Chapter 1: Introduction: Comorbidity: What is it and why is it important?; Rhonda Brown and Einar Thorsteinsson.- Chapter 2: Models of Comorbidity; Rhonda Brown and Einar Thorsteinsson.- Chapter 3: Overweight/Obesity and Concurrent Disorders, Symptoms, Behaviour and Body Temperature; Rhonda Brown and Yasmine Umar.- Chapter 4: Overview of the Comorbidity between Medical Illnesses and Overweight/ Obesity; Christopher J Nolan.- Chapter 5: Comorbid Eating Disorders; C. Laird Birmingham.- Chapter 6: Comorbid psychiatric illnesses; Einar Thorsteinsson and Rhonda Brown.- Chapter 7: Arousal States, Symptoms, Behaviour, Sleep, and Body Temperature; Rhonda Brown and Einar Thorsteinsson.- Chapter 8: Design, statistical and methodological considerations: Comorbidity; Einar Thorsteinsson and Rhonda Brown.- Chapter 9: Typing It All Together; Rhonda Brown and Einar Thorsteinsson.