Senior Policy Advisor for Healthy Food Initiatives Sam Kass was at the US Open on Saturday, Sept. 1 to promote the Let's Move! campaign, swapping his knives for a tennis racket to hit with a gang of kids. By Presidential Proclamation, September is National Childhood Obesity Awareness Month, and the US Tennis Association hosted a youth clinic to kick it off.The organization has thrown major support behind First Lady Michelle Obama's campaign, offering junior tennis opportunities to thousands of kids across the nation.