Gillian McKeith (born 28 September 1959) is a Scottish television presenter and writer. She is the former host in the UK of Channel 4's You Are What You Eat and Granada Television's Dr Gillian McKeith's Feel Fab Forever, and as of 2010 presents Eat Yourself Sexy on the W Network in Canada. She is the author of several books about nutrition, including You Are What You Eat (2004), and Dr Gillian McKeith's Ultimate Health Plan (2006).
McKeith advocates a pescetarian diet high in fruits and vegetables, grains, beans, nuts, and tofu, and the avoidance of processed and high-calorie foods, sugar and fat, red meat, alcohol, caffeine, white flour, and additives.
McKeith's work has met with commercial success. You Are What You Eat has sold over two million copies, and in 2005 she was awarded a Consumer Education Award by the Soil Association. At the same time, the validity of her approach and the safety of her recommendations have been strongly criticized by health professionals.