Why do diets fail? Is it because of genetic disposition? A sluggish metabolism? An underactive thyroid? A behavioural psychologist reveals the truth about dieting, including how she lost over 50 kg in one year. Why do diets fail? Is it because of genetic disposition? A sluggish metabolism? An underactive thyroid? A behavioural psychologist reveals the truth about dieting, including how she lost over 100lb in one year. After years of failed diets Dr Nadja Hermann weighed over 23 stone at the age of 30. All her life, she had heard and read about hundreds of reasons why diets wouldn't work for her. But when her weight started to seriously affect her health, she took a hard look at the science and realised that most of what she believed about dieting was a myth. What was more, those very myths were preventing her from losing weight. Forget clean eating, paleo, or fasting - it was conquering these elements of 'Fat Logic' that finally led to Hermann achieving a healthy weight. One and a half years later, she weighed 10 stone, and has maintained that weight to this day. Now, using humour, the insight she's acquired, and a dose of science, Hermann debunks widespread lies about weight loss, and shows how it is possible to attain a healthy weight. 'A much-needed corrective.' -Dominic Lawson, Daily Mail