Christie called out Letterman for his habit of making weight-related jokes about the him, and even jokingly pulled out a donut in the middle of the interview.

On Tuesday’s PoliticsNation, Rev. Sharpton cheered on Christie for being willing to “have fun” and joke around, but he also offered to give Christie some advice about losing weight.

“Governor, if you’re ever serious about dieting, I know a guy you can get some advice from,” he said. “Call me.”

Sharpton knows a thing or two about weight loss, having dropped more than 100 lbs since he began a serious diet and exercise regimen some years ago. That plan includes daily exercise and a strict diet focusing on salads and the occasional dinner with fish.

Christie reiterated to reporters on Tuesday that he’s concerned about his weight, and that he has good and bad times while working to control it.

“I’m making the best effort I can, and sometimes I’m successful and other times I’m not,” he said. “And other times periods of great success are followed by periods of great failure.”

Click here to read more.