David Lewis (Author) Dr David Lewis is a neuropsychologist, director of research at Mindlab International, and the author of more than two dozen bestselling books. He is a Chartered Member of the British Psychological Society, a Fellow of the International Stress Management Association, and founder of Action on Phobias and Stresswatch; a non-profit charity advising companies on stress management. He has also been the on-screen consultant to Channel 4's acclaimed Secret Eaters diet programme. Margaret Leitch (Author) Dr Margaret Leitch is a research scientist with PhD, MSc, and Honours BA degrees in the field of Experimental Psychology, Research Methods and Statistics, and Honours Psychology. She has conducted research into the psychological and neuroscientific underpinnings of obesity, including three years of longitudinal patient monitoring. She is a specialist in identifying the predictive signs that express a vulnerability for developing overeating habits. She is co-author of the best-selling book Lose It Right.