If you have this book in your hands, you are probably interested in or affected by this scourge in one way or another. It is a study of the eating behaviour of children aged between 5 and 10, looking at the subject of child obesity and fast food. Firstly, we'll look at what obesity is and then describe its characteristics and trends worldwide and in France. All this is backed up by qualitative research to support my arguments and explain why this disease is a 21st century scourge and a serious illness. The subjects of this book are parents and children and their environment. Throughout this research theme, we will try to answer the following question: "How does marketing influence the eating behaviour of children aged 5 to 10?