To obtain estimates of the effects of overweight and obesity on the incidence of type 2 diabetes (T2D) and adult mortality. We use three waves (2000, 2002, 2012) of the Mexican Health and Aging Survey (MHAS).We employ parametric hazard models to estimate mortality and conventional logistic models to estimate incidence of T2D. Obesity and overweight have a strong effect on the incidence of T2D;this, combined with the large impact of diabetes on adult mortality, generates increases in mortality that translate into losses of 2 to 3 years of life expectancy at age 50. If increasing trends in obesity in Mexico continue as in the past, progress in adult survival may be slowed down considerably and the incidence of T2D will continue to increase.