The TV chef said that seven to 11 portions of fruit and vegetables are necessary for "measurable benefits".
Oliver said he believes the public can handle the “truth” about consuming more produce, despite the NHS and World Health Organisation recommending five portions (80g each) daily.
A study published in Clinical Nutrition earlier this year supported Oliver's view, confirming that 11 portions of fruit and vegetables a day are linked to better health outcomes.
Oliver's new book, Eat Yourself Healthy, which includes recipes with up to 11 portions of fruit and vegetables, is set to be released on 11 September.