Britney Spears is bingeing on alcohol, food and shopping, it has been claimed.The 25-year-old singer checked into Malibu's Promises rehab centre earlier this year, but sources say she has not changed her ways.A source told America's Star magazine: "Britney is drinking heavily again,binge shopping and eating like there's no tomorrow."On several occasions, I have seen her pouring alcohol into energy drink cans."Britney requests that her alcohol be served in carafes rather than in bottles. Once, a waitress made the mistake of bringing her a bottle. Britney grabbed her arm and told her she couldn't be seen with it."Meanwhile, the 'Toxic' singer's reported feud with her mother Lynne is said to be causing a rift between her and younger sister Jamie Lynn.A source revealed: "Jamie Lynn and Britney have always been close, but Jamie Lynn thinks Britney is being cruel, especially after everything their mom did for her."Jamie Lynn wants it to stop."Last week, Britney's new boyfriend branded her a "practising alcoholic".Alcohol counsellor John Sundahl, who met Britney earlier this year at her Alcoholics Anonymous meetings, admitted the pop star has a drinking problem.He confirmed: "Yes, she is still a practising alcoholic."