSIONS:
From the public health perspective, the proportion of NWO subjects was surprisingly high. The identification of them may be of importance because although they appear lean, they have some unhealthy lifestyle related to obesity and overall health.