Our collective weight is going up. The average American male has gained 17.1 pounds and the average American female has added 15.4 pounds since 1988.

The amount of weight gained has varied across the states. For example, in Iowa, the average weight gain for males is 10.9 pounds - just slightly more than half a pound per year. In contrast, the average weight gain for males in Texas is 24.2 pounds - over 1 pound per year. For females, this ranged from 6.3 pounds in Wisconsin to 26.2 pounds in New Jersey. The tables below show the weight gain by gender for every state.

Methodology

Data for the analysis came from the 1988 through 2008 Behavioral Risk Surveillance System (BRFSS) files. Census population projections were used to adjust the data for changing age profiles over the two decades.

Average weight and height for 1988 and 2008 were estimated for six age cohorts for both females and males. For states not reporting data in 1988, the height and weight of the state was estimated using linear regression from available subsequent years.

The average weight for all cohorts in 1988 was adjusted for changes in the average height (in inches) over the last two decades as follows: Adjusted 1988 Weight = (Measured 1988 Weight) x (Average Height in 2008)2 / (Average Height in 1988)2. This adjustment is analogous to the ratio used in the BMI calculations.

The difference between the measured 2008 weight and the adjusted 1988 weight was calculated for each cohort and the results for the six age cohorts of a gender were weighted by the proportion of the adult population of that gender represented in 2008 in the state. Cohort contributions were summed and resulted in the final weight gain reported for the gender.