Half Ton Mum tells the story of the world's heaviest woman, Renee Williams, a 64-stone, 29-year-old mother of two who, in a desperate bid to lose enough weight to save her life, undergoes life-threatening surgery. Renee, who has realised she wants to be around long enough to see her two daughters grow up, hopes her story will help change the lives of the estimated 2 million Americans who weigh more than 40 stone.