The 13 percent decrease that Mrs. Obama touted is measured from Spring 2005 through Spring 2011. "Let's Move" was launched in February 2010, so the first five years of the time period in question were prior to Let's Move's existence. The time period for New York City is similar, but the Philadelphia and California figures only extend through 2010, ending just as "Let's Move" got moving.
While the Robert Wood Johnson report demonstrates progress has been made in the struggle against childhood obesity, there's no proof yet that "Let's Move" has played a role, and the report does not mention the program. While "Let's Move" has undoubtedly raised the profile of the issue, the White House will have to wait for the studies to catch up to its claims. Even then, a direct correlation between any change in obesity rates and "Let's Move" will be difficult to verify. But if the White House continues to cite outdated statistics to promote the success of "Let's Move," Mrs. Obama's credibility may be diminished before current figures on childhood obesity become available.