I have spoken to geneticists, molecular biologists, economists, biochemists, neuroscientists, addiction researchers, psychologists, microbiologists, psychiatrists, philosophers, dietitians, nutritionists, sociologists, eating disorder specialists, medical doctors, endocrinologists, geographers, and sensory scientists. I have spoken to those who dedicate their lives to helping obese people, and to others who live with their own larger bodies every day. Everyone I spoke to had their own specialism and knowledge, and each gave me something unique and interesting to think about. Many of them are quoted in the text, but others simply helped me increase my understanding. Although I had differing lines of enquiry for everyone, I ended each interview with a couple of common questions. I asked everybody what they thought the main reasons were that obesity continues to rise, and what might be done to bring it down.