Credit: Splash News Online

White hot mama!

Just seven weeks after Kate Hudson welcomed son Bingham with fiance Matthew Bellamy, the 32-year-old actress showed off her incredible post-baby body in a tiny white bikini while vacationing in the South of France.

The Something Borrowed star -- who a source tells Us Weekly "didn't gain a lot [of weight] this time around" -- was joined by Bellamy, 33, and her son Ryder, 7 (from her previous marriage to Black Crowes rocker Chris Robinson).

Despite Hudson's trimmer figure, the actress struggled to lose her excess baby weight after she gave birth to Ryder in January 2004.

"Let me tell you something. It's an emotional roller coaster, having to lose weight," she told Marie Claire in June. "I gained so much -- I was 185 lbs at the end." (See more pictures of Kate's white-hot bikini from PopSugar!)

"You actually experience how much energy is stored in that and how much emotion you actually hold in that mass. It is emotional, no matter how determined you are. It takes work to bounce back so quickly."