That's a pound every 8 days, or about 0.9 pounds per week. If you add the figures for pasta and bread and the like, the overall starch numbers start getting really high. All of these "complex carbs" break down super fast into pure sugar in the small intestine and almost instantly jack your blood sugar way up and bounce your blood sugar levels around like a yo-yo.
The biggest single offender, however, is still sugar, whether as sucrose or as high-fructose corn syrup (or naturally occurring in fruit or in sweeteners like honey). And the biggest part of that sugar consumption is added sugar rather than naturally occurring sugar in the food. The amount of added sugar is estimated by UCSF at 66 pounds per person per year in the U.S.--which works out to a pound every 5.5 days, or 1.3 pounds per week. Putting it all together, I would guess that Americans get well over 2 pounds per week of total carbs as sugar (i.e., including starches converted to sugar). That, in turn, agrees more or less with the generally accepted claim that modern Americans get about 40% of their calories from carbs, which is arguably too high.
For example, Barry Sears, the PhD physiologist who wrote Enter the Zone, has convincingly argued that 40% calories-as-carbs is way too high for good health. So, to be healthy, you should almost never consume straight (added) sugar (or drink fruit juice) and also eat only pretty small portions of the starchy stuff. (But watch out for some of the artificial sweeteners, too!)
