Morbid obesity in Taiwan: Prevalence, trends, associated social demographics, and lifestyle factors.

OBJECTIVE: Obesity is one of the most important public health issues worldwide. Moreover, an extreme phenotype, morbid obesity (MO) has insidiously become a global problem. Therefore, we aimed to document the prevalence trend and to unveil the epidemiological characteristics of MO in Taiwan.

METHODS: Nationally representative samples aged 19 years and above from three consecutive waves of Nutrition and Health survey in Taiwan: 1993-1996, 2005-2008, and 2013-2014 (n = 3,071; 1,673; and 1,440; respectively) were analyzed for prevalence trend. And 39 MO (BMI ≥35 kg/m2) cases from the two recent surveys compared with 156 age, gender, and survey-matched normal weight controls (BMI: 18.5-24 kg/m2) for epidemiological characteristics study. The reduced rank regression analysis was used to find dietary pattern associated with MO.

RESULTS: The prevalence of overweight and obesity together (BMI ≥24 kg/m2) was stabilized in the recent two surveys, but that of MO (0.4%, 0.6%, to 1.4%) and obesity (BMI ≥27 kg/m2) (11.8%, 17.9%, to 22.0%) increased sharply. MO cases tended to have lower levels of education, personal income, and physical activity. Furthermore, their dietary pattern featured with a higher consumption frequency of red meat, processed animal products, and sweets/sweetened beverage, but lower frequencies of fresh fruits, nuts, breakfast cereal, and dairy products.

CONCLUSION: This study documents a polarization phenomenon with smaller proportion of overweight people at the center and higher proportions of normal weight and obesity subjects at two extremes. MO was associated with low socioeconomic status and poor dietary pattern. The obesogenic dietary pattern became more prevalent in later time.