The diet which Beyonce Knowles used to help her lose 20 pounds (nine kilograms) for her latest film role has come under fire from leading dieticians. British newspaper the Daily Express claims the former DESTINY'S CHILD beauty adopted a "maple syrup" diet to shed to pounds as she prepared for her role as DINA in DREAMGIRLS. Knowles reportedly mixed the syrup with water, lemon juice and cayenne pepper - and it constituted her every meal over a period of days. Dietician ALISON CHIPPERFIELD, who works with British group Weight Concern, says, "The problem is not what's in the diet but what's not. "There are no fats, proteins, vitamins or minerals and the only carbohydrate is in the form of sugar... People would start to feel very lethargic and would be unable to concentrate... "They will probably end up in hospital, especially people who try it for more than 10 days."