The paper investigates the effects of changes in marital status and health related behaviors (smoking and drinking) on the body mass index (BMI) in Russian adults over a ten-year period. Smoking and drinking behavior changes have played an important part in health status changes over 1994 to 2004. The results indicate that the individual weight/BMI changes asymmetrically in health determinants; the sign and the magnitude of the response are different depending on the starting point and whether there is an increase or a decrease in the explanatory variable. Males' BMI decreases with smoking and increases with quitting smoking, but females' BMI increases with drinking alcohol and decreases with stopping drinking. Losing a partner decreases only the females' BMI, but gaining a spouse/partner is associated with increases in BMI for both genders. For married females and males, the change in spousal BMI is significantly positively related. Understanding interactions between individual health-related behaviors and the set of determinants that contribute to such behaviors is a fundamental step in the design of effective interventions.