Health advice on smoothies should be updated to show they contain two of the recommended five portions of fruit and vegetables a day, a leading dietician has claimed.

Writing in the British Nutrition Foundation's journal Nutrition Bulletin, dietician Dr Carrie Ruxton said smoothies contained at least one 80g portion of mashed fruit and a portion of juice, giving them two portions of the recommended five-a-day.

“The nutritional benefits offered by smoothies far outweigh any risks, and a reevaluation of the five-a-day criteria is justified," she said.