Increase of body mass index and waist circumference predicts development of metabolic syndrome criteria in apparently healthy individuals with 2 and 5 years follow-up. 
The metabolic syndrome (MetS) is associated with overweight and abdominal obesity.  Our aim was to use longitudinal measurements to provide clinically relevant information on the relative influence of changes in body mass index (BMI), waist circumference (WC), and weekly physical exercise duration on the development of each of the MetS components.  We analyzed data collected at the Tel-Aviv Medical Center Inflammation Survey (TAMCIS).  Apparently healthy individuals with two consecutive visits that were not treated for any metabolic criteria were included in this study.  We analyzed the influence of changes in BMI, WC, and time engaged in physical exercise on the change in each of the components of the metabolic syndrome using linear regressions.  Included were 7532 individuals (5431 men, 2101 women) with 2 years follow-up.  Participants who gained two BMI points, had the mean number of criteria increase from 1.07 to 1.52, while participants who lost two BMI points, decreased from 1.64 to 1.16.  A long-term analysis over 5 years showed similar results.  Furthermore, an increase in WC was independently associated with increased severity of each of the other components, when controlling for increase in BMI.  Increase in weekly exercise duration had a small but statistically significant favorable effect on blood triglycerides and HDL levels, but not on blood pressure or HbA1C. Changes in BMI and WC are highly associative with the likelihood and severity of the MetS independently of the baseline levels, suggesting that obese individuals can substantially improve their MetS prognosis by losing both body weight and abdominal fat.