Lim YM, et al. - In a general Asian population, researchers evaluated the impact of variability in body mass index (BMI) on the incidence of new-onset atrial fibrillation (AF), stroke, cardiovascular (CV) risk factors, and CV outcomes. Using data from the National Health Insurance Service–Health Screening cohort in Korea, 171,324 patients without AF were involved; BMI measurements occurred biennially from January 1, 2002, through December 31, 2009. Findings suggested that BMI variability, particularly weight gain, was related to increased risk of new-onset AF and myocardial infarction in the underweight and normal-weight Asian population. In order to improve CV results, it is important to avoid weight gain.