The Happiness Handbook uses the principles of positive psychology to help people get what they really want from life. The CHOOSE tool is particularly powerful (Clarity, Healthy Living, Optimism, Others, Strengths, Enjoy). The 3rd edition is updated to include information on The Happiness Diet which uses positive psychology to assist individuals with weight problems on both sides of the normal range. In The Happiness Handbook, Dr Sharp distills the findings and advances in positive psychology research into a range of simple but effective plans designed to increase happiness levels. He says: There is no doubt that happiness is something you choose - and the CHOOSE model will help you make more decisions that will lead to more happiness. The Happiness Diet is a psychological program based on the principles of positive psychology that has been specifically designed to help individuals with weight problems. Dr Sharp believes that ultimately, all diets fail because they only address WHAT people eat as opposed to WHY they eat. The Happiness Diet pays equal attention to the what and the why and includes nutrition, exercise and psychology components.