Obesity is an epidemic that is particularly prevalent amongst aging Americans.The economic literature concerning this phenomenon is blossoming,but largely focuses on its causes. This work examines the issue from a differentdirection. First, a Bayesian model is developed to determine how agingAmericans use obesity related health information, and if their response differsfrom the non-obese. Second, a behavioural model is employed to see if thesame health information elicits a behavioural response in the form of weightloss. This is the first behavioural response model to determine the existenceand magnitude of BMI defined behavioural changes after exposure to newpersonal obesity related risk information. This book is addressed toresearchers in economics, sociology, demographics and professionals in themedical arena.